Aristotles Physics and Its Medieval Varieties
Aristotles Physics and Its Medieval Varieties
Aristotles Physics and Its Medieval Varieties
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Aristotle's Physics and lts Medieval Varieties
Helen S. Lang
Published by
State University of New York Press, Albany
Acknowledgments ix
Introduction 1
Notes 189
Bibliography 285
Index of Names 313
Index of Subjects 319
Acknowl.edgments
The project presented here has been long in the making. My study of
the arguments of Aristotle's Plrysics and medieval interpretations of them be
gan some twenty years ago. Over these years, my own sense of the arguments,
both their form and content, has changed considerably.
A number of the chapters in this book appeared earlier, although often
in quite a different guise. Chapter 3, "Why Fire Goes Up," appeared in The
Re1liew of Mer.aphysics, 38 (1984): 69-106 as did Chapter 4, "Being On the
Edge in Plrysics 8.10," under the title "Aristotle's lmmaterial Mover and the
Problem of Location in Plrysics VIII" (The Re11iew of Mer.aphysics, 35 (1981):
321-335) and Chapter 7, "The Structure of Physics for Aristotle, Thomas
and Buridan," under the title "Aristotelian Physics: Teleological Procedure
in Aristotle, Thomas, and Buridan" (The .Re1liew of Mer.aphysics 42 (1989):
569-591). Chapter 8, "Duns Scotus: Putting Angels in Their Place," origi·
nally appeared as "The Concept of Place: Aristode's Physics and the Angelo
logy of Duns Scotus in Viator: Medieval and Renaissance Studies, 14 (1983):
245-266. In each case, there has been considerable re-examination of the
problem at band. The speculation about Homer and the bed of Odysseus ap
pearing at the end of Chapter 1, "Aristotle's Definition of Nature," first ap·
peared as "A Homeric Echo in Aristotle" in Philological Quarterly 61 (1983):
329-39 and some of the material in Chapter 2, "Parts, Wholes, and Motion:
Plrysics 7.1," appeared in "God or Soul: The Problem of the First Mover in
Plrysics VII." Paideia: Special Aristotle Issue 52 (1978): 86-104.
As with any project such as this one, I owe a considerable debt to those
who have helped me in so many ways. So it is with pleasure that I thank
James Bradley, W. Miller Brown, Robert Brumbaugh, William Carroll,
Howard Delong, Drew Hyland, Jeffrey Kaimowitz, David Konstan, Richard
T. Lee, A. D. Macro, Paul J. W. Miller, Donald Morrison, and Fr. Joseph
Owens. And last in order but first in importance, Berel Lang.
I wish also to thank the National Endowment for the Humanities
whose support made the final work on this book possible.
ix
Introduction
2
Introduction
tional, and this convention is not wholly arbitrary. Düring and others have
argued persuasively that our present Corpus Aristorelicum derives from the
edition of Andronicus and that "Andronicus worked with Aristode's original
manuscripts as a base. " 2 Thus, the corpus as we have it may not be imme
diately from the pen of Aristotle, but with some historical basis we refer it
to Aristotle.
The problem of the chronology of Aristotle's works or even the books
within a single work is more problematic. Since Jaeger first published his ar
gument for a chronological ordering of Aristotle's works, efforts to date and
arrange the works and individual treatises within them have continued, al
though they have not met with much success. 3 These efforts assume that Ar
istotle did not spend his entire life elaborating a basic conception arrived at
early on, but rather, that his thought developed over the long period during
which he wrote; therefore, a correct chronology of his writings should pro
vide a key to the development of his thought. 4 Likewise, the daim contin
ues, failure to establish this chronology leaves us with the impossible tasks
both of considering individual works as if they could stand outside this de
velopment and of moving among arguments in different texts without know
ing their respective places within the development of the whole.
But eftorts to establish a chronology require several assumptions. I shall
consider the two most serious: (1) Aristode's arguments stand as parts that
cannot be analyzed independently of their genesis within a whole, and (2)
the larger chronological whole supersedes the logical integrity of Aristotle's
arguments as expressed in the individual treatises.
(1) Any attempt to establish "Aristotle's development" must assume a
whole within which "early" means "Platonic," immature, undeveloped, re
vised (or rejected) later, while "late" means "un-Platonic," mature, devel
oped, final. In short, decisions of chronology depend upon evaluation of
content. The decision that a book is early entails the view that its argument
must be immature, incomplete, and of little (or no) value relative to Aris
totle's "final position." Likewise, if another book is late, then its argument
must be mature and hold a superior position within Aristotle's thought.
But there is virtually no independent evidence for the chronology of
Aristotle's works; rather, evidence for various proposed chronologies derives
from analysis of the arguments themselves. Consequently, far from providing
grounds for assessing Aristotle's development, the chronology itself is pro
duced by textual analysis. 5 Indeed, virtually all disagreement about the prob
lem of chronology rests on conflicting interpretations of arguments.
ln chapter 2, I provide an important example of this problem. Solmsen
speaks of Plrysics 7 as a first, early, "abortive attempt" to reach the first prin
ciple of motion; according to Solmsen, it is replaced by a second, later, and
successful attempt, that is, Plrysics 8. 6 Jaeger, too, classifies Plrysics 7 as early
(largely Platonic): "That it belongs to the oldest part, and arose at a time
3
Aristode's Physics and lts Mediewl Varieties
when he did not yet regard the theory of ideas as simply exploded, is more
than probable."7 And such is indeed the standard view of these arguments.8
But Plrysics 7 is classified as early not on independent evidence about its chro
nological position in the Aristotelian corpus, but because it has been judged
a wealc., if not invalid, argument for a first cause of motion.9
Analyzing the structure and concepts of the argument of Plrysics 7.1, I
argue in chapter 2 not only that this argument is valid, but that it possesses
a different thesis than does Plrysics 8. Indeed, I argue, neither boolc. is a search
for a first principle of motion, strictly spealc.ing. Plrysics 7 is a proof, according
to Aristotle, that "everything moved is moved by another," while Plrysics 8 is
a proof that motion in things must be eternal. Far from being replaced by
Plrysics 8, Plrysics 7 is an independent argument playing a crucial and indis
pensable role in Aristotle's physics. Furthermore, it presents Aristotle's most
extended refutation of Plato's account of soul as a self-mover. (ln chapter 3,
I argue that the first movers of Plrysics 7, Plrysics 8, and Meraplrysics 12 cannot
without further qualification be conjoined to form a single subject matter.)
Far from being immature, invalid, or "Platonic," the argument of Plrysics 7 is
sophisticated, valid, and anti-Platonic.
The same problem infects virtually ail arguments about the chronology
of Aristotle's worlc.s. To establish either the chronology of Aristotle's worlc.s ar
an assessment c:l positions as immature or mature within a developing whole,
there must be sufficient evidence to establish one variable independently of
the other. But in point of fact, we do not lcnow with certainty either which
worlc.s are early or which position(s) mature. On these grounds alone, it may
be impossible to solve either the problem of chronology or the problem of
identifying positions as immature or mature.10 In these matters, working in
two unlc.nowns will not produce a lc.nown result-merely an arbitrary one.11
Furthermore, the dichotomy between a developing Aristotle with early
and later (immature/mature Platonic/un-Platonic) positions versus a fixed
Aristotle elaborating an initial "early" conception may itself be false and
misleading. It presupposes both that Aristotle's various writings are fixed and
that there is some systematic whole within which they operate as parts. Once
such a whole is assumed, it must as a whole be established before we can deal
with the parts (i.e., individual treatises) within that whole.
Jaeger's insistence on the importance of this point for Aristotle's sci-
entific worlc.s male.es the point in one of its strongest versions:
4
Introduction
5
Aristode's Physics and lts Mediewl Varieâes
6
represent not the chronology of Aristotle's arguments but the understanding
of whoever constitutes the divisions and attributes them to Aristotle.
But a more important issue is at stalce in the possibility of a chrono•
logical analysis of the logoi. Even if we grant that different parts of a logos
were written at different times, and even if we could agree about the dating
of the units within the logoi, it still would not follow that within the logos,
parts of arguments are detachable and best read in conjunction with parts
taken from other logoi but belonging to the same "period."26 Revising a worlc
means rewriting at a later date either on the basis of new evidence and a
fullet' understanding of the problem, or in the face of unanticipated objec
tions. But revisions produce not a patchwork of old and new arguments, but a
new whole-that is, a new argument. Whether in Aristotle's logos or in some
other form, the overall argument must retain its integrity as an argument.
The real problem here concerns where the integrity of Aristotle's ar·
guments lies. To subdivide each logos and realign the arguments within them
implicitly denies (on the basis of some larger whole itself established on the
basis of substantive analysis) the integrity of the individual logos as an
argument. 27 Indeed, only arguments that may be identified as written at the
same time retain their integrity as arguments. Here chronology, itself resting
on an analysis of the arguments, becomes a determinative principle for those
arguments. But rearranging Aristode's arguments amounts to destroying the
logical structure of the logos in favor of a hypothetical whole, "Aristode's cor
pus," constructed by a reader on the basis of prior analysis. As a result, the
purpose, domain, and even content of the arguments within the logos, our
closest access to the writing of Aristotle, are often redefined.
ln connection with the problem of the integrity of Aristotle's argu•
ments, we can identify the most serious problems entailed by the thesis of an
early "Platonizing Aristotle." As Owen points out, "The catchword 'Platon•
ism' . • . is too often talcen on trust, and too riddled with ambiguity to be
trusted."28 Plato, it is often argued, went through a genesis of bis own-did
he ultimately reject the forms? lt is hard to see how a criterion not itself
clearly defined can determine Aristotle's development.
But there is a deeper problem with the "Platonism" of Aristotle. It pro
duces a reading of Aristotle that fails to consider bis arguments as such;
rather, one combs through them in search of "Platonic elements. " 29 But such
·a procedure ignores not only the integrity of Aristotle's position as expressed
by bis arguments within a logos, but also the integrity of Plato's position ex
pressed by bis arguments within the dialogues. Bits and pieces extracted from
Plato are identified as bits and pieces in Aristotle. Finally neither Plato's nor
Aristotle's position can be construed, and it is impossible to lcnow what "bor
rowing" or "influence" means here. 30
The fact that Aristotle was Plato's student for twenty years reveals the
origins of many of Aristode's terms and perhaps some of his concepts. But it
7
Aristotle's Physics and lts Mediewl Varieties
does not follow either from his biography or from his language or even from
some of his concepts that his position as expressed in the logoi is somehow
constructed from "Platonic elements" (in conjunction with some others, pre·
sumably un-Platonic). 31 ln Aristotle's hands, Plato's terms take on new
meanings, and his concepts may be entirely reevaluated. 32 For example,
Plato and Aristotle agree that power (6waµLç) means ability to enter into a
relation. But for Plato, being is power, that is, ability to affect or be affected
by another; Aristotle identifies being in the primary sense with actuality,
which may affect another but is never itself affected and so does not enter
into a relation properly speaking. 33 I will argue in chapter 1 that Plato and
Aristotle agree about art that it requires an extrinsic mover because it con·
tains no intrinsic principle of motion. But for Plato, nature is a work of art
because it can be so characterized, white Aristotle contrasts art and nature
precisely because nature does contain an intrinsic source of motion.
To find a Platonist in Aristotle, we would need, minimally, to find
him arguing a Platonic thesis. And in the Ph,sics such a thesis is not to be
found. lndeed, I shall argue below that in Ph,sics 2 the main thesis, that is,
that nature is an intrinsic principle of motion, directly opposes Plato's daim
that nature requires a source of motion outside itself, namely soul, white in
Ph,sics 7 the thesis that "everything moved is moved by another" directly
opposes Plato's definition of soul as self-moving motion. lndeed, Plato argues
that "everything moved is moved by another" in order to arrive at self
moving soul as the origin of ail motion in the world; Aristotle argues that
"everything moved is moved by another" in order to show that the self
mover, too, is moved by another and so cannot serve as the origin of ail mo
tion. Granting to each logos the integrity as an argument that prima facie it
requires, yields not a platonizing Aristotle, but an Aristotle explicitly
anti-Platonic.
The integrity of Aristotle's argument as presented by the logos bring us
to the second daim at work here: We must begin with the assumption that
each logos is a systematic argument-albeit with asides, unexpected obser
vations, or replies to objections that seem startling or out of place. These
asides and so on may be evidence of the oral origins of the logoi, but they do
not nullify the integrity of each logos as the treatment of a particular problem
within which Aristotle's arguments operate. Rather, the assumption should
go the other way: each logos, here those of the Ph,sics, far from being a patch
work of propositions from different periods, is a whole comprised of argu•
ments that, however many times they have been revised, exhibit internai
coherence as arguments. Likewise, the position articulated in the logos is not
a patchwork of elements from diverse historical origins but a systematic treat•
ment of the problem at hand. ln the chapters comprising part 1, I shall show
this assumption and its results at work: a remarkably coherent set of argu
ments in Ph,sics 2, 7, and 8.
8
Introduction
9
Arisrode's Physics and lts Mediewl Varieâes
10
Introduction
li
Aristode's Physics and lis MedietlCll Varieries
that is, whether as a moving cause or a final cause; the first mover is not the
proper subject of the argument and appears only as the last moment in the
resolution of an objection. The argument, defined in Plr:ysics 8.1, concerns
the etemity of motion in things, while the objection concerns what motion,
if any, can be eternal and continuous. This mover appears only as the cause
required to establish this etemal motion: eternal, continuous, circular loco
motion requires a mover that is unmoved, partless, indivisible, and without
magnitude. Arr, question about the first mover considered independently of
this relation at once violates the logic of Aristotle's argument and redefines
the problem at stalœ within the logos. 46
Here we find the remarkable etficiency and cogency of Aristotle's logos.
The rhetoric, logic, and domain of the arguments are remarbbly unified.
The appearance of the main thesis and its supporting argument first in the
logos dominates the arguments in ail three respects. And, as I shall argue, in
Plr:ysics 2, 7, and 8, Aristotle rarely violates this relation, that is, rarely says
more than is required fur the argument at band as defined by this structure
and its thesis. lndeed, critics of Aristotle's arguments often fail to notice the
limits placed on those arguments by this structure: it renders additional con
siderations of a subordinate problem irrelevant to the problem at band.
By establishing the thesis, logic, and domain of Aristotle's arguments,
the logos sets their exact limits insofar as they can be known with certainty
on the basis of the text. No doubt, an argument can both defend an earlier
thesis and represent independent commitments or beliefs, and it seems im
possible that Aristotle would not believe at least some of the daims made in
subordinate arguments. Hence the irresistible impulse on the part of bis read
ers to emancipate claims from subordinate arguments and treat them as topics
in their own right, independent of the thesis they serve within the logos.
But it is virtually never the case that a philosopher develops and uti
lizes all the implications of every daim at worlc. in a set of arguments. Posi
tions develop by establishing and then utilizing claims insofar as they are of
interest vis-à-vis the particular position. And Aristotle's position is defined
by, and systematically developed within, the thesis that appears at the open
ing of the logos. Hence, it is impossible to determine with certainty his philo
sophie commitments outside of this structure. lndeed, I would suggest that
any effort to determine Aristotle's philosophie commitments across the logoi
must always talc.e these definitions into account.
As we shall see with the Aristotelians, abstracting the first mover of
Plr:ysics 8.10 from its position within a resolution of an objection at once
changes the rhetoric, logic, and domain of the argument. lt emancipates the
argument of Plr,sics 8.10 from its subordinate role as the resolution of an ob
jection, presupposes a different logical structure fur the logos (and fur the
Plr:ysics generally), and gives Plr:ysics 8 new subject matter--God. While fur
Aristotle physics concerns things that are by nature, fur his medieval readers
12
God is often the proper subject of Plrysics 8 and through it of physics as a
science. In short, physics as a science is redefined both in itself, its structure
and subject matter, and in its relation to theology.
The legitimacy of such a shift cannot lie in the logical structure of the
logos or the problems (and solutions) of physics as Aristode defines them.
Rather-and I shall argue the specifics of this daim in the last four chap
ters-it lies in reorganizing the logical and rhetorical structure of Aristotle's
logos in light of new problems and new structures-those of the commentar
ies, or quaesâones, developed by medieval physicists. Perhaps we should iden
tify in the restructuring of Aristotle's logos a "mark" of the vitality of
philosophy: the logos gives us the limits of what can be defined as Aristotle's
position but does not give us the systematic limits of Aristotelianism.
Before tuming to Aristotelian physics, 1 must raise two cautionary
notes. First, 1 make no daims about the corpus as a whole or about a theory
of science of which the Plrysics might be considered a part. Because this study
considers the logos and its structure, systematic problems or issues across the
logoi will not, for the most part, be raised. ln this sense, this study constitutes
but a first step to understanding systematic issues as they may be construed
across the corpus. But if such construals are to bear any relation to their or
igins in Aristotle, it is a necessary step: establishing the structure and order
of Aristotle's arguments as they appear within the logos.
Second, my thesis about the structure of Aristotle's arguments requires
that those arguments be kept always in the forefront of my analysis. lt is im
possible to do so and to consider in the text of this study important contem
porary issues that have been raised conceming these arguments, without
creating an incomprehensible maze. Hence, with some exceptions, I have
relegated secondary sources to endnotes. There is a price to be paid for this
decision. The notes must both present primary sources and serve as the locus
of contemporary discussions. But finally the primary advantage of this deci
sion outweighs its disadvantages: by keeping Aristotle's logos as the primary
focus of my text, 1 practice the structural integrity that I argue is so important
for Aristotlc, namely, the subordination of ail subsequent arguments to the
thesis established by the logos.
13
Aristode's Physics and lrs Mediewil Varielies
Plrysics or using propositions from it, may be called "Aristotelian" in this re
spect without judging the substantive issues of the position itself or the
concepts at work in it. Thus in part 2, I consider commentaries on the Plrys
ics by Philoponus, Albert Magnus, and Thomas Aquinas, Quaesâones on the
Plrysics by Jean Buridan, and an important argument from Duns Scotus that
concerns place and utilizes propositions from the Plrysics. These Aristote
lians, I shall argue, radically restructure Aristotle's arguments, with striking
results first for problems and their solutions within physics and finally for
physics as a science.
As part 1 is committed to an analysis of three logoi from the Plrysics-
taking the logos as the immediate and primary unit of Aristotle's writing
and argumentation-so part 2 considers five important Aristotelians in the
immediate and primary units dictated by their analysis of the Plrysics. As
we shall see below, Aristotelians do not feel bound by the structure or logic
of Aristotle's logos. Hence, they use propositions from across the corpus.
Because the arguments of these Aristotelians form the primary subject of
part 2, 1 shall follow their excursions across Aristotle's arguments and texts,
even when these exceed the limits of Aristotle's own writing and of what
has been argued in part 1. lndeed, I shall argue that this very procedure
produces the coherence, integrity, and variety of positions that character
ize Aristotelianism. 48
Each of these Aristotelians redefines Aristotle's physics by moving the
Plrysics into a commentary, question, or problem of an entirely different
structure from that of the logos. The various structures of commentaries or
uses of Aristotle's writing have received little attention. 49 But these writings
exhibit remarbble differences, and, as I argue, these differences are not neu
tral to shifts in meaning. lndeed, they allow Aristotelians to redefine every
element of Aristotle's Physics: its rhetoric, its logic, the problems at stake in
it, and finally, the solutions to these problems.
The restructuring of Aristotle's Plrysics allows his commentators first to
redefine its arguments and then to combine problems from different logoi.
Furthermore, it enables them to introduce into their commentaries con
cepts entirely foreign to Aristotle-concepts originating in Stoicism, Neo
platonism, or even Christianity. Finally we find an array of different positions
called "Aristotelian."
These positions retum us to the problem of the coherence and integrity
of arguments deriving from different sources. For if, as I argue in part 1, Ar
istotle's theory of nature and motion rejects virtually every feature of Plato's
account in order to propose a quite different view of nature, then efforts to
combine concepts originating in Plato and Aristotle face difficult problems.
If the positions developed by these Aristotelians are to be coherent, then ei
ther concepts that are incompatible must be somehow brought together, or
one set of concepts must replace the other. 1 shall argue that in the Aristo-
Introduction
telians considered here, the latter is virtually always the case: The text may
be the text of Aristotle, but the concepts are the concepts of Stoics or Neo
plationists. As a consequence, virtually from its inception Aristotelianism is
marked by the presence of un-Aristotelian commitments operating within
constructive accounts or uses of Aristotle's physics.
As an intellectual phenomenon, Aristotelianism presents features and
interests that often differ not only from Aristotle's, but also from one an
other. Indeed, perhaps the only feature shared by ail Aristotelians is an abid
ing interest in the definitions, arguments, and conclusions found in the texts
of Aristotle. 50 After the death of Aristotle, these texts take the place of the
teacher and serve as the locus of Aristotelian physics. 51
The role of Aristotle's writing for Aristotelians cannot fail to affect the
status of the logos. For Aristotle, each logos is a relatively independent dis
cussion concerning a particular problem and bearing a close relation to oral
discussions in his school. Indeed, Aristotle may be thought of as establishing
this form of writing as such. 52 But early in Aristotelianism, the logoi become
fixed and are treated as authoritative. 53 Where Aristotle's logoi are focused on
problems, and no philosophie system transcending these problems is articu
lated in them, Aristotle's successors focus on the logoi and almost immedi
ately begin comparing and systematizing them. In short, the logoi become
definable as an ultimate source, an authority, for various views. 54
This shift in the status of the logoi, which is historical in its origins and
philosophie in its results, constitutes the first mark of Aristotelianism. As a
result of it, the logos is objectified, while at the same time the philosophie
commitments of the reader need not originate in, or even coincide with,
those of Aristotle or his school. 55 In this sense, the logoi become impersonal,
and Aristotle's readers philosophically anonymous. These points work to
gether to inform the textual tradition of Aristotelianism-a tradition pro
ducing an astonishing array of positions, ail of which are developed within
the context of Aristotle's writings.
The history of Aristotle's texts is a problem that lies beyond the scope
of this introduction. 56 But we do know that they were commented upon and
taught at the Neoplatonic Academy at Alexandria, and it is here, in a strong
sense, that Aristotelianism has its origins. 57 While the Neoplatonic school of
Athens was closed by the Christian emperor Justinian (or at least went into
a final decline) in 529, that of Alexandria reached an agreement with
Christianity.58 Minimally, this agreement could not but affect the emphasis
given to commentaries on Aristotle. Sorne, although not ail, members of the
school were Christians, including Philoponus, and formulated interpreta
tions of Aristotle that make him seem "close to Christianity."59
At Alexandria, "one major way of doing philosophy at this time was
by writing commentaries on Plato and Aristotle. "60 And indeed, extant
commentaries from this school are voluminous. But in their philosophie
15
Aristode's Physics and lts Medimil Varieâes
r6
Introduction
17
Arisrode's Physics and lts Mediewl Varieâes
arguments that motion in things must be etemal is, on this view, complete
afterAristotle's brief dismissal of the three objections against it. The remain
der of the argument sets out on a new and more important task: the proof of
a first mover. As a result, not only is the problem at stake in this book re
defined, but its rhetorical structure, its logical structure, and the domain of
its conclusions are shifted accordingly.
Rhetorically, the arguments progress to their goal rather than being
subordinated to an opening thesis. Logically, Aristode's single thesis, that
motion in things must be eternal, becomes an introductory argument, while
a second, more important argument begins at Plrysics 8.3 and reaches its con
clusion only with the closing line of Plrysics 8.10, the closing line of the Plrys
ics: that there must be a first mover, whom ail men call "God." In short, far
from being the narrowest and most specialized moment within physics as a
science, Plrysics 8.10 becomes the ultimate end of physics: a proof ofGod that
is at once the capstone of physics and a threshold to theology.
Like so many readers even now, Jean Buridan was profoundly influ
enced by Thomas's view of Plrysics 8, namely, that it is a proof of God. At
tributing it direcdy Aristotle, he asks if a proof ofGod is properly included
within the domain of physics and answers no, it is not. Hence, he rejects the
main thesis, as he understands it, of Plrysics 8. But this rejection does not, for
Buridan, imply rejecting Plrysics 8 as a whole. Rather, individual arguments
within the book interest him considerably-for example, "Aristotle's ac
count of projectile motion" in Plrysics 8.10. Consequendy, he emancipates
various arguments from any larger structure within Plrysics 8, and insofar as
they interest him, he analyzes, accepts, corrects, or rejects them. The sub
ordination ofAristotle's arguments to a primary thesis disappears, and the in
tegrity of the arguments in Buridan 's Quaestiones is entirely that of Buridan.
The same point may be made for Duns Scotus and his argument about
angels, presented in chapter 8, even though he is not writing a commentary
on the Plrysics. His overall argument is dominated by a single interest that is
theological in origin, and ail arguments within it, including those borrowed
fromAristotle's Plrysics, are put to work in the service of this interest. Thus,
propositions from Plrysics 7 and Plrysics 4 are moved directly into a theological
arena and put to work in an argument (and a text) designed to explain how
angels occupy place.
I argue throughout chapter 8 that Duns must develop a new concept of
place to solve a theological problem about angels and, ultimately, God. The
problem is made more complex by the presence of a voice of authority, Duns's
reference to Tempier and the Condemnation of 1277. By radically emanci
pating Aristode's definition of place from both the problem it is designed to
solve and its supporting arguments in the Plrysics, Duns is able to use this defi
nition entirely for his own ends. Indeed, Duns's assertion of this definition
stripped of virtually ail its relations to the Plrysics seems to echo Tempier's
r8
Condemnation-a definition asserted without support appears as reason's
version of a decree. Duns's definition of the problem of place, and the eman
cipation of Aristotle's definition of place from its context in his physics, yield
a position that seems, at least in some respects, peculiarly modern.
These varieties of Aristotelianism raise two questions important for the
history of ideas and for the very conception of science and philosophy more
generally. The first question is substantive. Within Aristotelianism, how do
these shifts in the structure of Aristotle's arguments affect the arguments sub
stantively? As I have indicated here and argue throughout part 2, Aristotle's
arguments are entirely redefined.
The second question concerns the relation of Aristotelianism to Aris
totle. How can we account for the unity and consistency of Aristotelian
physics, on the one hand, and its extraordinary variety and vitality, on the
other? The varieties of Aristotelianism, each with its own integrity, indicate
that in Aristotelianism we find neither the decline of Aristotle's physics nor
a graduai articulation of the inadequacies or contradictions inherent in it.
Rather, we find in Aristotelian physics a progressive redefinition of the prob
lems at stake for physics and philosophy, along with a correlative reworking
of the arguments that solve these problems. The redefinition of the problems
of physics is part and parcel of the rearticulation of Aristotle's arguments
within the logical and rhetorical forms of Aristotelians. lndeed, although the
words may be the same, the Plrysics as a text is rewritten when its arguments
are no longer subordinated to an opening thesis but form a hierarchy, progress
to a conclusion, and are treated as independent of one another or put to work
in order to solve a theological problem. The coherence and integrity of the
logos are replaced by the coherence and integrity of other forms of writing,
and with them other conceptions of physics, its logic, problems, and work as
a science.
19
Part I
Aristotle's Physics
Chapter 1
23
Aristode's Physics and lts Mediewl Varieties
reveals what, for Aristode, is the most important competing account of na
ture and the relation of matter to form. By eliminating this competing ac
count at the outset, Aristotle can focus exclusively on the requirements of his
own definition of nature. (3) Aristotle rejects materialism and twice inter
prets an odd image, a planted bed that acquires the power to send up a
shoot. 7 I shall consider these issues in order and argue that Plrysics 2.1 es
tablishes the problems that form the proper subject matter of the remainder
of the Plrysics.
( 1) Aristotle opens Plrysics 2 by contrasting things that are "by nature" with
those that are "by art." The former, consisting of animais, plants, their parts,
and the four elements (earth, air, fire, water), contain an innate principle of
motion, while the latter do not. 8 That is, insofar as a thing is a work of art,
such as a bed or coat, it possesses no innate impulse to change; but insofar as
such artifacts are made from things that are by nature (e.g., stone or earth),
they do possess such an impulse. 9 For example, earth is by definition heavy
and so by definition goes downward. Therefore, an artifact made of earth is
also heavy and goes downward-not by virtue of its artistic form, but by vir
tue of the natural element from which it is made. 10
This relation indicates "that nature is some source and cause of being
moved and being at rest in that to which it belongs primarily, in vir tue of
itself and not accidentally." 11 This formulation spells out the characterization
of nature as "a principle of motion" and reveals the problems entailed by it
that are addressed in the remaining books of the Plrysics.
The first and most obvious problem concerns the relation between na
ture and motion. It is made explicit in the opening lines of Plrysics 3.1: if the
meaning of "motion" were unknown, nature too would remain unknown;
and if we are to understand motion, we must also consider those "terms"
without which motion seems to be impossible, such as the continuous, the in
finir.e, place, wid, and time. 12
Secondly, there are the principles "of being moved and of being at
rest." The principle of being moved will ultimately require Aristotle both to
define motion as the actualization of the potential qua potential (by that
which is actual) and to establish the principle that "everything moved is
moved by another." 13 The principle of being at rest is "contrary to motion"
in that which is movable and is associated with the related problems of ele
mental motion and natural place. 14
In short, Aristotle establishes his definition of nature first, sharply con
trasting it with art, and then proceeds to particular problems, implications,
and supporting arguments entailed by this definition. Hence "nature,'' or "by
nature,'' is both the first and the most important topic of Plrysics 2-and ul
timately of the Plrysics as a whole. 15 If we look at the rubric of Plrysics 2 as a
logos, the force of nature as a tapie emerges.
Arisrode's Definition of Nature
Plrysics 2.1 defines nature and things that are "by nature." Aristotle
then distinguishes mathematics, physics, and astronomy by distinguishing
among their subject matters: physics deals with things that are "by nature"
and so considers things that (and insofar as they) involve both form and mat
ter-matter, that, unlike the matter of the heavens, can be generated and
corrupted. 16 The argument then proceeds by stages to the four causes that
are by nature, to chance and spontaneity, which might be thought (falsely)
to be causes "by nature" in addition to the four causes, to the relation of
final and formai causes within nature, to the sense in which nature is a cause
that acts for the sake of something, and, finally, to necessity and its place
within physics.
In effect, the logos begins with a bang ("Of things that are, some are by
nature and some are from other causes") and proceeds through a series of pro
gressively more specialized problems to end with a whimper-hypothetical
necessity in nature and its identification with matter. 17 Aristotle first estab
lishes what is most important and then turns to whatever topics are necessary
for its clarification or further support. In this sense, the arguments in Plrysics
2, as in the remaining books of the Plrysics, are neither progressive nor cu
mulative. Rather they become narrower and more specialized in support of
an opening thesis or definition. 18
And in Plrysics 2 the primary thesis concerns things that are by na
ture, that they contain "a source of being moved and of being at rest in
that to which it belongs primarily." ln Plrysics 2.1, Aristotle makes two
points about nature and things that are "by nature." (1) Nature is a sub
stance, a subject, and, although in a secondary way it may be identified
with matter, it is primarily identified with form and shape. 19 Form is what a
thing is when it has attained fulfillment, form is the proper object of the def
inition, and form is reproduced by nature-man begets man. 20 Form in the
sense of shape is what a natural thing attains when it is fully developed. 21 A
natural thing is in the fullest sense when it has completely attained its form;
and we know that thing most completely when we know its form, because to
know a thing's form is to know its definition. Therefore, nature is primarily
identified with form.
But this identification leaves Aristotle with something of a dilemma:
he intends to distinguish things that are by nature from those that are by
art; but art, too, is primarily identified with form-there is nothing artistic
about a thing if it is a bed only potentially but has not yet received the form
of a bed. 22 As form, nature and art are alike. Thus, the identification of na
ture with form does not sufficiently specify it so as to distinguish nature from
art. (Aristotle does not mention god in Plrysics 2, but we may note that it is
pure form, and so the identification of nature with form fails to distinguish it
from god as well as from art.) 23 We require Aristotle's second characteristic
of nature.
Aristode's Physics and lts Medieval Varieâes
(2) Nature is not just furm: things that are by nature have an in
trinsic impulse of change. That is, things that are by nature possess an ac
tive orientation toward their final furm. 24 ln this sense, natural things are
unlike artistic things, because artifacts possess no such innate impulse. 25
This innate impulse of change serves as the principle of being moved speci
fied in the definition of things that are by nature; it rounds the sense in which
natural things include matter and, so, accounts fur why, as Aristode goes on
to explain in Plrysics 2.2, things that are by nature must refer to matter in
their definition. 26
Here we reach a key issue: fur Aristode, in natural things to be moved
does not imply a passive principle. Matter (or potential), which is moved by
furm (or actuality), is moved precisely because it is never neutral to its
mover: matter is aimed at-it runs after-furm. 27 Because of the active ori
entation of the moved toward its mover, no third cause is required to combine
matter and furm. They go together naturally: furm constitutes a thing as nat
ural, and matter is aimed at furm.
ln short, then, nature requires both that furm immediately constitute
the natural thing and that matter relate intrinsically to furm. lndeed, in nat
ural things, matter cannot exist prior to, or apart from, furm; so flesh can
neither corne to be nor endure apart from a living animal: a severed hand is
a hand in name only. 28 And so, Aristode concludes, the combination of
furm and matter, such as a man, is not "nature" but "by nature."29 And so,
too, are plants, animais, their parts, and the fuur elements. 30
(2) The sharp contrast of nature with art here reveals Aristode's interest in
refuting the view that identifies nature with art-Plato's view. An account of
nature as a complex work of art furmed by a master craftsman who looks to
an eternal mode( and instantiates that model onto chaos, insofar as chaos
can receive it, occupies Plato's Timaew and is consistent with arguments in
other dialogues. When Aristode defines nature as an intrinsic source of being
moved, he not only establishes the subordinate problems occupying the re
mainder of the Physics, he also rejects virtually every feature of Plato's ac
count. This rejection at the outset enable him to pursue his own account
more fully in the remainder of the book.
Plato's account establishes the physical world as caused from without.
The Demiurgos produces the physical world as an artisan produces the prod
ucts of his craft: he looks toward a model, or pattern, to instantiate it on his
effect. 31 The Demiurgos orders the world-itself an artifact halfway between
the random, resistant chaos of the receptacle and the being of the furms-by
sending soul down into resistant chaos so as to produce the world. 32 Soul is
the messenger of the gods, bringing order down into things and reporting the
needs of things to the gods. 33 ln this sense, like the Demiurgos, it operates not
as an intrinsic, but as an extrinsic, source of motion. Befure turning to Plato's
Aristode's Definiâan of Nature
27
Arisrode's Physics and lts Medieval Varieries
and Plato's account of nature along with the pointed rejection of the doctor
curing himself as an example of self-moving motion.
(3) But Plrysics 2.1 does not end with the rejection of a self-mover. Having
eliminated the most obvious case of the self-mover, Aristotle goes on to con
sider the position of those who would identify nature with
Again, he intends to reject his opponents' view while at the same time es
tablishing his own position as the primary thesis to be considered. Aristotle
in effect situates his definition of nature as distinct from (and superior to)
what he takes to be its two most serious competitors, Plato's account of the
physical world and the materialists' account. l shall suggest that in a broader
sense, his argument against the materialists reveals a full vision of the Greek
context in which he works and the ultimate origin of the problem concerning
the relation between art and nature.
After suggesting that nature can be identified with matter, that is, the
immediate constituent taken by itself without arrangement, Aristotle inserts
a puzzling argument:
Aristotle returns to this peculiar example a page later at the end of his ar
gument, and here he refers to the argument generally as if it were a "sign"
that is well known:
And therefore they say that the figure is not the nature, but the
wood is, because if the bed were to sprout, not a bed but wood
would come up. 54
29
Arisrode's Physics and lrs Mediewl Varieda
even further, and ail things could be reduced to the four elements: "for ex
ample, bronze and gold to water, bones and wood to earth, and likewise for
other such."55 On this materialist view, there is no real difference between
natural form and artistic form, because both are like accidents added to, and
ultimately separable from, matter.56
Without explicitly rejecting this view, Aristotle moves to the argu
ment that "nature" is the shape or form of a thing given in the definition.57
And here, as we have seen, art and nature are both identified with form.
Both a potential bed and potential flesh must receive form before they can
be said to be "by art" or "by nature.''58 But then he adds the key point:
"nature" is in this sense identified with "the shape, namely the form, (not
separable except in definition) of things having in themselves a source of
motion. "59 That is-and for Aristotle the crucial difference between art
and nature lies here-when a thing is "by nature,'' the form, which consti
tutes what it is actually and by definition, is not separable in fact from the
matter, which is the thing's source of being moved, because matter is aimed
at form.60
Aristotle now explicitly rejects the materialist view and asserts that in
deed nature is form. He returns to the "sign" of the planted bed, which now
signifies something rather different from what it signified for Antiphon.61
Again Aristotle says, "Man cornes to be from man, but not bed from bed."62
The figure is not the nature of the bed in the same sense that the form is the
nature of a man, because if you planted a bed and it could sprout, it would
sprout wood and not more bed. Here rather different conclusions follow about
the planted bed and the relation between nature and art.
When we define an object such as a bed as an artifact, the olive wood
out of which it is made is no longer central to the definition. The definition
of any artifact must bear upon its artistic form (e.g., bed) as imposed by an
artist and not its matter and natural form (e.g., the olive wood out of which
it is made). Hence, in an artifact, what is by nature is its matter in relation
to its form; but what makes it to be definable as an artistic thing is the form
imposed upon it by the artist.63 Therefore, olive wood can simultaneously be
both wood and a wooden bed. The relation between art and nature, as Ar
istotle would have it, requires that an artifact such as a bed be identified both
with its olive wood (i.e., the combination of form and matter that, if pos
sible, would "by nature" grow) and with its artistic form, the extrinsic shape
imposed by an artist and the object of the definition of the thing as a work
of art.
These distinctions show how an artifact is properly identified both with
what it is by nature, its matter in relation to natural form, and with its ar
tistic form. On the one hand, Aristotle maintains the primacy of form in any
object, artistic or natural. Ail objects, whether "by nature" or "by art," pos
sess their names and.br definitions in virtue of form. On the other band, he
30
Arisrode's Definition of Nature
31
Aristode's Physics and lts Mediewl Varieties
The olive tree in Greelc literature is often associated with divine pres•
ence and longevity, and a marriage bed that retains its identity with a rooted
olive tree would retain this identification as well. 69 Consequendy, in order to
be the bed of Odysseus, the bed cannot lose its identity with the rooted olive
tree, that is, with what it is by nature, on Aristode's account. 70
But as the artist, Odysseus plots out the bedroom and the bed itself
around the olive tree from which he will form the marriage bed. What malces
the bed unique as a bed is Odysseus's artistry in shaping the bedpost "from
the roots up." And herein lies, as Aristode would have it, its artistic form.
The artistry lies in the bed being made by Odysseus so as to be immovable.
lts immovability both malces the bed formally unique and explains the con•
struction of the bed, that is, why the bedpost retains its identity as the rooted
trunlc of a tree.
The unity of form and matter in this sign, this immovable rooted bed,
cannot be overemphasized. 71 A tree is by nature rooted and immovable. The
olive is associated with divine presence and longevity. But beds are normally
made of "lumber," the wood sawn from a tree that has been eut down. Qd.
ysseus malces his bed immovable, and this immovability, both present in the
olive tree as rooted and imposed upon the bed through the unique decision
and construction by Odysseus, constitutes the crux of Penelope's test-her
search for a clear sign. Only this unity of art and nature makes the bed op·
erate as a sign absolutely clear between husband and wife.
With the perfect unity of art and nature, the sign of the bed in Homer's
Odyssey functions perfectly within the plot of the poem and completes the
return of Odysseus. The immovable bed, to which Odysseus and Penelope
immediately retire, stands as a tolcen of perfect marriage. While Odysseus has
rejected even immortality in order to return home to his wife, Penelope has
withstood the infamous siege of the suitors. 72 Her test possesses a double
edge: the immovability of the bed tests not only Odysseus's identity, but also
Penelope's faithfulness. If the bed were moved, the secret sign of the marriage
would be destroyed: the bed would be the bed of an adulteress. No other
woman could lcnow the secret of the bed and so formulate this test; Penelope
would not use her lcnowledge of the bed in such a test except as a faithful wife.
While only Odysseus could not mistalce the sign of the bed, only faithful
Penelope could use this sign as a test. Thus, the rooted bed constitutes a sign
excluding everyone but Odysseus and Penelope, returning husband and
faithful wife. The sign of the bed signifies the sanctity and inviolability of
their relation. 73 The formai perfection of this marriage is signified by a bed
made from a rooted olive tree: mortals in a divine union.
lt may be well to note that talcing our due from Aristotle solves two
serious problems traditionally associated with the sign of the bed in Homer.
The first concerns Odysseus's anger when Penelope tells Eurylcleia to move
the bed: "For the first time in the whole Odyssey, Odysseus is mastered by a
32
Aristotle's Definition of Nature
sudden impulse [i.e., his anger]. Odysseus speaks without perceiving the im
plications of his interlocutor's words."74 What Odysseus does not know is that
Penelope's words constitute a test. He most surely understands the implica
tions of Penelope's command to Eurykleia. While he has given up immor•
tality itself to return to her, Penelope's command to move the bed implies
that she has been unfaithful. Odysseus's anger is both completely justified on
the basis of Penelope's command and immediately resolved at the revelation
of the test and the truth of the sign on which is rests.75
Secondly, the hed of Odysseus seems curious.76 Stanford suggests that
the olive tree might have been sacred but would then scarcely have been
proper matter for a marriage bed, and suggests that natives of the interior
of New Guinea, whose traditions go back to Neolithic times, do not com•
pletely dear their gardens, hecause of the difficulty of felling a tree with
a stone tool.77 Such an explanation misses the point of Odysseus's bed as
a unique union of art and nature: Odysseus male.es the hed to be rooted from
the olive around which he designs the room. (Surely, anyone who cuts down
suitors as Odysseus does could handle a tree!) The answer to the curiosity of
the bed lies with the special nature of the marriage of Odysseus and Pene
lope, especially if we think of other couples in Homer or Greek mythology
more generally.
Aristotle does not mention Homer in Physics 2; nevertheless, his treat·
ment of the "planted bed" as a common sign, and his reinterpretation of it,
constitute a strong due as to its importance. And that due works together
with the other features of Physics 2.1 to define for us Aristotle's specific in
terests in defining nature and contrasting it with art.
His immediate interest in defining nature is to establish his definition
in contrast to those opponents whom he takes to represent the most serious
challenges to his position. And these opponents are Plato, for whom nature
is a work of art, and the materialists, for whom nature and art alike are at·
tributes added to the real nature of a thing, namely, its matter. The ultimate
background to the entire argument about nature, art, and their relation may
rest with one of the most remarkable symbols of ail Greek literature, the
planted bed of Odysseus. And Aristotle dearly thinks that his distinctions
account for this symhol hetter than do those of his opponents. Hence his po·
sition is the best, and his definition of nature (and its relation to art) is es
tablished and ready to be explored.
What has Aristotle accomplished by the end of Physics 2.1? ln one
sense, a good deal. he has implicitly rejected Plato's account of nature, and
he has explicitly rejected the inadequacies of materialism. He has also rein
terpreted the sign of the planted bed and so shown the superiority of his po·
sition. And he has achieved these ends in the context of asserting his own
definition of nature and its two essential features, the primacy of form and
the innate impulse to be moved in things that are "by nature."
33
Aristode's Physics and les Mediewl Varielies
34
Chapter 2
35
Aristotle's Physics and lts Medieval Varieiies
to a special case of one thing being moved by another, thereby explicitly re
jecting Plato's soul as the origin of ail motion.
The second argument, that the series of moved movers cannot go on to
infinity, is directed against the atomists, perhaps Democritus, for whom there
is no need to seek a first cause, or origin, of ail motion. Thus, when Aristotle
concludes that there must be a first mover and a first moved, his position is
defined historically between the infinite and random motion defined by the
atomists and Plato's daim that the self-mover originates ail motion.
Within this historical framework, I shall argue that substantively this
argument concerns motion in a whole of parts. Aristotle considers only the
whole as such and excludes direct consideration of the parts. So for example,
he asserts that the self-mover must be divisible into parts but specifies neither
what these parts are nor their relations to one another. Consequently, the
argument of Plrysics 7 concerns only the self-mover and its motion as a whole.
The sharp focus on motion in a whole of parts both provides the strict con
ceptual domain of the argument and accounts for its apparent obscurity.
Indeed, the apparent obscurity of Plrysics 7 stems from a failure to no
tice this formai limit. As a consequence, readers from Simplicius to Ross im
port questions about the relation of the parts to one another within the
whole. But the absence of answers to such questions is not a failure; rather,
it results from the strict definition c:J the subject matter of the argument. I
shall argue that given this definition, these arguments are valid and
complete.
Finally, by briefly comparing the arguments of Plrysics 7 with those of
Plrysics 8 and Meraplrysics 12, I shall suggest that Plr,sics 7 serves a unique
purpose within Aristotle's more general account of motion in things. While
in Plrysics 7 Aristotle considers motion in a whole of parts, in Plr,sics 8 he
considers motion in things according to his definition of it as an actualiza
tion, and in Meraplrysics 12 he turns to substance.7 Thus, although the con
clusions of the three arguments look alike insofar as each proves that
"everything moved must be moved by another such that there must be a first
mover," in fact each utilizes different concepts and bears upon movers and
moved things in a different respect. Therefore, the domains of their respec
tive conclusions also differ, with the result that each argument is at least par
tially independent of the others. Finally, because the problems concerning
substance (Meraplrysics 12), concerning motion according to its definition
(Plr,sics 8), and concerning motion in a whole of parts (Plrysics 7.1) remain
distinct for Aristotle, he requires an independent argument for each problem.
Plrysics 7 alone considers motion in a whole of parts; hence, it occupies a
unique place in Aristotle's physics and solves a different problem than do the
arguments of either Plr,sics 8 or Meraplrysics 12.
My analysis of Plrysics 7.1 (and the opening sentence of Plrysics 7.2)
consists of four parts. The first two consider the basic formai argument: ev-
Parts, Wholes, and Motion
37
Arisrode's Physics and lu Medieval Varieûes
Several important issues appear here and are crucial to the subsequent
argument. Aristotle takes the self-mover to be moved essentially, that is,
"through the whole" (&à TO olcw), and not to be moved by something ex
trinsic to it. The self-mover can be rnoved either intrinsically and essentially,
or by something external to it. As moved intrinsically it must be in motion
as a whole. What does this assertion entail, and what is at stake in it for the
larger argument?
An important example of a self-rnover appears in the De Anima and
reveals the force of this notion of "intrinsic motion through the whole."17 As
a self-mover, a sailor is in motion both accidentally insofar as ail bis parts are
being carried by the ship, which is an extrinsic mover, and essentially, insofar
as he walks across the deck of bis ship. ln Plrysics 7 .1, Aristode unambigu•
ously specifies the argument: the self-mover undergoes neither accidentai nor
extrinsically produced motion, but essential intrinsically produced motion
the sailor as walking on deck, not as being carried by bis ship.
The self-mover (e.g., the sailor) is composed of two parts, soul and
body; but neither part can properly be said to be self-moving. Rather, the
whole composed of both soul and body moves so that only as a whole is the
sailor self-moving. For example, when a sailor walks, he soul does not remain
in the helm while bis body proceeds to the stem; both parts, soul and body,
move because both are parts of the whole, which moves as a whole.
Here is the crucial point for Plrysics 7.1: as a self-mover the sailor must
move as a whole, but we do not immediately know which part is the mover
does soul move body, or does body move soul? Likewise we do not know
Parts, Wholes, and Modon
which part is the moved-is soul moved by body, or is body moved by soul?
Further analysis would answer these questions. (And we shall consider this
problem in a moment, as it is central to the criticisms traditionally raised
against this argument.) But such analysis is not, strictly speaking, required
for the point at issue here: a self-moving whole, such as a sailor, is self
moving only as a whole, and it must be moved by something, even if we
cannot immediately identify what that something is. And this point alone is
the point to be proven.
ln Plrysics 7, Aristotle does not pursue the question of which parts of
the self-mover are movers and which are moved. And he gives the reason
why: for the present argument it is necessary to show only that the whole of
parts is moved by something. The argument is an argument that everything
moved is moved by something, and this fact ultimately implies that there
must be a first mover. This thesis, as established in Plrysics 7.1, 1 shall argue,
is the single thesis of Plrysics 7.
We see here the first and most serious formai determination of the ar
gument. Aristotle is not explicitly considering the relation obtaining be
tween mover and moved parts within a self-mover and he will not explain
how motion occurs, or even why, because such questions follow only upon
consideration of this relation. Such relations and their consequences fall out•
side the formai structure of this argument.
The argument continues. Given that any self-mover is by definition in
motion as a whole, Aristotle now argues that the motion of the whole de
pends upon the motion of the parts. ln this sense, namely, that the whole is
moved by the parts, the self-mover, too, is moved by something.
Any self-moving whole AB must be divisible; so let AB be divided at
C, so we have A C B. 18 If CB is not in motion, AC may (or
may not) be in motion, but AB cannot be in motion essentially and primar
ily. Why not? Because, as we see in the example of the sailor, the self-mover,
when it moves essentially, must be in motion through the whole.
And Aristotle now concludes his argument:
The motion of the whole depends upon its parts in the sense that if the parts
are not moving, the whole as a whole is not in motion. And consequently,
the whole as a whole may be said to be moved by its parts. Hence, the self
mover, too, is moved by something.
Aristotle has now established the first premise of his larger argument:
everything moved is moved by something. Ali things in motion are moved
39
Aristode's Physics and lts Medieool Varieâes
As bis final words indicate, Ross assumes that the parts cannot be of equal
status within the whole. Therefore, one part, presumably soul, must be su
perior, while another, presumably body, must be inferior; on Ross's assump·
tion, the motion of the whole cannot depend equally upon both parts, which
the argument requires, and, Ross concludes, Aristode is mistaken.
But in Plrysics 7.1, Aristode does not subordinate the parts to one an·
other, as Ross presupposes. ln fact, as we have seen, Aristode assumes only
that the motion of the whole AB depends upon the motion of the parts, AC
and CB. The divisibility of the mobile thing assumes only that ail the parts
belong to the same whole while indicating nothing about the individual
parts or their relation to one another. Within this argument, there is no way
to distinguish between parts that in themselves may be either material or im•
material, such as a leg and a soul; hence, ail the parts function equally within
the whole, and the question of their relations to one another independently
of the whole (or even within the whole) never arises and need not be ad
dressed. Indeed, strictly speaking, it cannot be addressed.
Ross apparendy expects a proof of a first mover based on soul's defini•
tion as a mover and body's as a moved; Simplicius expects a refutation of
Plato's doctrine of soul as self-identical mover originating ail physical motion
by its presence to body, and so he seems puzzled to find material relations that
he takes to involve extension. Hence, both Simplicius and Ross find this ar•
gument wanting and prefer the proof of Plrysics 8. But the argument of Plrysics
7.1 that everything moved is moved by something is bath anti-Platonic in•
sofar as it rejects the self-mover as an independent originator of ail motion
and based on material relations insofar as, for Aristode, soul accidentally en
ters into material relations by virtue of its location within body.
The argument of Plrysics 7.1 operates within the conceptual frame
work of a divisible mobile whole in which the parts are not distinguished
from one another. Aristotle shows only that the self-mover, too, is moved by
another-not how, by what, or why it is moved. Within this formai limit,
43
Aristode's Physics and lts Medieval Varieâes
44
Parts, Wholes, and Moâon
B. Each member of the series has a motion that can be taken sep
arately (242a27).
Each motion is from something to something and is not infinite
in respect of its extreme points (242a30).
Therefure, each motion is numerically one (242a30).
45
Aristode's Physics and lts Mtdieval Varieries
Any moved mover within the infinite series can be selected at random and
considered individually. Considered in itself, each mover (e.g., the hand
moving a staff) moves from here to there. Hence, the motion of each moved
mover is finite ip the sense of having definite extremes (i.e., from point X to
point Y). As definite in its extremes, the motion of each moved mover must
be numerically one.53
C. Because it has definite extremes and is numerically one, each motion OC·
cupies a finite time, as, again, when something moves from point X to point
Y.54 lt follows that "the motion of A being finite, also the time will be
finite."55 Thus, taken individually each moved mover in the infinite series
has a motion that, insofur as it is numerically one, moves from here to there
and 50 occupies a finite time.
D. Having established that the local motion from point A to point B takes
place in a finite time, Aristotle must now establish that the series of moved
movers exhibits an infinite motion. The argument occupies but a single sen•
tence; 1 give here the Oxford translation, since it is the one necessary for the
objection that follows. 1 shall suggest an alternative translation in a moment.
Parts, Wholes, and Motion
But since the movers and the things moved are infinite, the mo
tion, EFGH, i.e., the motion that is composed of ail the indi
vidual motions, must be infinite. 56
The assumption that the movers and things moved are infinite is contained
in the assumption of an infinite series of moved movers, and Aristotle pro
ceeds immediately from this assumption to the conclusion that the motion of
the whole series must be infinite.
But at first glance, the conclusion-that there is an infinite motion
composed of ail the individual motions-appears problematic. Ross daims
that the argument is invalid.
Aristotle surely seems to be in trouble. He has just argued that each moved
mover moves from point X to point Y in a finite period of time. If he requires
a new motion, some motion of a new whole composed of the individual mo
tions of the members in the series, then he must give an independent ground
for it, because it does not follow from the assumption of an infinite series of
moved movers. What is this motion EFGH, and is it legitimate to introduce
here a single motion "composed" of the individual motions of the moved
movers?
Part of the difficulty concerning a "composed motion" lies in Aristo·
tle's language itself. The text reads: ÈltEi. ôit wtELpa 'tà ICLVOÛVta acal. 'tà
ICLV01JI.LEV«, acal. 'ij KL'VTIOLi; 'ij EZH8 'ij È; éutaoCÎ>v wtELpoi; ËO'tm·. 58 A
more literai translation is this: "And since the movers and the things moved
are infinite, also the motion EZH8 of ail of them will be infinite." Obvi
ously, the problem involves the precise meaning of the phrase "of ail of
them" ( È; wmoCÎ>v).
If the phrase "Ès éutaoCÎ>v" introduces a "composed" (i.e., new) mo
tion, then Ross's objection would be obvious, and we should find it elsewhere
in the history of the argument. ln point of fact it is not to be found. Simpl·
icius simply repeats Aristotle's phrase with a minor expansion: 'ij Ès wtaaCÎ>v
wtELpoV ÔV't(J)V ËO'taL. 59 "The [motion] of ail beings will be infinite."
Thomas reflects the same understanding in "motus omnium qui est 'Esr,8'."60
In modern criticism the same view is reflected in Apostle's translation, "The
entire motion of ail of them which is PQRS . . . will also be infinite."61
ln fact, "Ès wtaoCÎ>v" here must simply mean serial motion. A series
contains an infinite number of moved movers such that each is moved by the
prior moved mover while itself moving the succeeding moved mover; and it
47
Arisrotle's Physics and lis Medieval Varieries
can be considered as just that: a series. ln a simple series, such as the motion
of an arm that moves a hand that moves a staff, each member, the arm, the
hand, and the staff, can be considered separately, or their motion (i.e., the
motion of ail of them) can be considered serially. That the moved movers
form such a series is implicit in the assumption that each is both a mover and
a moved. Consequently, it follows both that each moved mover exhibits a
finite motion from point A to point 8 and that if the series of moved movers
is infinite, it would as a series exhibit an infinite motion.
This reading of "the motion of ail of them" renders the phrase consis
tent with the initial assumption, an infinite series, made for the sake of the
reductio argument. Furthermore, it is consistent with the formai limits of the
initial argument of Plr:,sics 7 that everything moved is moved by something.
That is, "the motion of ail of them" represents a whole of parts within which
each part is equivalent to every other part. And in this sense, the series of
moved movers constitutes a whole of undifferentiated parts and adds nothing
new to the initial assumption of an infinite series of moved movers. Aristotle
does not justify the phrase (È� imaaœv) because it adds nothing new to the
argument. lt merely refers to the assumption (for the sake of this reductio
argument) of an infinite series of moved movers.
ln the formai structure of the argument, nothing is required beyond the
assumption of an infinite series of moved movers with which the reductio
argument begins. lndeed, the argument is developed strictly on the basis of
its initial assumption. If we assume an infinite series of moved movers, then
(we must also assume that) the motion of ail of them will be infinite. Later
in the argument, Aristode specifies that the members of the series are united
through touching or continuity; 1 shall argue at that point that these con
cepts, too, are implicit in the assumption of a series of moved movers.
E. The next moment of the argument is hardly more than a corollary about
the infinite motion of the whole. Aristotle now adds that this motion must
be infinite regardless of whether the motions ci the individual members of
the series are equal to or greater than one another.62 One can imagine, for
example, an infinite series of toothed gears of different sizes, each moving the
next and being moved by its predecessor. Differences in the distances tra
versed by the moved movers (e.g., the different-size gears) obviously do not
affect the infinity of the motion of the whole series. This point concludes the
argument that the motion EFGH must be infinite.
These two arguments follow immediately from what has been established.
F. (1) The motions of A and of the other moved movers are si•
multaneous. This premise derives directly from the hypothesis
with which the reductio argument opens.
(2) There is an infinite motion of the series of moved movers.
This premise has just been established (at D).
Therefore, the infinite motion of the series of moved movers
occupies the same time as the motion of A. That this conclusion
follows from the two premises is obvious.
Finally,
This conclusion reaches the contradiction necessary to show that there can•
not be an infinite series of moved movers. The reductio ad absurdum argu•
ment seems complete, and the conclusion that there cannot be an infinite
series of moved movers, but there must be a first mover, seems to follow.
The conclusion that there must be a first mover seems to follow, but
Aristotle raises an objection that he say s must be addressed before the argu•
ment is in fact complete. 64 lt is obvious, he daims, that an infinite motion
of a single thing cannot occupy a finite time; but an infinite number of in
dividually completed motions can without contradiction occupy a finite
time. ln order to compleœ the reductio argument, Aristotle must show that
the infinite series of moved movers is sufficiently unified to constitute a single
moved thing (and motion) rather than an infinite number of individuals and
49
Arisrode's Physics and lrs Medieval Variecies
50
Paru, Wholes, and Motion
two moved movers and their motion one.) When things touch one another,
not only are they in succession, such that one comes after the other, but their
extremities are together, that is, in one place. 71
When one thing is in succession to another, something of the same
kind cannot intervene, but something of a different kind might. For exam
ple, one apple is in succession to another so long as no third apple intervenes
between them; but something else, such as place, can intervene without af
fecting the fact of succession. But when things touch, nothing, whether of
like kind or different, intervenes between them, because their extremities oc
cupy the same place.72 When two apples touch, their extremities are to
gether, such that nothing, neither another apple nor even "empty" place,
can intervene between them.
Conânuil)l As touching presupposes succession but is a stronger con
dition, so continuity presupposes touching but is a yet stronger condition be
tween the members of the series. lndeed, it is the strongest condition found
in the formation of a series. T wo things are continuous when their limits,
which are touching, "become the same and one. "73 Aristotle emphasizes this
point, adding that continuity is impossible if the extremities are two. 74 So,
for example, two lines become continuous if their extremities are con
nected-at which point there is only one line. ln its local context, this point
is crucial for the following argument concerning what makes a motion one:
continuity is one of the essential characteristics of a motion that is one pro
perly speaking. 75
With these meanings for touching, succession, and continuity, we can
return to Plr,sia 7.1. Assuming an infinite series of moved movers, an infi
nite motion would take place in a finite time, which is impossible; but if
there were an infinite number of individually completed motions, no con
tradiction would result. The series must in some sense be one, so that there
is one infinite motion rather than an infinite number of individual motions.
Aristotle replies that, as we see to be universally the case, wherever one thing
is moved locally by another, mover and moved are in contact or continuous,
so that mover and moved together form some one.76
Touching unites the moved movers by making their extremities one in
place, while continuity unites them in the stronger sense of making the ex
tremities one and the same. Both touching and continuity make the series of
moved movers "some one": if extremities are in the same place, or if they are
one and the same, then it would be impossible for one member of the series
to move without the next member being moved as well. And so on through
the series. ln short, either continuity or touching is sufficient to make the
series of moved movers function as a whole of parts that is in motion essen
tially and through the whole; that is, no part can remain at rest white the
others move.77 Each must be moved by its predecessor and must move its
successor.
51
Aristode's Physics and lts Mediewl Varieties
Here is the sense in which the motion of the series of moved movers is
one: as a whole of parts in motion essentially. Clearly, succession fails to
make a series one: when one thing is merely in succession to another, one
can move without the other being moved. Touching, such as a hand touch
ing a staff, is the weakest relation, while continuity, as in the arm from elbow
to wrist, is the strongest relation that can unify the members of the series.
Only by touching or being continuous can members of a series become parts
of a whole that is in motion as a whole. With these terms, the moved movers
are neither separate and randomly related to one another, as the atomists
would have it, nor self-identical, as is Plato's soul, nor even necessarily one
in definition. 78 Rather, they are "some one": through touching or continuity,
a whole of parts that are in motion essentially such that if the whole moves
no part can remain at rest.
ln this sense, either touching or continuity solves the objection to the
argument and is consistent with the primary thesis, that in a whole of parts
"everything moved is moved by something." The members of the infinite se
ries of moved movers are "some one," that is, they are one as a whole of parts
in motion. 79 But they are not one in any sense that challenges the individ
uals within the whole as moving from point X to point Y; the whole remains
a whole of parts. 80 And as we have seen, this concept of a whole of parts
underlies the entire argument of Physics 7 .1. Hence Aristotle's specifacation
of touching or continuity adds nothing new to the argument. lt also reveals
nothing new about the moved movers, their definition(s), or their essential
relations to one another. lt merely makes explicit the necessary conditions of
the original assumption of an infmite series of moved movers in motion
essentially.
Here in Ph,sics 7.1 Aristotle does not argue that the moved movers
must be touching or continuous, but merely says that "we see this to be uni
versally the case." However, in Ph,sics 7. 2 he specifies how the first mover
moves, namely as an àPX'l of motion; the remainder of Ph,sics 7 is then de
voted to arguments for the universal condition of touching or continuity. The
order of these arguments is telling: Aristotle intends first, in Ph,sics 7 .1, to
show that "everything moved is moved by something" and has excluded the
question of how or why the motion occurs. Hence he asserts only that we see
mover and moved always to be touching or continuous. The argument for
this assertion requires a further specification of the mover; hence it appears
only in the next part of the larger argument, in Ph,sics 7.2, after the mover
has been specified as an àPX'l of motion.
Ph,sics 7 .1 now concludes: the series of movers must be finite, so that
81
there must be a first mover and a first moved. That there must be a first
mover and a first moved is true for any series of moved movers even though
this conclusion has been reached only indirectly through a reductio
argument. 82
Parts, Wholes, and Morion
a
We can now summarize the proof of first mover in Plrysics 7 .1. The
first premise-"Everything that is in motion must be moved by something"
requires a whole of parts. The whole is in motion as a whole, and it either is
moved by an externat mover or is self-moved. If it is moved by an externat
mover, then it is obvious that it is moved by another; if it is a self-mover,
then the motion of the whole depends upon the motion of the parts. ln this
way, Aristotle reduces the self-mover to a special case of one thing being
moved by another.
The second premise-"the series of moved movers cannot go on to in
finity"-is established by a reductio ad absurdum argument that also presup·
poses a whole of parts, that is, a series consisting of an infinite number of
moved movers. The reductio argument reaches the contradiction that if we
assume an infinite series of moved movers, then an infinite motion would
take place in a finite time. Hence, it would appear that the series must be
finite, and there must be a first mover and a first moved.
But before drawing this conclusion, Aristotle raises an objection to the
proof, namely that no contradiction results if an infinite number of individ
ually completed motions occurs in a finite time. He specifies the moved mov
ers as "some one" through touching or continuity. Touching or continuity
renders the moved movers, and hence their motion, one in the sense that
their extremities must be either one in place or one and the same. Conse
quently, if any moved mover is in motion, both what precedes it as well as
what succeeds it must also be in motion. ln short, if the whole is in motion,
no part can be at rest. Therefore, touching or continuity must obtain be
tween the moved movers if the series is to be in motion essentially as a
whole. ln this sense, the supposed infinite series of moved movers must be
one and would undergo a single infinite motion in a finite time, which is
impœsible. Therefore, there must be a first mover and a first moved.
The entire argument from the opening premise to the concluding res
olution of the objection rests on this conception: a whole of parts moved
essentially, that is, as a whole. Consequently no conclusion follows concern•
ing the formai being or definition of the series or any subordination among
the parts. The argument is strictly conceived and founds only one conclu
sion: everything moved is moved bv another. Granting such a series, it can
not go on to infinity ; therefore, there must be a first mover and a first moved.
Herc Plrysics 7.1 concludes. The problems raised bv the claim that mover and
moved must be "together" occupy Plrysics 7. 2-5.
CONCLUSION
Even if the proof of Plrysics 7.1 is valid, its conclusion-that there must
be a first mover and a first moved-seems very limited. Aristotle does not
53
Arisrotle's Physics and lts Mediewl Varieries
even call this mover "unmoved."83 But in Plrysics 7.2, as he turns to the
daim that mover and moved must be together, he calls the first mover an
"o8Ev Tt ÙPX'I 'tflc; tc1.vriœroc;," a source whence of motion:
The first mover-not as "that for the sake of which" but whence
the source of the motion-is together with the moved. 84
The thesis that the first mover and moved are together, that nothing inter•
venes between them, occupies the remainder of Plrysics 7.2. 85 Plrysics 7.3
through 7.5 then take up more specialized problems entailed by the propo·
sition "everything moved is moved by something."
At the outset of Plrysics 7.2, Aristotle parenthetically indicates that the
first mover acts as a "source of motion" and not as a "that for the sake of
which." What does this designation add to the argument of Plrysics 7.1 and
to our knowledge of the first mover reached by this argument? "That for the
sake of which" usually means "end" or "final cause," while "source," or
86
"àPX'l," means "moving cause" or "agent." While a final cause moves by
being unmoved (i.e., it produces motion as an object of love), a moving
cause moves by being moved. 87 ln this sense, moving causes and final causes
are mutually exclusive.
Here we reach the most difficult and famous problem associated with
the argument of Plrysics 7. In Plrysics 8, when Aristotle argues that everything
moved is moved by another, such that there must be a first mover, he con•
cludes initially that the first mover must be unmoved and finally that it is
partless, immaterial, and without magnitude. 88 However, the first mover is
not specified as a moving cause or as a final cause; the issue is left open. ln
Meraplrysics 12, the argument that everything moved is moved by another
leads to a first mover who is unmoved and acts as a final cause-indeed this
mover is god, who moves the heavens as the highest object of love.89 Thus,
it would seem that Aristotle is in serious trouble between Plrysics 7 and Meta·
90
plrysics 12. If final causality excludes moving causality, then Plrysics 7, Plrys
ics 8, and Meraplrysics 12 assert either different first movers or different modes
of causality within the same first mover. Either these two first movers (or two
modes of causality) must be bridged, or Aristotle's arguments seem
91
incoherent.
1 shall offer a solution to this problem and suggest that Aristotle is not
in as much trouble as is usually thought. Even though three separate texts,
Plrysics 7, Plrysics 8, and Meraplrysics 12 argue that everything moved is moved
by another and conclude that there must be a first mover, they nevertheless
operate on different conceptions and have independent domains. In this
sense, even though they appear to prove the same proposition, nevertheless
Plrysics 7, Plrysics 8, and ·Meratm,sics 12 are different and independent
arguments. 92
54
Parts, Wlwles, and Motion
Plr,sics 7.1 reaches a conclusion ail its own, and this conclusion should
not be confused with that of Plr,sics 8 or Meraphysics 12. Indeed, Aristotle's
specification of the first mover of Plr,sics 7 must be understood within the
formai terms of this argument. These terms are established by the proof of
Plr,sics 7.1 and then constitute the conceptual domain fur the remainder of
Plr,sics 7. Thus, the specification of the first mover as an ÙPX'I 'tT)c; ICI.V·
11œmc; in Plr,sics 7. 2 and the subsequent arguments about mover/moved re•
lations are subordinated to this proof and present solutions to the special
problems presented by its terms, especially the notion of being "together."
Finally, because this argument differs from that of Plr,sics 8 (1 shall ar•
gue this case in the next chapter) and that of Meraplrysics 12, it is not im
mediately clear that the first movers of these three arguments can be
identified or even immediately compared. 1 shall suggest that these argu
ments do not reduce to some common thesis; consequently, ail three are re•
quired within Aristotle's larger theory of nature. Let us look at these issues in
the arguments themselves.
What exactly does Plr,sics 7.1 prove? The argument opens with the pri
mary thesis of the book: everything moved is moved by another. The impor
tant case fur this argument is the self-mover and the reduction of self-motion
to motion by another. Aristotle conceives of the self-mover as a whole di·
visible into parts, and this conception underlies the remainder of the argu•
ment as well. Hence, we must consider exactly what is at stake in it.
ln Plr,sics 7.1, the whole of parts does not entai( a direct view of the
parts, such that the argument accounts fur how or why motion occurs. Nor
does it entai( a direct use of Aristotle's definition of motion, actualization of
the potential by what is actual, or the concepts of potency and act. lndeed,
given that Plrysics 7 is an argument about movers and moved things, the com
plete absence of these notions is striking. Finally, it is not in any explicit way
about the cosmos or any particular part of the cosmos. The argument is fur
mulated universally: everything moved is moved by another; since everything
moved is moved by another, there is a series that cannot go to infinity, and
therefure, there must be a first mover.
Plr,sics 7.1 is about any whole of parts that is in motion as a whole. The
6rst argument is largely concerned with a self-moving whole of parts, and the
purpose of the argument is explicitly defined: it is to show that the self-mover
too is moved by another. Finally, the argument shows that the motion of the
whole depends upon that of the parts, but it neither says nor implies that
those parts are unmoved. If we move beyond the strict formai limit of Plr,sics
7.1 and consider the parts of a self-mover, such as the sailor walking, then we
can see that as a self-moving whole the sailor is in motion as a whole, be
cause soul moves body while being itself moved because it is located within
body. Although Aristotle elsewhere explains this relation-the soul is essen
tially unmoved but suffers an accidentai motion-such an account is neither
SS
Aristotle's Physics and lts Mrdieval Varieaes
possible nor nec�ry within the formai limits of Ph,sics 7.1. ln this argu
ment, Aristotle's sole purpose is to show that everything moved is moved by
another and that self-motion is no exception.
The second argument of Ph,sics 7. 1 takes this proposition as estab
lished in order to prove that the series implied by it cannot go on to infinity.
Aristotle uses a reductio ad absurdum argument, namely that the assumption
of an infinite series necessarily leads to the contradiction that an infinite mo
tion will take place in a finite time. The use of a reductio argument here is
significant: it suppresses any direct view of the mover/moved relation within
the series of moved movers. Hence, we do not reach a first mover because it
is required by motion or by the relation obtaining between mover and moved.
Rather, we reach a first mover only indirectly, that is, the opposite hypothesis
produces a contradiction. As a result, the argument reveals nothing of the
characteristics of the first mover or its relation to the first moved; the reduc
tio argument shows only rhat since "everything moved is moved by another,"
there must be a first mover and a first moved.
But before Aristode draws this conclusion, he raises an objection; there
can be an infinite number of individually completed motions; therefore, the
series of moved movers must form "some one" in order to exhibit some one
motion. They form a one through touching or continuity. ln regard to the
relation obtaining between the moved movers, this point would seem at last
to provide us with a direct specification of the relation obtaining between
them. But continuity or touching makes the moved movers one only insofar
as their extremities must either become one or be in the same place. Con
sequendy, the series of moved movers is one in the sense that no part can
remain at rest while the series as a whole moves. ln short, touching and con
tinuity unite the series as a whole of parts. But this argument, like its pre
decessors, indicates nothing about how or why the moved movers move;
consequendy, it adds no new specification to the initial assumption of a
whole of parts in motion as a whole.
Aristode now concludes that there must be a first mover and a first
moved. But what exacdy does this conclusion tell us? Since (contra Plato)
the self-mover, too, must be moved by another, and since there must be a first
mover, this first mover cannot be self-moved. Plato's self-moving soul cannot
be a first mover. (And indeed, for Aristotle, although soul is moved acci
dentally, it is not a self-mover. Only the sailor as a whole of soul and body is
a self-mover.) Furthermore (contra the atomists), the assumption of an in
finite series of moved movers entails a contradiction; therefore, there must be
a first mover and a first moved. (And indeed, for Aristode, soul, which is
essentially unmoved, is the first mover of the body.) And it tells us nothing
else-not even that the first mover is unmoved.
The conclusion of Ph,sics 7 is not incomplete; rather, it is the fullest
conclusion possible given the formai limits and domain of the argument.
56
Parts, Wholes, and Motion
Both substantively and historically the argument completely serves its pur
pose when self-motion is reduced to motion by another and an infinite series
of moved movers is shown to be contradictory. The proposition "everything
m9ved is moved by another" entails the necessity of a first mover.
ln Ph,sics 7.2 Aristotle specifies the first mover as an ÙPX'll, a source
or moving cause, rather than a tà 00 ÉVEICEV, a final cause. The most ob
vious implication here seems to be that this first mover is not unmoved. The
model here is the whole of parts whose motion depends upon the parts, so
that the whole is moved by the parts, while the parts may themselves be
moved within the whole.93 When one thing moves another and is "together"
with the moved, then it would seem that the mover must itself somehow be
moved. ln short, the specification of the first mover as a ÙPXTJ tT)c; ICLV·
'llOE<J>c; is exactly what we should expect, given the argument of Ph,sics 7.1,
which establishes that there must be a first mover; Ph,sics 7.2 answers a more
specialized question about that mover: is it a moving cause or a final cause?
Ph,sics 7.2 specifies how one thing moves another when they are "to•
gether" (i.e., by pushing, pulling, carrying, twirling, packing, and
combing).94 Again, the argument solves a problem raised by the condition
specified at the close of Ph,sics 7.1 and so further supports the main thesis
established there.
Here is the first conclusion about Ph,sics 7: because the argument that
"everything moved is moved by something" concerns a whole of parts in mo•
tion essentially, Ph,sics 7 reaches the necessity of a first originative cause of
motion, but it is not necessary that this first mover be unmoved. Expressed
formally, the motion of the whole depends on its parts, while the parts are
moved within the whole. The most serious case of such a whole, for Aris
totle, is a self-mover made up of body and soul. Soul is a first mover. That is,
soul originates motion in body, while being itself accidentally moved because
it is located within the body; consequently, the whole, as a whole composed
of parts (soul and body), is called self-moving.
Aristotle's "failure" to call this first mover of Ph,sics 7 "unmoved" is in
fact a success: the argument does not prove that the mover is unmoved. ln
fact, the whole of parts that operates throughout the argument suggests a first
mover that in a limited sense is moved, as when the parts of a whole are
moved with the whole even though the whole is moved by its parts.
ln Ph,sics 7.3, Aristotle discusses the soul/body relation at some
length, and although he does not mention it, the most obvious example is
the sailor walking on the deck of the ship.95 And again the problem being
addressed is properly referred back to Ph,sics 7.1. The sailor as a whole is a
self-mover. The soul moves the whole-and Aristotle calls the soul a "source
of motion "-while being moved due to its location in the sailor. Thus, soul
is a first mover and a source of motion but not an absolutely unmoved
mover.96
57
Arisrode's Physics and lts Mediewl Varieâes
58
Parts, Wholes, and Motion
59
Aristode's Physics and Its Mediewl Varieries
6o
Parts, Wlwles, and Motion
proposition. But if it is the same, why are there three separate arguments?
Why could Aristotle not prove bis point once and for ail in an argument that
would universally embrace ail these cases? Here we reach our final question
and face Aristotle's theory of nature as a whole.
First we may note that each argument applies universally within its do
main of objects. lt is universally true for any whole of parts in motion es
sentially that "everything moved is moved by something"; it is universally
true within a potency/act relation that "everything moved is moved by some
thing," be that motion natural or unnatural, animate or inanimate; a con
sideration of the causes and principles of substance yields the same
conclusion, namely "Everything moved is moved by something." But it is
also true that each of these arguments addresses a different problem, that is,
establishes a different thesis and reaches different conclusions. Plrysics 7 con
cerns motion in a whole of parts, Plrysics 8, the eternity of motion in things,
and Meraplrysics 12 the causes and principles of substance.
ln short, however often the same proposition appears within various
arguments, its presence does not mean that Aristotle is trying to prove that
proposition to be true as a proposition apart from the immediate problem and
domain of the argument at band. These three arguments look the same only
if one performs a radical act of abstraction and pulls this one proposition from
each of the arguments. But we can see how arbitrary such an abstraction
would be by noticing the very different status and role of this proposition
within the different arguments. So, for example, the proposition that "ev
erything moved is moved by something," opens Plrysics 7 and constitutes its
main thesis, while in Plrysics 8 the same proposition appears only in a reso
lution of an objection after the main thesis bas been established.
If we do not arbitrarily abstract a single proposition from three argu
ments, then we see that these arguments address different problems and bear
upon different objects (or the same objects in different respects). Here we
reach the heart of the matter. As Aristotle so often says: "being falls imme
diately into the categories," and there is neither some one category of being
nor some one element common to ail the categories.111 If there were, then
the requirements of ail being and motion could be reached by considering
this one category or one common element. But there is not. So Aristotle
must solve the various problems involved in being and motion as we find
them immediately cast in beings. ln short, the problem of motion in a whole
of parts, the problem of motion as eternal in things, and the problem of the
principles and causes of substance do not reduce to some one common prob
lem but remain independent and, so, in need of independent investiga
tions. And, as l have suggested, these domains are defined at the opening of
each logos.
Plrysics 7, Plrysics 8, and Meraplrysics 12 each defines and then takes up
a problem-a whole of parts exhibiting motion, that motion in things is
61
Aristode's Physics and lu Medieval Varieâes
etemal, and the causes and principles of substance; each solves its respective
problem by reaching the conclusions that are universal within the domain set
by that problem and the concepts required by it. Because these problems and
the domains defined by them cannot be reduced to some common element,
or common viewpoint, Aristotle requires separate arguments for three sepa
rate ways in which being is found: as substance, as potency/act, and as a
whole of parts. And in this sense, his account of motion requires each of
these unique and independent arguments, Mefal)lrysics 12, Plrysics 8, and
Plrysics 7.
Chat,r.er 3
65
Arisrode's Physics and lts Medievœ Varieties
After his initial proof of motion's eternity (Plrysics 8.1), Aristotle raises
and resolves three objections to the view that motion must be eternal (Plrys
ics 8.2); he rerormulates these objections into two questions about the struc
ture of things in motion and answers each question with a separate argument
(Plrysics 8.3-6 and 8. 7-10). The first argument establishes the structure of
the cosmos, such that some things are unmoved, some things always move,
and some alternate between motion and rest. 18 Without something actually
moving forever, motion in things cannot be eternal; this argument identifies
the eternally moving thing and the cause required by it.
The second argument (Plrysics 8. 7-10) answers the question: what mo
tion is capable of being "necessarily one and the same and continuous and
primary?" 19 Again, without such a first motion, motion in things cannot be
eternal. Aristotle identifies this motion as circular locomotion, which re
quires a first mover "indivisible, both partless and having no magnitude."20
lndeed, the identification of the mover required by circular locomotion
closes Plrysics 8 for two reasons. First, it completely resolves the problem at
stake, namely, what motion can be first and eternal, and what are its char
acteristics and requirements. Secondly, nothing more can be said about such
a mover within the domain of physics.
We turn now to the first argument, which considers "the reason why
some things that are at one time are moved and at another rest again?" 2 1
Aristode immediately indicates his own position: "some things that are are
always unmoved, but others always are moved, and others partake of both." 22
The overall argument is easy: everything that is moved is moved by
another; 23 the series cannot go on to infinity; 24 thererore, there must be a
first mover. 2 5 The first mover must be either self-moved or unmoved. Ulti
mately, Aristotle concludes, it must be unmoved and unvarying, so as to pro
duce a motion eternal, one, and simple. 26 This first effect bears a varying
relation to other things that in their turns are moved by it; because the mo
tion in other things is produced by something itself moving, these things ex
hibit the greatest variety in their motion, that is, they start and stop. 27 Thus,
the structure of the cosmos answers the initial question: the first mover is
motionless, while the first moved is always in motion; consequently, ail else
sometimes moves and sometimes rests. 28 This structure reconfirms the thesis
of Plrysics 8.1: motion in things must be eternal.
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Such a view of the structure of the arguments and the limitations that
it imposes on their conclusions offers two advantages. (1) lt provides a pa
thology for the difficulties of other readings of Plrysics 8. Any reading that
examines individual arguments without attention to the subordination of
these arguments to the main thesis of the book implicitly treats them as se
quential rather than subordinated. That is, the content of the individual ar
guments is thought to be unaffected by, or "neutral to," its position within
the structure of Plrysics 8 as a whole. 32 But a conception of arguments as se
quential is appropriate only to a nonteleological physics, such as mechanistic
physics. 33 lndeed, assumptions and criteria foreign to Aristotle's teleology are
first imposed here, in understanding the structure of Plrysics 8, befure the
reader has even turned to the specific content of the arguments.
(2) This view may daim to offer a "perfect fit" between the content
and structure of Aristotle's argument. This unity offers prima facie confirma
tion for the view itself and, 1 shall argue, yields a reading of Plrysics 8.4 in
which the argument is consistent and valid and fulfills its purpose within the
whole of Plrysics 8. We may now turn to Aristotle's arguments concerning the
motion of the elements.
Aristotle opens Physics 8.4 by dividing movers and things moved into
two mutually exclusive and exhaustive categories: some are moved acci
dentally, others essentially. 34 The motion is accidentai to what merely be
longs to or contains as a part that which moves or is moved, while it is
essential when the mover or moved is not merely a part of a thing. 35 Ap
parently dropping accidentai motion, the next words take up those things
that are moved essentially and begins the argument that everything moved is
moved by another. 36
This opening division establishes the subject matter of the argument
that follows: it concerns only essential motion. That is, it does not concern
things moved because they happen to be contained in something else; it con
cerns only things moved by virtue of a direct relation of mover to moved.
This relation is contact that results in the fulfillment of the movable qua
movable by a mover, a bearer of form, serving as "a source and cause of
motion."37 Here is the crucial point for the arguments of Plrysics 8.4: if the
argument that "everything moved is moved by another" is to be successful,
Aristotle must identify an essential cause, a direct cause of motion, for every
class of moved things. ln this sense, the division that opens Plrysics 8.4 pro
vides the criterion for its successful completion. With this criterion in mind
we can turn to the argument itself.
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Aristotle's Physics and lts Medieval Varieties
now examine this argument: the the elements are not self-moved, as are an•
imate beings, but must be moved by something actual relative to their po·
tency for motion.
Natural inanimate motion cannot be self-moved.48 Self-motion char•
acterizes animais as distinct from inanimate things and therefore cannot also
belong to inanimate things, such as earth or fire.49 First, if something moves
itself, presumably it may also rest itself.50 For example, an animal can walk
or not walk. However, the elements cannot naturally rest outside their proper
places.51 Outside its natural place, fire cannot but be moved upward, unless
it is held back by an externat constraint.
Again, if a thing moves itself upward, it should also be able to move it·
self downward.52 Genuinely self -moved things appear to determine the direc
tion of their motion. The elements, which are "heavy and light," do not seem
to have such an ability ; rather, their motion is one-directional-whenever
possible, fire is moved upward and earth downward. Consequently, they do
not seem to be self-moved.53
"Again, how is something continuous and naturally connected able to
move itself by itself?"54 lnsofar as a thing is actually one and continuous, it
is indivisible; therefore, it cannot at the same time, in the same respect, suf
fer opposite attributes.55 Hence, anything one and continuous is undivided
and can never be both agent and patient (i.e., both mover and moved).56
Indeed, animais are self-moved precisely because they are divided into soul,
the mover, and body, the moved. Hence, whatever is not so divided, but is
one and continuous, as are the elements, cannot be self•moved.57
These arguments systematically deny the characteristics of animate mo•
tion, requiring a body/soul distinction, to elemental motion. ln this context,
the characteristics of elemental motion emerge and may be summarized. El
emental motion must occur if the element is outside its natural place and this
motion is one-directional, that is, toward its natural place. Given the op·
portunity, fire cannot fail to go upward and earth downward. Furthermore,
the elements are moved as naturally one and continuous. The mover of the
elements cannot violate, and should account for, these characteristics of el
emental motion. (And the argument is specifically restticted to essential
movers and motions.)
The stage is now set for the second, more complicated, part of the ar·
gument. To uncover the mover required by the structure of the cosmos (and
his own larger argument), Aristotle analyzes the meaning of nanmzl as ap·
plied to movers and moved things. Natural motion, as it emerges in this anal
ysis, always requires a mover. Since elemental motion is "natural" and all
natural motion requires a mover, this analysis should uncover the essential
mover of the elements when they are moved naturally.
The argument requires three steps. ( 1) Aristotle characterizes movers
(i.e., actuality) and moved things (i.e., potentiality) as unnatural or natural
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and then asserts that the elements follow the model of natural motion. (2)
However, Aristotle admits, the essential mover during elemental motion re
mains obscure, because within natural motion the word potential is ambigu
ous. He distinguishes two meanings of potential, gives a complicated example,
and (3) concludes the argument by applying this distinction to the motion of
the elements. Let us turn to these three steps.
(1) The initial distinction between motions as natural and unnatural
also applies to movers.58 For example, a lever moves its object unnaturally,
because "the lever is not by nature capable of moving what is heavy."59 By
contrast, a mover acts naturally, when, "for example, what is actually hot is
by nature capable of moving something potentially hot."60 The potentially
hot in this case is also said to be "naturally movable when it contains the
suchlike principle in itself."61 These distinctions are compressed and require
some explanation.
A lever, such as a stick or rod, may be used as an instrument for lift
ing something heavy; but in itself the lever, too, is heavy and, as heavy,
goes downward whenever possible, as when dropped. ln other words, a lever
by its intrinsic nature goes downward and lifts a weight upward only when
external force is applied to it, as when someone presses on it. Externat force
characterizes violent or unnatural motion, and in this sense the lever pro
duces motion "unnaturally." Since the problem of elemental motion con
cerns natural motion, the example of the lever contrasts with, and so
emphasizes the point that the mover of the elements moves its abject not by
force, but by nature.
Herc is the more important case. "What is actually hot" (e.g., a burn
ing stick) is hot by virtue of actualizing an essential attribute. Hence, if
something else (e.g., paper) possesses the ability to burn as an essential at
tribute, natural motion immediately follows upon contact between the two;
the burning stick will set the paper on fire. No externat force is required,
because the mover acts, and the moved is acted upon, strictly in virtue of
what they are by nature.62
The notion of "natural" here implies three conditions. (a) "Natural"
excludes reference to any force outside the immediate relation between mover
and moved, act and potency. (b) The two individuals (e.g., a burning stick
and paper) must be in contact; when this condition is met, actuality is al
ways, by its definition, effi.cacious. 63 (c) Natural motion requires that the ca
pacity of the moved and the actuality of the mover be the same; for example,
ability to burn and actually burning both share the same principle, burning.
Aristotle's expression "the suchlike principle" ('t'IV àPX'IV 't'IV
'tOLU'U'n)'V) emphasizes this third requirement. When natural motion occurs,
the essential mover and the moved share one and the same actuality.64 The
burning stick is actually hot, and the paper is potentially hot. Upon contact,
both are immediately actually hot and as such indistinguishable-they both
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Aristode's Physics and lts Medieval Varielies
burn. Furthermore, they both burn by nature, that is, simply in virtue of
what they are without reference to any externat force. 65
Aristotle now applies the distinction between natural and unnatural to
the elements. "But fire and earth are moved by something by force on the
one band when [the motion) is contrary to nature, and on the other hand,
by nature when being potential [they are moved) toward their actualities."66
The motion is violent when unnatural, that is, moved by extrinsic force away
from the element's natural place, as when a stone is thrown upward. But the
motion of an element is natural when it develops its intrinsic capacity for
"proper activity."
The pl'oper activity of each element is to go to its proper place. Thus,
since "upward" is the proper place of fire, its proper activity, which it possesses
potentially and will exercise whenever possible, is to be moved upward; like
wise the proper activity of earth is to be moved downward. The potential to
be moved toward its respective natural place belongs to each element intrin
sically; in the presence of the proper actuality this potential cannot do other•
wise than be actualized: the element must be moved toward its natural place.
No further cause, no external force, is required. Earth, which possesses the po·
tential to go downward, may be compared to wood, which possesses the poten·
tial to burn; on contact with fire, wood immediately actualizes its potential,
and on contact with its mover, earth will immediately be moved downward.
Thus far, the account of elemental motion as the actualization of
a proper activity satisfies two of the conditions set out earlier. lt explains
why the motion of the elements is one-directional only: the proper activity
of each if immediately and exclusively oriented toward its natural place. lt
also explains why each element must be moved whenever it is out of its
natural place: on contact with actuality, proper activity always and immedi
ately results.
But the account remains incomplete. To show that "everything moved
is moved by something," Aristotle must show that the capacity of each ele•
ment, fire to be moved upward and earth downward, is actualized by some·
thing. Aristotle argues that a mover moves naturally when what is actually
hot moves what is potentially hot. But what is the essential mover, the ac•
tuality, when the elements are moved naturally? A further distinction is re•
quired, and here Aristotle moves to the second step of the argument.
(2) The mover during elemental motion remains obscure because, Ar
istotle says, of the dual meaning of "potentially." He illustrates this dual
meaning with a complicated example and daims that "and this is similar also
in regard to natural bodies". 67 The example, referred to again later in the
argument, is not, prima facie, very clear:
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Wlr;y Fire Goes Up
But before we return to the problem of elemental motion, the most im
portant question concerning the example remains: what moves a potential
knower to exercise of knowledge? Actuality. Actuality always produces actu·
alization of the potential qua potential. Actuality must produce motion both
from pure potency to habit and from habit to actuality. The actuality of
someone with the habit of science is the active exercise of the knowledge.72
ln the case of the doctor, motion from the habit of medicine to exercise of
knowledge occurs because the doctor possesses actual knowledge. Another
activity, such as eating or praying, may hinder the active exercise of knowl
edge. But the call "ls there a doctor in the bouse?" terminates the hindering
activity by turning the doctor's attention to a medical problem, and exercise
ofknowledge immediately follows (if the doctor is not drunk, etc.). After ail,
if there were not an actual, rather than a "purely potential," doctor available,
then there would be no doctor to respond to the call.
This explanation-that the motion from habit to actuality is produced
by the actual knowledge-presupposes that acquisition of knowledge has oc
curred. But what moves pure potential to habit? Actuality. Obviously, the
beginning medical student is not moved by an already possessed knowledge of
science. The abjects or "facts" of the science in the fullest sense actualize
pure potency for knowledge. ln medicine, for example, "facts" such as anat·
omy, drugs, diseases, and so on, insofar as they relate to the health of a per
san, serve as the abjects of the science. These "facts" themselves actualize
an ability to learn into the habit of knowledge. 73 Thus these "facts" serve
as the formai abjects of science and so actualize our potency for knowledge:
the actuality of the facts is the actuality of the mind during learning and then
after learning has occurred. 74 Once the mind bas achieved formai identity
with these "facts," the mind has the actuality of the facts of science and pos·
sesses "habit," when it is not fully operative, and actual knowing, when it is
fully operative.75
ln both these cases, "pure potency " and "habit," the actuality is the
same: the abjects of the science.76 The two senses of potential differ only in
relation to this actuality. The mind in pure potency must be actualized and
so corne to possess habit by the actuality of the abjects of science themselves;
the mind, after actualization by these abjects, can actively exercise knowl
edge on its own initiative. 77 Because after actualization has occurred, mind
has acquired the actuality of the abjects of science as its own, mind can itself
serve as actuality for the potential represented by the habit of science.78
This point illustrates two conditions required for elemental motion. (a)
The mover is distinct from the moved, and so in this case the proposition
"everything moved is moved by something" applies. (b) The motion is one
and continuous. The mover is distinct from the moved because the abjects of
the science are distinct from the mind, while the actualization is a contin
uous development from "pure potency " to habit to activity.79
75
Arisrode's Physics and Its Mediewl Varieâes
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Wiry Fire Goes Up
scientist, is the "certain situation, namely upward." Natural place is the ac•
4
tuality that moves the elements.8 Water-like the beginning student, who
cannot immediately practice science but must first acquire habit-cannot
immediately actualize its ability to rise; rather water can only rise mediately,
by first acquiring the habit of rising and being upward, that is, by first be
coming air. Air-like the habituai scientist who possesses the actuality of sci•
entific facts and 50 can immediately begin to exercise that knowledge
possesses the habit of rising and being upward; 50 in the absence of
hindrance, air immediately actualizes this activity, that is, it rises. (So, for
example, water in an open dish evaporates: it turns into air, which immedi
ately rises.)
The appropriate natural place is the actuality for the one-directional
natural motion of any element.85 Just as the orientation of the student is to•
ward the facts that constitute an active scientific knowledge, 50 the ele
ments, as either pure potency or habit, are actively oriented toward their
natural place. Thus elemental motion, in this view, meets the criteria estab
lished earlier. Everything moved is moved by 50mething; each element is
moved by its respective natural place.86
The criteria established early on in the argument are hereby met. The
motion of the elements is natural in the sense that the potency is intrinsic
and no extemal force is needed. This motion is one-directional only, namely,
only toward that natural place that serves as the actuality of the element.
The motion is one and continuous, that is, a development from pure potency
to habit to activity, and is produced by one actuality, respective natural
place. And, finally, the actuality (e.g., upward for air) of natural place, and
the potency (e.g., potentially tending to rise and be upward) are "suchlike"
principles shared by potency and actuality.
This understanding is confirmed by Aristotle's dual meaning of po·
tency, "pure potency," such as the person ignorant but able to learn, and
"habit," such as the knowledgeable person not at the moment exercising that
knowledge. Actuality, as in the exercise of knowledge, is the activity that
completes the entire development. Because habit is intermediate between
pure potency and full actuality, it is both partially developed and partially
incomplete, requiring further development; ln Aristotle's initial example,
the person with the "habit" of science remains a "potential" knower; but in
the case of the elements, air, with the "habit" of rising, is "actually light."
Both instances represent "habit," the intermediate moment in the process of
actualization. The habituai scientist is between ignorance and exercising
knowledge, white air is between being heavy and actively rising. And habit
changes its meaning from partially potential to partially actual, because Ar·
istotle shifts the argument from distinguishing two meanings of potential
to identifying the mover with actuality during elemental motion. And, to
repeat, that actuality (i.e., the essential mover) for the elements is the
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Aristode's Physics and hs Mediewl Varieâes
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Aristode's Physics and lrs Medieval Varieties
that, then, none of these things moves itself by itself is clear; but
it has a source of motion, not of moving something or of produc•
ing motion, but of suffering it. 95
ln a sense, this sentence contains the entire argument. Aristotle again denies
that the elements are moved internally by a soul. Nevertheless, the elements
do contain a source of motion in themselves. 96
Aristotle's word SOUTce ( T) àPX'I\) is quite general, and he uses it in a
variety of ways. For example he calls soul a "source of motion."97 To clarify
his meaning, Aristotle adds an explanatory note to the notion of "source of
motion." The source possessed by the element does not move it or make its
motion. Earlier, when denying that the elements are animate, Aristotle uses
just these words, "KLVEÎ.v" and "m>LEÎ.V," to describe animate motion.98
Hence, the repetition of these words in the conclusion emphasizes that the
"source of motion" in the element is not a soul. Rather, the elements possess
a source of "undergoing" (XŒO')(ELV) motion. 99 That is to say, an element as
potential-a potential that by definition is oriented toward its "suchlike" ac
tuality-is actualized by its proper actuality first into habit and then into full
actuality or activity.
Without hindrance, the motion of the elements is natural, necessary,
one, and continuous; furthermore, as potency oriented toward the actuality of
its respective natural place, it is one-directional. Ali the initial conditions for
an account of elemental motion are met. The potency/act relation between the
elements and respective natural place unites the potency of the element and
the actuality of its proper place. The mover/moved relation is neither com•
pletely intrinsic to the element, as is soul, during animate motion, nor corn•
pletely extrinsic to the element, as is the mover during violent motion. The
motion of the elements as both inanimate and natural cuts across these more
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Aristode's Physics and lts Medieval Varieries
between mover and moved. So these readers require these characteristics for
the mover of the elements. Both Albertus Magnus and Thomas Aquinas, for
example, identify the "generator" of the element as the cause of motion from
potency to habit. 119 But the motion from habit to actuality either remains
problematic or must be explained as caused by the generator, too, in the act
of producing habit. This last explanation is a long story that quicldy aban•
dons a direct relation to the text of Plrysics 8.4. Where is such a mover in
Aristotle's example, after a ball leaves the thrower's band or as the roof
falls? 120 In fact, the history of criticisms of Aristotle's argument on this re•
quirement is so important that it virtually forms a separate chapter in the
history of ideas.
Here we may retum to Plrysia 8.4. The identification of an actuality
that constitutes the requisite mover during elemental motion satisfies the
conditions of the argument and the conclusion to be established. Indeed, the
argument for a mover during elemental motion is so strictly successful that
within it ail mechanics cl motion disappear. Strictly spealcing, the mechanics
of the mover/moved relation-how does the mover produce motion in the
moved-are excluded by the formai structure of this potency/act argument.
The identity between actuality and potency (e.g., burning, between the pa·
per and the stick) and the actuality of natural place for the elements unîtes
absolutely the essential possibility of being moved and the essential actuality
of causing motion. In the confines of this argument, the subordination of
moved to mover is so radical that the identification of a mover constitutes
a complete explanation of the motion of the elements. Actuality by defi
nition always moves its potency (if nothing hinders). ln this sense, the
subordination in the structure of the overall argument of Plrysia 8 closely
reflects the subordination of Aristotle's conception of effect/cause relations:
to trace the subordination of potency to its actuality is, in terms of potency
and act, to explain completely the potency and its actualization: why fire
goes upward.12 1
Chaprer 4
Now this [the mover] must be either in the middle or at the cir
cumference [of the sphere] for these are the principles of the
sphere. But things whose motion are fastest are nearest the
mover, and such [i.e., fastest] is the motion of the circumference;
so the mover is there. 1
Within the context of Plr;ysics 8 alone it is difficult to see how a first mover
possessing neither parts nor magnitude can be so located; beyond the Plr;ysics,
if, as is traditionally claimed, this mover is none other than the immaterial
god of Metaplrysics 12, then the position of the first mover "there," on the
circumference of the heavens, becomes impossible.2 Consequendy, from Byz
antine times to the present, Aristode's commentators frequendy find in this
passage a mistalœ to be corrected.
Historically, the apparent location of the first mover on the circumfer
ence of the cosmos has been corrected in several way s: (1) Aristotle did not
mean to locate the first mover; rather, he intends to locate the effect of the
first mover. (2) Properly speaking, the circumference of the cosmos is not a
place, and so being "there" does not locate the first mover. (3) Plr;ysics 8
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Aristode's Physics and lts Medieval Variecies
reaches a subordinate first mover, a sphere-soul, and does not concern god,
the first mover of the cosmos in Metaplrysics 12. This sphere-soul can be lo
cated "accidentally" while remaining "essentially" partless and without mag
nitude. Consequently, the internai problems of Plrysics 8 can be resolved, and
the "location" of this mover presents no difficulty vis à vis the god of Mera
plrysics 12. But on doser scrutiny each correction exacts a price of its own.
The first correction daims that Aristotle's argument here concerns not
the first mover directly, but where the mover acts. Thus, "Perhaps Aristotle
means that the mover acts on the circumference of the sphere to cause
rotation."3 This reading frees the mover from the taint of location by trans
ferring the "location" to the effect of the mover. But in so doing, a new con
cept is introduced into the argument: a specific "act'' of the mover on the
circumference of the cosmos. Since in Metaplrysics 12. 7 god does not act on
the cosmos at ail, but is a thinking on thinking that moves as an object of
desire, this correction exacerbates the apparent tension between Plrysics 8
and Metaplrysics 12. And indeed, for Aristotle's commentators the question of
how the first mover of Physics 8 "acts" has had a long and varied life of its
own. 4 Since this correction is so important both in reading Aristotle's Plrysics
and in its history, it requires consideration.
As I have argued, Plrysics 8 becomes coherent only if we understand it
as bearing upon the causal requirements of etemal motion in things. The
argument concerns what motion is able to be eternal and then condudes
with an account of the causal requirements of such a motion. Hence the
argument remains within physics as Aristotle defines it: motion exhibited
in natural things, induding the causes required by this motion. ln the argu
ment of Plrysics 8, Aristotle condudes only that the first motion must be
continuous and, consequently, that the first mover must be unmoved, in
variable, and without parts or magnitude, because only such a first mover
could produce the first continuous motion. The characteristics of the first
mover are determined strictly by an analysis of the requirements of the
fir st eternal motion.
But our famous correction-reading the "location" of the first mover
in Plrysics 8 as indicating an act of the first mover relative to the circumfer
ence of the cosmos-violates this strict understanding of physics as a science.
lt reads into the argument an explicit statement about the first unmoved
mover, namely, that it acts on the circumference of the cosmos, and describes
the first mover independently of the strict requirements of motion in things.
Such a description abandons the requirements of motion to introduce the
question (and the controversy) of how the first mover produces motion. But
this question has been (and remains) problematic precisely because Aristotle
neither raises it nor address it in this argument. Consequently, this correc
tion resolves one problem at the expense of creating another foreign both to
physics as a science and to this argument of Plrysics 8. 7-10.
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Being On the Edge
Motion and things exhibiting motion serve as the starting point of ail
physics. The reality of motion as exhibited in natural things cannot itself be
proven-nor is such a proof required by physics-but must be assumed by the
physicist as his starting point.9 However, once the reality and importance of
motion in things is assumed, a number of questions arise, such as what is the
definition of motion, must there always be a cause of motion, is motion eter
nal. This last question opens the argument of Plr,sics 8. In Plr,sics 8.1, Ar
istotle asks if motion is etemal or if motion began only to end someday. 10
Motion, he concludes, must be etemal, but only because it is eternally pro
duced by a 6rst cause; he raises three possible objections to this view, and
resolutions of them occupy the remainder of the book. Two objections reduce
to a single question, and the resolution of it and the remaining objection
comprise two arguments (Plr,sics 8.3-6 and 8. 7-10) that motion in things
must be etemal because it is etemally produced by a 6rst unmoved mover.
ln the last chapter, we considered the first argument, Plrysics 8.3-6.
Here we tum directly to the second argument, which contains the disputed
"location" passage and takes up the third and last objection raised in Plrysics
8.2: if motion is etemal, there must be a continuous motion; what motion,
if any, can be continuous and primary? 11 A consideration of the different
types of motion (alteration, increase and decrease, and locomotion) shows
circular locomotion to be the only possible primary and continuous motion.
But to be actually continuous and primary, circular locomotion must be pro
duced by a first unmoved mover. Aristotle concludes that an etemal contin
uous circular locomotion necessarily requires a first mover indivisible,
without parts, and without magnitude. 12 This conclusion concerning the
first mover required by the 6rst continuous motion closes Plr,sics 8 (and the
Plrysics as a whole): it is the fullest description of a first mover to occur within
the domain of physics, that is, the domain of things containing within them
selves a principle of motion.
The order of these two arguments œlr,sics 8.3-6 and 8. 7-10) is not
without significance. The first resolves a problem conceming the etemity of
motion in things by exhibiting the overall structure of the cosmos. lt con
cludes with a classification of ail things according to their ability to undergo
motion. The first mover reached here is sharply de6ned in terms of motion:
Aristotle concludes that the first mover must be absolutely unmoved, unable
to undergo motion either accidentally or essentially.
The second argument concems the 6rst etemal and continuous mo
tion. That is, it resolves an objection directed at the "middle" category of
things that exhibit motion: what kind of motion do those things always in
motion exhibit? ln this sense, the second argument (which "starts anew")
presupposes and offers a further development of the conclusion reached in
88
the flrst argument. Aristotle again concludes that there must be a first mover
and methodically limits his description of the 6rst mover to the requirements
of the 6rst motion. The presence of an eternal continuous 6rst motion re
quires a flrst mover without parts, without magnitude, and invariable, both
in itself and in relation to the first moved.
With this structural view of Plr,sics 8, let us tum to the second argu
ment conceming motion and containing the disputed "location" passage.
Plr,sics 8. 7 opens with a question: can there be a continuous motion, and if
so, what motion will it be? Aristotle argues that only circular locomotion can
be single, continuous, and in6nite: circular locomotion is the primary
motion. 13 The remainder of the argument follows from the nature of the flrst
motion-that it talces place in an infinite time and in a magnitude-and,
Aristotle concludes, this motion requires a 6rst mover without parts and
without magnitude. 14
The 6rst part of the argument considers motion as occupying an infi
nite time and concludes that the 6rst mover must be without magnitude.
Motion in an in6nite time requires an infinite force; an infinite force cannot
reside either in a 6nite or in an inflnite magnitude. The conclusion seems to
follow that the first mover, responsible for motion in an infmite time, must
be without magnitude.
But before drawing this conclusion, Aristotle anticipates an objection.
Sorne things (e.g., a thrown discus) exhibit apparently continuous motion
after losing contact with their initial (and apparent) mover (e.g., the
thrower). Such things do not seem to require contact with a mover, or even
to require a mover at ail, once they are set into motion; presumably, the first
eternal motion could be such a motion. ln this case, Aristotle's conclusion
would not follow: motion in an infinite time would not require a first un
moved mover without magnitude.
Aristotle dismisses this objection in two steps. He first denies that the
apparent exception involves continuous motion-a thrown discus, for exam
ple, undergoes a series of contiguous motions and so is unlilce the first con
ânuous motion; he then denies that the apparent exception is an exception
after ail: even here the law "everything that is moved must be moved by
something" applies-a thrown discus is indeed moved by a succession of
moved movers that are in contact with it. Hence the objection does not ap
ply to the 6rst continuous motion and its requirement of a first mover. 15
Aristotle retums to the main line of the argument, summing up and
explicating the position he has developed throughout the whole of Plr,sics 8
beû>re reaching his final conclusions. This summation introduces two im
portant points into the argument: ( 1) that the first motion must involve
magnitude, and (2) the problem of location, usually talcen to be the loca
tion of the first mover. Here we reach the problematic "location" passage of
Plr,sics 8.
Aristode's Physics and lrs Mediew.d Varieries
90
Being On the Edge
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Aristot/e's Physics and lts Medieval Varieaes
Substantively, the first motion and the first moved (i.e., the magnitude
occupied by the first motion) are very closely linked. However, since Aris
totle has just specified that the first motion must occupy a magnitude, it
probably makes more sense to understand the present question as asking
where is that magnitude, namely, the first moved. ln this sense, the proper
grammatical subject of the sentence (i.e., the moved) and the proper subject
of the argument are identical: Aristotle is asking where is the first moved, at
the center or the circumference of the cosmos?
Finally, in the next line, Aristotle introduces the noun mooer into the
argument: "But things nearest the mover move most quickly and the motion
of the circumference is such; therdore, the mover [moves] there." The sen
tence begins with things in motion and places them nearest the first mover.
Herc is the actual and specific transition from motion and the moved to the
first mover; and this transition is made explicit by the introduction of the
noun mooer into the argument. Since Aristode does introduce the mover
here, we should follow his language and read it within the argument where he
himself does and not before.
The last phrase of the passage ( ÈICEÎ. apa 'tÔ ICLVOÛV) requires further
consideration. Prima facie, the most obvious verb to read here would, with
out doubt, be is: "therdore, the mover is there." Normally in construing an
elliptical clause such as this, the cognate verb is possible but not preferred.
But Plrysics 8 involves a special consideration. From the opening of this ar
gument at Plrysics 8. 7 the verb moves (ICLVEÎ.) regularly occurs with the noun
mooer ('tÔ ICLVOÛV). From the opening of the argument at Plrysics 8. 7 there are
six occurrences of the phrase 'tÔ ICLVOÛV ICLVEÎ.. 23 ln fact, the noun 'tÔ ICLVOÛV
occurs only once without the verb ICLVEÎ., namely, at the beginning of Plrysics
8.10, where the first mover is described as without parts and without
magnitude.24 Thus, in this argument, the cognate verb has a strong daim to
a place in the elliptical clause.
Finally, the phrase 'tO ICLVOÛV ICLVEÎ. projects the full sense of a first
mover required within physics, the science of things involving motion. Thus,
the mooer moves is the proper phrase to understand within the "location " pas
sage of Plrysics 8.10.
Construing the passage in this way offers a number of important ad
vantages. lt allows us to repeat the phrase the mooer moves regularly occurring
in the larger argument of Plrysics 8. 7-10. Furthermore, it allows us to follow
the same logic as that of the preceding argument, that is, to proceed from
motion and the first moved to the requisite first mover.
This reading also renders the meaning of the passage clear and concise.
The magnitude of the first motion introduces the problem of the relation be
tween mover and moved and the subsequent question of what moved can
both involve magnitude and most perfectly relate to a first mover without
magnitude. The answer is clear: the motion of the circumference moves most
Being On the Eclge
quickly and so must be "nearest," that is, most immediately related to, the
first mover. The objection is thus completely resolved, and the argument
can proceed.
But two questions remain. One is textual, the other historical. (1)
What are we to make of Aristotle's reference to an eternal continuous mo
tion that occurs at the middle of the sphere-a motion sufficiently perfect
to be considered as a candidate for the first motion of the cosmos? (2) If
this construction of the argument works so well, why has it not been sug•
gested before?
(1) What perfect continuous motion occurs at the middle of the
sphere? As we have seen in chapter 3, Aristotle argues in Plrysics 8.4 that
even the simple transformation of the elements into one another must fall
under the universal rule "Everything that is moved is moved by some
thing."25 He considers this transformational motion explicitly because it
seems to be the most difficult and remote case for his rule. Elsewhere, he re•
fers to this transformation of the elements into one another as an eternal cy
clical motion at the center of the earth, itself the center of the cosmos,
which corresponds to and in some sense completes the simple perfect motion
at the outermost boundary of the cosmos. 26 Elemental motion does indeed
have its own daim to being perfect motion. 27 Hence, Aristotle may have this
elemental motion in mind here.
(2) Why has this construal of the argument of Physics 8.10 never before
been suggested? Perhaps it has. Are we not returning to the first view rejected
at the beginning of this chapter-the view that this passage concerns the first
motion produced by the first mover? lndeed, we are back to the first motion
and the first moved in ail its likeness to the first mover. But with an impor·
tant, indeed crucial, difference. The first view makes the first mover, not the
first motion, the subject of the passage and the argument; hence it introduces
the problem of how the first mover produces its effect. 1 make the first moved
and the first motion the subject of the passage and the argument; the first
mover appears only as a requirement of this motion. Hence questions about
the first mover considered independently of motion are excluded.
This change is far from trivial. On it rests not only the proper subject
of this argument but also the rigorousness of physics as a science for Aristotle.
The "correction" rejected at the beginning of this paper takes the subject of
this disputed passage as the mover, and so the passage concerns "where the
first mover acts." Consequently, the main concern of Plrysics 8, the require
ments of motion, disappears to be replaced by the rather different problem of
the first mover and its productivity. But because physics is the science of
things that contain an intrinsic principle of motion, it should not contain
statements about 'tO àdvTJ'tOV ICLVOÛV independently of the requirements of
motion. Hence, on this reading, physics as a science breaks down (only a few
short lines befure the end of a long book), and here in Physics 8 a problem
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Aristode's Physics and lts Medieœl Varieâes
arises that neither in fact receives, nor in principle could receive, any further
treatment within the science of physics.
My construction makes motion in things, which is the proper subject
of physics as a science, the proper subject of this passage, too. Furthermore,
there is no reference to, no problem concerning, the productivity of the first
mover taken apart from the problem of motion. Physics as the science of nat
ural things remains completely intact, and Plr,sics 8 concludes with a full ex
plication of the requirements of motion as eternal.
Here, speaking historically, we have a pathology of the problem: be
cause Plr,sics 8 is traditionally read as a proof of a first mover, Aristotle's read
ers can hardly wait to reach the proper object of the argument, and so,
having the first mover in mind throughout, they read this mover into the text
at the first pouible moment. In so doing, they shift the proper subject of the
argument, distort its purpose, and generate problems such as that of the in
famous "location" passage.
While it is undeniably true that Plr,sics 8 supplies two arguments re
quiring a first unmoved mover, it is false that the first mover is the immediate
and proper subject of these arguments. Aristotle intends to prove the eternity
of motion, "a sort of life, as it were, to ail naturally constituted things"-and
in so doing, he reveals and explains the requirements of motion as eternal. 28
Hence, the arguments of Plrysics 8 properly fall within the domain of physics,
according to Aristotle's own definition; they resolve a problem concerning
the location of the first moved (and hence also the first motion) by indicat
ing that it must be on the outermost circumference of the cosmos.
94
Part Il
Aristotle opens Plrysics 2.1 by dividing things that are into those that
are by nature and those that are through other causes, such as art. 1 Since
nature, and things that are by nature, constitute the proper subject of phys
ics, their definition is central to natural philosophy. But Aristotle character
izes nature, and hence things that are by nature, in two apparently different
ways. (1) Nature is a source of motion and stationariness (ÙPXfl KLVTIOE�
Kat O'tClOE�). 2 Herc, nature may be understood as a mover. (2) Nature is
"some source and cause of being moved and of being at rest in that to which
it belongs primarily, in virtue of itself and not accidentally" ( ooç OÜOT)ç 'tflÇ
cj>uœa>ç àPXÎlç 'tLVÔç Kat at'tl'.aç 'tOÛ KLVEL<J8ŒL Kat 'IPEJ'ELV Èv lt>
\JXŒPXEL xp6rt0>ç Ka8' aÛ'tÔ Kat µfi Ka'tà auµPEfh'1K6�.)3 That is, nature
is not a mover but a principle of being moved.
There are two ways to reconcile these formulations. Waterlow, for ex
ample, suggests that we should understand the passive form as active in
meaning. 4 Thus, nature is a principle of motion in the sense of being some
sort of mover. 5 Furthermore, she finds Aristotle's theory of nature to be in
deep trouble on exactly these grounds; his theory of motion, and his teleol
ogy more generally, she daims, do not stand up to close analysis. 6
Altematively, because in Greek the verb form is generally prior to and
more specific than the noun, "Nature is a principle of motion and rest" is
ambiguous as to whether nature is a mover or an ability to be moved. Thus,
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Aristode's Physics and Irs Mediewf Varieàes
For each of these things [i.e., animais, plants, their parts and the
elements) has in itself a principle of motion and rest, some ac
cording to place, some according to increase and decrease, and
some according to alteration. But a bed and a cloak and if there
is some other such kind insofar as they happen to be of each cat
egory, and insofar as each is by art, have no innate impulse for
change but insofar as they chance to be stone or earth or a mix
ture of these, they do have [an innate impulse for change) and
insofar as each is such, so that nature is some source and cause of
being moved and being at rest in that to which it belongs pri-
Aristotle and Philoponus
Herc we have the crucial passage. Aristotle concludes his account of "by na
ture" with the example, which he does not explain, of fire being carried up•
ward. For many commentators, including Philoponus, Thomas, and modern
readers, too, the problem of elemental motion, which is mentioned but not
argued here in Plrysics 2.1, becomes a sort of test case for what things are
14
by nature.
Within the Plrysics, the crucial text for the motion of the elements
the text that must one way or another fit together with the account of "by
nature" here in Plrysics 2.1-is Plrysics 8.4. 15 As we have seen, in Plrysics 8.4
Aristotle argues that everything moved must be moved by another and sep·
arates plants and animais, which are moved by soul, from the four elements,
earth, air, fire, and water. lt is impossible, he says, for the elements to be
besouled and so self-moving. 16 Consequently, as we have seen, identifying
their mover during natural motion presents Aristotle with a difficult problem:
there is no visible external mover, and there is no soul to act as an intrinsic
mover, so what produces natural elemental motion? As we have seen, the
actuality of being up moves air upward. 17
As things that are by nature, the elements present a second problem.
They (and their natural motions) are "by nature"; but they are not besouled
and so cannot be self-moved. Consequently, being besouled and self-moved
cannot be the essential characteristic of things that are by nature. What then
is the essential characteristic of such things? Herc we can recall and develop
further some of the points made earlier.
After defining nature, Aristotle compares and contrasts things that are
by nature with those that are by art. Both are identified primarily and actu•
ally with form, but they differ because a work of art does not have "the source
in itself of its making" ('t'fV ctPXT)V Èv Éau,ip tric; JtOL'l<JEO>c;)-it requires an
external agent to impose form upon matter, because, we might say, they do
not go together "naturally" or "by nature."18
But in "things that are by nature," form and matter go together imme
diately, without reference to any external agent. This relation lies at the
heart of Aristotle's notion of "things that are by nature" and explains why
form as actuality and matter as potency go together immediately, that is,
without reference to any third cause. lt requires two related concepts: (1)
formas actuality and (2) matter as potential oriented toward actuality.
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Arisrode's Physics and lts Mediffl.d Varieâes
( 1) The form of a natural thing, which serves as the object of the def•
inition, also constitutes the thing as actual. 19 But what is actual causes mo·
tion in the potential. In this sense, form serves as a principle of motion. 20
(2) Form as actuality produces motion in natural things only because matter
as the potential of things that are by nature is not a passive principle for Ar·
istotle: matter "desires" form. 21 ln short, matter is mooed because it is actively
oriented toward form, which is at once a thing's being and, as actual, its prin•
ciple of motion. 22 So, for example, when man begets man, the father is the
moving cause because he brings form to matter; but once form and matter are
in contact, a new individual is immediately produced without reference to
any third cause. 23 Form need not be imposed upon matter in natural things,
because the matter is actively oriented toward its form, and form as actuality
is immediately efficacious as a cause: they go together "naturally" or "by na•
ture" without reference to any third cause, such as an artist.
Here we reach the crux of Aristotle's definition of nature as a "source
or cause of being moved." In things that are by nature, to be moved means to
be caused by another; but it does not mean to be passive. The passive (or
middle) infinitive indicates a causal relation in which matter is caused, that
is, as potential matter is moved immediately by form as actual; but matter is
moved not because it is passive but because it is actively oriented toward
proper form as actuality. 24 ln natural things, matter as potential is moved
because it "desires" form; consequently, in the absence of hindrance, the
matter as potential in natural things cannot fail to be moved, because, on the
one hand, form constitutes the actuality that by definition must be effica•
cious, and, on the other hand, a thing as potential is nothing other than an
active orientation toward, a desiring of, this actuality. No outside cause is
needed and, if nothing hinders, motion cannot fail to occur.
Again, nature contrasts with art, and the difference between them will
be telling for Philoponus. The matter of an artistic object has no innate im•
pulse toward its artistic form-a piece of marble has no orientation whatever
toward becoming a statue. lt is proper matter for a statue and in this way may
be said to be a potential statue; but here the potency is passive rather than
active and hence requires an artist to act on it from the outside. As a moving
cause, the artist contrasts sharply with the father; the father is a moving
cause of things that are by nature and serves to bring form into contact with
matter, because on contact form and matter "naturally" go together; the art•
ist, or maker, must impose form on matter, and if for some reason the work
is interrupted, it remains incomplete. 25
Nature and "things that are by nature" constitute the proper subject of
physics, and the unique characteristic of such things, that is, the intrinsic
relation between matter (or potential) and form (or actuality), underlies
much of Aristotle's philosophy of nature. Most broadly, it underlies his view
that disorder is never to be found among things that are by nature: nature is
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Aristode and Philopanus
always a cause of order. 26 This order cannot originate in form alone. If form
alone accounted for such order, art would be orderly in the same sense as is
nature, because both nature and art are primarily identified with form. But
art is not orderly in this way: a piece of wood need not become a bed and
indeed will not become anything artistic at ail without the causal agency of
the artist. Thus, the order of things that are by art does not lie in the thing
itself but in the artist; although Aristotle does not draw out the implication,
we can see here the reason why works of art canbe immediately identified by
the artist (e.g., a Rembrandt) even on the first viewing.
In contrast to art, nature is a principle of motion and rest, that is, a
principle of order such that fire is always carried upward; as such a principle,
nature requires the interlocking relation between matter as potency desiring
form as actuality, while form as actuality causes motion, itself defined as the
actualization of the potential qua potential. 27 Nature is a principle of order
precisely because no third cause is required: the relation of matter as potential
to form as actual never fails in the absence of externat hindrance.28
Here then is what Aristotle means when he speaks of things that are by
nature as having a source of motion and rest, an innate impulse to change,
or an ability to be moved or to be at rest. On the one hand, potency aims at
actuality, while, on the other hand, actuality on contact produces actualiza
tion of the potential qua potential. Thus, things that are by nature, although
like things that are by art in virtue ofbeing identified with form, are uniquely
characterized by the fact that when they move or change, they do so in virtue
of this intrinsic relation-matter desires form while it is moved by form
and without reference to any third cause. With this notion of things that are
by nature, we can return to the problem of the elements. Here is a test case,
as it were, of Aristotle's definition of nature. ln order to be "by nature" as
defined in Plrysics 2.1, the elements must possess an intrinsic ability, or in·
nate impulse, to be moved; Aristotle clearly affirms that they are by nature
and do possess such an ability.29 Given the argument of Plrysics 8.4, not only
must the elements possess an active orientation toward actuality, but Aris
totle must identify the actuality that serves as their mover. Only so will the
elements both be by nature andbe moved by another. Since nature is orderly,
the ability of the elements to be moved and the actuality that serves as their
mover must be such that their motion is always the same and no third cause
is needed.30 Thus, fire is always carried upward and earth downward.
The importance of the elements and their respective motions as "by
nature" can hardly be overemphasized. In the sublunar world, ail things are
composed of the four elements, earth, air, fire, and water. Thus, character•
izing things that are by art, Aristotle says that to the extent that they happen
tobe made of the elements, they too have an innate impulse to change. 31 So
the account of elemental motion as "by nature" is an account of the motion
of ail things insofar as they are natural.
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Aristotle's Physics and lts Medieval Varieties
As we have seen, the elements are not internally divided; rather, each
is a "continuous and naturally connected substance."32 Furthermore, each
possesses only one lcind of matter, which explains why it can move in one
direction only: "A thing then having such matter is light and always upward
and that [having) the opposite is heavy and always downward."33 As contin•
uous and simple in this sense, the elements can be defined: fire is defined as
light, which means "potentially up"; earth is heavy, "potentially clown"; air
34
and water, the middle elements, are potentially in the middle. This orien•
tation (e. g. , fire upward and earth downward) constitutes the very being of
the elements. 35
Here is the solution to the first part of the puzzle about the elements.
The elements are properly spolcen of as "things that are by nature," because
each possesses an innate impulse, or innate ability to be moved. So fire is
always moved upward, and earth downward, in virtue of their simple con•
tinuous matter. 36 As in Plrysics 2, nature is not immediately conceived as a
mover; rather, it is an ability to be moved expressed as an active orientation
of matter or potency toward its proper actuality. 37
This solution raises the second problem involved in elemental motion
as "by nature." If the elements, such as fire and earth, are continuous nat•
urally connected substances that cannot contain an intrinsic mover (Plrysics
8.4. 255a8-15) and, furthermore, are constituted by one lcind of matter,
such that fire is always carried upward and earth downward (De Caelo
4.5.312a23), then what-and "where"-is the actuality that serves as the
mover of the elements? Toward what actuality is each of the elements ori•
ented? The very definition of the elements is "potentially up" in the case of
fire, "potentially down" in the case of earth, and in natural things what is
potential desires the actuality from which it gains its definition; conse•
quently, the actuality of the elements cannot be other than actually up, ac•
tually down, etc. , and by definition, if nothing hinders, each element cannot
fail to be m<>lled by its appropriate actuality (actual up in the case of fire, ac•
tuai down in the case of earth, etc.)38 Let us consider the problem further.
Place, as Aristotle defines it, is the first motionless limit of that which
contains; as such place defines "up" and "down" within the cosmos and so
constitutes actual up and actual clown:
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Arisrode and Philoporws
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Aristotle's Physics and lrs Mediewl Varieâes
After reviewing and rejecting his opponents' views of the meaning of heavy
and light, Aristotle proceeds with his own account.46 Natural elemental
motion is again accounted for by place, which constitutes the boundaries of
ail bodies and so, in a manner of speaking, is their form.47 Hence, the nat·
ural, regular, directional motion of the elements is nothing but the element
being moved toward its own place as like is moved toward like.48 Clearly,
then, when a thing becomes light, as when air is generated from water, it
progresses into the upper region, where it does not become light but is
light.49 Such is motion, a thing being potentially and going "there," that is,
to its proper place; to arrive at its natural place is to be complete actuality. 50
In this sense, elemental motion is like any actualization of a potential by its
appropriate actuality.
But Aristotle notes that there is something special about the elements
and their motion. Here is the crucial point:
The source of change in the elements seems somehow stronger, or more in•
dependent, and so more like substance, than does the source of change in
other things. (Aristotle here compares the actualization involved in elemen•
tal motion to that involved in growth and in being cured; growth is motion
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Aristotle and Philoponus
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Arisrode's Physics and lts Mtdiewl Varieàes
cosmos as a whole determinate, because place constitutes its regions; the el•
ements constitute the natural component parts of ail things, both artistic
and natural, such that ail things are naturally and actively oriented toward
the appropriate natural place of their constituting elements.
Here then lies the meaning of "things that are by nature" for Aristotle.
Their being (and definition) is constituted by form, the thing as actual. 57 But
they are uniquely characterized by an intrinsic and active orientation of mat•
ter, the thing as potential, to that form. Thus, things that are � nature re•
quire no extrinsic mover, such as an artist, but contain in themselves their
5
own ability to be moved. 8 In the four elements, this ability to be moved, if
it bas a name, may be identified as "inclination," and this inclination is
nothing other than the very nature of the elements: their ability to be moved
by their appropriate place, that is, the determinative actuality that consti·
59
tutes the limit and boundary of the cosmos. We turn now to Philoponus
and bis commentary on Physics 2 and "things that are by nature."
,o6
Aristotle and Philoponus
107
Aristode's Physics and lu Mediewl Varieàes
possess soul and those which do not. Aristotle, after distinguishing nature
from other causes, lists things that are by nature, namely, "animais and their
parts, and the plants and the simple bodies, earth, air, fire and water"; but
he neither categorizes natural things, nor raises the problem of movers, nor
uses the word soul. The notion of inclination ( t,om\) never appears in Plrysics
2. Finally, Aristotle does not distinguish motion into locomotion, altera
tion, and increase, because his argument is not about motion or movers
properly speaking-it concerns the definition of things that are by nature.
lnterestingly enough, these categories of motion are crucial to his argu
ments that motion must be etemal and that "everything moved is moved
by something."70 Philoponus presumably imports them into his commentary
on Plrysics 2 because on his conception this argument is an argument about
movers and motion.
For Philoponus, the conception of nature as an intrinsic mover requircs
the division of natural things into besouled and unbesouled, so that intrinsic
movers may be identified for ail things that are by nature.71 As intrinsic mov
ers, soul and inclination constitute the ultimate defining mark for such
things. Because the problem of identifying a specific mover for natural things
never arises in Plrysics 2 itself, a fortiori neither soul nor inclination appears
as a mover in Aristotle's discussion. But because Philoponus conceives of na
ture as an intrinsic mover, they are immediately present in his commentary
on Plrysics 2.
Of course, as we have seen, Aristotle does identify things that are by
nature with form. But while for Philoponus this identification leads imme
diately to soul, for Aristotle it serves a different purpose. The identification
of nature with form shows first how art and nature are alike. Against this
similarity emerges the difference between natural things and artistic things,
and this difference defines what is unique about natural things: the dynamic
orientation of matter to form-a relation absent in artistic things because
matter is passive in relation to artistic form.
And indeed, if we read further in Philoponus's commentary, we shall
see that the issue at stake in things that are by nature is one of identifying
movers and how they move. ln one and the same stroke, the force of Aris
totle's contrast between nature and art disappears, and the active orientation
of matter to form is replaced by the agency of form as a mover. This point is
crucial to Philoponus's commentary and his concept of "things that are by
nature." We shall see it emerge clearly as Philoponus, commenting on Plrysics
2, develops his concept of nature and things that are by nature.
Philoponus, having identified nature as an intrinsic mover, now con
trasts nature with art, which he identifies as requiring an extrinsic mover.
Philoponus tells us that "ail things that are by nature have in themselves the
motion [i.e., the cause of motion) while things that are not by nature have
the cause of motion from without."72 For example, the artist is the cause of
1o8
Aristode and Pluloponus
the bed. 73 But rational soul ( it Â.OyLKfl ,pux1\) moves an animal, and this
principle of motion is not from without but is in the moved. 74
Philoponus now interrupts, as it were, his commentary on Plr,sics 2.1
in order to raise a technical problem about how rational soul moves body. lt
does so through the irrational soul, just as a sailor moves his ship through the
rudder. But the sailor is not a natural mover, intrinsic to his ship; rather, he
moves it as an extrinsic mover. If both the rational soul and the sailor use
instrumental causes, irrational soul and a rudder, and the sailor is clearly an
extrinsic (and so nonnatural} mover, why is rational soul, too, not an ex•
trinsic mover? 75 Even thought the rational soul uses an instrumental cause,
Philoponus argues, it nevertheless moves intrinsically. 76
This argument is telling. Like the easily recognizable example of the
artist and the bed, the example of the sailor and his ship are Aristotle's. But
they are drawn from the account of soul and accidentai motion in the De
Anima, not from the account of things that are "by nature" in Plrysics 2. 77
Furthermore, in the De Anima, when Aristotle considers the soul as a mover,
he faces the problem of how the soul can move the body and at the same time
be moved because of its location within body. And for Aristotle, within this
context the soul and the sailor are analogous: the soul is the mover of the
body as the sailor is the mover of the ship, and the soul is moved accidentally
by virtue of its location in body as, too, is the sailor in the ship. 78
But for Philoponus, the distinction between nature and art takes on a
new function, so that in his commentary on Plrysics 2.1, the soul and the
sailor are no longer analogous. No longer are nature and art identical insofar
as both are identified with form, and different only in respect to the relation
between matter and form. Rather, because nature is defined as an intrinsic
mover, the contrast between nature and art lies exclusively in the difference
between things having an intrinsic mover and those having an extrinsic
mover. lndeed, the technical problem concerning whether rational soul is
intrinsic or extrinsic when it uses irrational soul as the immediate mover of
body arises only because of the identification of nature as an intrinsic mover
in contrast to art, which requires an extrinsic mover. The fact that for Philo
ponus this problem-wholly absent from Plrysics 2-is immediately impli
cated in the distinction between art and nature shows how profoundly his
identification of nature as an intrinsic mover redefines the problem at stake
in Plr,sics 2. l.
Because Philoponus redefines nature as "an intrinsic mover," the con•
trast between nature and art functions quite differently for him than for Ar·
istotle. lndeed, the shift between Aristotle and Philoponus here illustrates
why the definition of "by nature" is so important to the history of Aristotle's
texts and their interpretation. As we have seen, for Aristotle nature is an
intrinsic ability to be moved, and matter is actively oriented toward its proper
form or actuality. As a result, a natural mover may be either intrinsic, as the
109
Aristode's Physics and lts Medieval Varieries
oak is the end toward which an acom is intrinsically oriented, or the mover
may be extrinsic, as the heavens are actively oriented toward an unmoved
mover who is separate from them. 79 ln both cases, the motion is natural,
because the moved contains within itself an intrinsic source of being moved.
Consequently, both the father and the artist are moving causes extrinsic to
the moved; but the father alone is a natural cause, while the artist does not
cause "by nature" but "by art."
For Aristotle, natural movers may be either intrinsic or extrinsic, be
cause what is "by nature," as opposed to "by other causes" such as art, does
not rest on the definition of nature as an intrinsic mover. Nature is an in•
trinsic ability to be moved, an active orientation of matter to furm. ln con•
trast, when matter is passive, as wood is passive in relation to the furm ofbed,
the thing is always artistic rather than natural. The locus of the difference
between nature and art lies in the varying relation of matter to furm: matter
actively desires furm in natural things but in artistic things is passive to furm
and hence requires an artist.
But because Philoponus has identified nature as an intrinsic mover, the
designation of movers as intrinsic or extrinsic is crucial to the question of
whether or not the mover moves "by nature" or "through other causes."
Varying relations between natamd movers and their respective moved disap•
pear: intrinsic means natural, and extrinsic means nonnatural (e.g., artis•
tic). Likewise, fur Philoponus, the varying relation of matter to furm (i.e.,
either active or passive) also disappears. Aristotle's active and passive orienta•
tion of matter to furm, as distinguishing. natural things from artistic, is re•
placed by Philoponus's distinction between intrinsic and extrinsic movers.80
Consequently, in his commentary it appears that between art and na•
ture there is no obvious difference in the relation of matter to furm. Herein
lies the origin of Philoponus's problem about rational soul resembling an ex•
trinsic mover when it uses irrational soul as its instrument. Rational soul,
operating through irrational soul, resembles an extrinsic cause if, and only if,
matter relates to ail movers, whether extrinsic or intrinsic, in the same way.
And indeed Philoponus's solution to this problem lies exclusively in a con•
trast between how a sailor works through the rudder to sail his ship and how
rational soul works through irrational soul to control the body. The ship and
the body seem exactly analogous-both are passive, neither contributes to
the resolution of the difficulty. Consequently, fur Philoponus, the difference
between natural and artistic things rests exclusively on the question of
whether the mover is intrinsic or extrinsic.
These relations are consolidated in the next paragraph of the commen
tary as Philoponus summarizes his position on things that are by nature:
110
Aristode and Philoponus
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Arisrode's Physics and lts Medieval Varieties
112
Aristode and Philoponus
body, rather than striving toward its form, is molded and governed by the
soul, which as its form descends into it; indeed, body has no being other than
that produced by the presence of soul keeping it together, preventing it from
descent into nonbeing.
Furthermore, although Philoponus mentions that nature is a govern
ing power for the unbesouled as well as the besouled, soul dominates this
summary of things that are by nature and emerges as the primary mover of
natural things. ln the De Caelo, Aristotle daims that the motion of the el
ements is a superior motion both because their matter seems to be nearest
substance and because they exhibit locomotion. We shall see how Philopo
nus handles the problem of the inanimate elements in a moment: as the in
trinsic principle of motion in unbesouled things, inclination will be similar to
soul, just less distinct, less clear. ln this sense, for Philoponus, soul serves as
the central concept, or mode(, of the intrinsic mover making a thing to be
"by nature."
Again, the account resembles Stoic accounts of the world. According
to the Stoics, the world is constituted by a series of internai tensions that
produce extension as a sign of their presence; these internai tensions become
progressively weaker as they become more remote from soul. This notion of
descending degrees ultimately originates in Plato's account of the world. 97
For Plato, according to his account in the Timaeus, the Demiurgos brings or•
der out of chaos by instilling soul into the world. 98 But when it is time to
furm truly mortal things, the Demiurgos hands over to lesser gods the re
mains of the proportions from which eternal becoming was formed.99 The
same causes are at work for the mortal as for the immortal effects, but to a
lesser degree, with the result that mortal effects exhibit the same relations
(and can be analyzed in the same way) as immortal effects, but the relations
are weaker, less long lasting, less knowable, and so forth. 100
Finally, although Philoponus does not explicitly evoke the language of
"presence," it seems to underlie the relation of soul to body throughout this
summation and therefore requires consideration. For Aristotle, the require
ment of motion is contact between mover and moved. Presence, such as the
presence of soul to body, holding together its being, replaces this requirement
with another of a radically different order.
For Aristotle, contact means that mover and moved are different but
touch at some extremity-nothing intervenes between them. 101 But "present
throughout" means that the mover is everywhere permeating the moved.
And such seems to be the relation of soul to body in Philoponus. ln this
mode( of nature as an intrinsic mover, the moved depends on the presence of
soul as an intrinsic mover to grant not only motion but being itself insofar as
body has being-the presence of soul prevents body from sinking into "non
being." But such a concept, "presence," derives from Plato's notion of im
material form causing what is formed, or soul causing body; it is also
llJ
Arisrode's Physics and lrs Mediewl Varieàes
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Aristotle's Physics and lts Medieval Varieaes
The physicist, Philoponus argues, must know place, because the place
of each of the elements. is defined according to its nature. If, he says, (part of)
the task of the physicist is to understand physical bodies, and each of the
elements is defined according to nature, then it is impossible to know these
bodies without knowing the motion that is theirs according to nature; but
this motion in turn requires that we know the place according to each in
116
Aristotle and Philoponus
Aristotle mentions the natural bodies (i.e., the elements) here only to pro
vide evidence about place, the proper subject of the argument: place is-it
can be identified in six regions-and exerts some sort of power. (Of course,
we have already discussed the sense in which place "exerts a certain power,"
namely, renders the cosmos determinate and so serves as the actuality for the
117
intrinsic potency of the elements.)
But according to Philoponus, after Aristotle shows "that place is," he
shows not only that it is "but also that it has some natural power and
difference."118 This smalt addition "and difference," together with Philopo
nus's own definition of nature, is crucial. If Philoponus's introduction to
Plrysics 4 characterizes the problem of place generally for the physicist, this
argument specifies the problem of place for the elements.
Philoponus develops his own notion of the "natural power and differ
ence" of place by introducing a new topic found neither in Plrysics 4 nor in his
own commentary on it thus far. But we recognize it from the commentary on
Plrysics 2: inclination.
And the attempt [i.e., to show not only that place is but also that
it has some natural power and difference] is from the inclination
[pom]] of the natural bodies. For each, he says, of the natural
bodies is carried when unhindered to some determined place, for
example light things up and heavy things down, and when either
light things are carried down or heavy things up, they are carried
119
contrary to nature and by force.
u8
Aristotle and Philoponus
Several points stand out here. None of them derives from Aristode. ( l)
Philoponus emphasizes the elements as moved by nature, or sent according to
nature to place, which, he says, is yeamed for; again, inclination is the nat
ural mover of the elements. (2) Place has difference because "these things"
(i.e., the elements carried up, down, etc., by their intrinsic inclination) dif,
ferentiate it. (3) The natural power of place is connected with its being aimed
at and able to receive body. We must briefly consider these three points.
( 1) Philoponus clearly presupposes his account from Plrysics 2 in which
the elements by nature possess an intrinsic mover (i.e., inclination), which
moves the natural body and so is the cause of motion to the proper place.
Consequently, place cannot function as actuality or as a determining prin,
ciple, and Philoponus's account of elemental motion requires not place but
inclination as the intrinsic mover of the elements. W hen the elements are
said to move "by nature," that nature is the mover intrinsic to the elements
and excludes reference to place.
(2) I argue above that for Aristotle place and the elements fit together
as actually and potentially up, down, etc. For Philoponus, since the account
of nature as an intrinsic ability to be moved has been replaced by an account
of nature as an intrinsic mover, place and the elements can no longer be re,
lated as act and potency. Place, as it emerges here in Philoponus's account,
is just that concept required by the notion of nature as an intrinsic mover of
physical body. The intrinsic mover of the elements, that is, inclination up or
119
Arisrode's Physics and lts Mediewl Varieties
down for light and heavy things, respectively, moves the elements up or
down; this in turn determines place. For ail heavy things, the inclination is
toward the center, which makes the center down. Thus, place does not
emerge as the actuality of the elements, themselves potentially up or down;
rather, "down" is where heavy things are carried by their intrinsic inclina•
tion, and the center of the cosmos is "down" becawe heavy things go there.
Place is not the determinative boundary of the cosmos, but is itself deter•
mined by things that aim at it and move intrinsically, according to nature, as
Philoponus has it.
Indeed, Philoponus could hardly be more explicit: the inclinations in
natural bodies differentiate place as up and down. Consequently, far from be
ing a principle of determination, place itself is determined by moving bodies
(either the body itself or inclination as the intrinsic mover). This point re•
verses Aristotle's view of the cause/effect relation between place and the el
ements. lt requires some consideration before we turn to the third point,
place as yearned for and able to receive the elements.
When Philoponus comments on Aristotle's next argument, namely,
that the differences of place are not just relative to us, he repeats this point:
"For we call 'down' wherever heavy things by nature are carried, and 'up'
wherever light things."121 Place, then, does not differentiate the cosmos but
is differentiated by "these things" (i.e., what goes up, down, etc.). Philopo•
nus agrees with Aristotle that the cosmos-and place within the cosmos
is differentiated; but the cause/effect relation producing this differentiation
is reversed.
For Aristotle, place as a limit differentiates the cosmos as any limit dif•
ferentiates what is limited. But for Philoponus, place is differentiated because
the natural bodies that move by nature define "up" or "down." Thus, for Ar•
istotle, fire goes up and earth down because place as a determinative limit
moves them as any actuality moves the potency respective to it; for Philo•
ponus, place is determined to be up or down because fire or earth always
move there by virtue of an intrinsic mover (i.e., inclination up or down).
But natural body in and of itself is molded and governed by its mover.
Therefore, it cannot be body as such that differentiates place. What differ•
entiates place is the intrinsic mover of the elements, inclination up or down
that, as an intrinsic mover, determines where each element goes and thus
determines place as up or down. As Philoponus says, in heavy things, the
inclination is always toward the center. The power attributed to place per•
fectly reflects its demotion from cause to caused. Each of the elements moves
toward its natural place, so that according to nature, the place for each is
what is "aimed at" or "yearned for." This being "aimed at" is associated with
the power that place by its nature possesses. 122
(3) "Aimed at" or "yearned for" in this context can only mean a power
to receive body moved by its intrinsic mover, inclination. This notion follows
120
Aristotle and Philoponus
CONCLUSION
121
Arisrode's Physics and lts Medieval Varieties
ary of the cosmos, constituting actual up, down, and middle toward which
the elements are naturally and immediately oriented by virtue of their re
spective inclinations, that is, their respective intrinsic abilities to be moved;
but for Philoponus place is extension, which is itself determined by the mo
tion of the elements-a motion produced by inclination as an intrinsic
mover, the very form of the elements.
I would like to close with a brief look at two modern comments on Ar
istotle's account of elemental motion. The first is a note from the new Oxford
translation of Plrysics 2 by Charlton, and the second is from Waterlow's Na
ture, Change, and Agency in Aristotle's Plrysics. While neither of these com
mentators indicates any acquaintance with Philoponus, each shares
something of the logic of bis position.
Charlton says of the elements, using earth as his example:
Fire does not happen to move in the direction that we call 'up'.
lt moves thus because that direction is intrinsically different from
122
Aristotle and Philopo,uu
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Arisrode's Physics and lrs Mediewd Varieâes
124
Chaprer 6
ALBERTUS MAGNUS:
ARISTOTLE AND NEOPLATONIC PHYSICS
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Arisrode's Physics and lts Medieval Varieties
argue that the rhetorical and logical structure of the commentary provides the
first moment in which Albert makes Aristotle's physics his own; his substan
tive solutions to problems within physics, such as the problem of elemental
motion, occur within this structure and are profuundly affected by it. lndeed,
I shall argue that Albert shifts the problem of the elements from Aristotle's
question of why they move to the quite different question of how they move.
Consequently, the problem of elemental motion not only presents a precise
substantive issue within physics but also raises the broader issue of how Albert
thinks of physics within the context of a commentary on Aristotle's Plrysics.
As a form, the commentary is at once a primary and a secondary
source, presenting Albert's own thought and his reading of Aristotle's Plrys
ics. The tension between Albert's authorship and Aristotle's authority marks
Albert's physics, as indeed it marks much of Aristotelian science insofar as
that science was conducted in the context of commentaries on Aristotle's
works. Hence, before tuming to the content of Albert's commentary on Ar
istotle's physics, we must consider its form.
Although in his Plrysics Aristotle neither mentions God nor relates
physics to theology, Albert announces that the first purpose of his commen•
6
tary on the Plrysics is to praise God. The theological issues that Plrysics 8
raises for Albert thus constitute a strong vested interest throughout his corn•
mentary. For example, Aristotle' s arguments for the eternity of the world
seem to oppose the creation of the world by God, and, for Albert, this op•
position requires a resolution within the commentary on Plrysics 8. Albert
achieves this resolution by developing, completing, and correcting Aristot•
le's arguments within his own Christian and Neoplatonic commitments. 7
Even a problem such as elemental motion, which would appear to rest
squarely at the heart of physics, is profoundly affected by the presence, for
Albert, of these theological issues.
But even as Albert develops Aristotle's argument within his own theo
logical commitments, he also intends to explain Aristotle, and he unambig•
uously attributes responsibility fur the conceptions and conclusions of the
,,
commentary to the "dicta antiquorum Peripateticorum. s And the Plrysics as a
text serves an unmistakable function: it presents and orders the problems of
physics to be considered by Albert within his commentary. 9 Albert fullows
the order of problems given in the Plrysics and writes as many books in his
commentary as there are books in the Plrysics itself. But within the commen•
tary he inserts a new rhetorical structure. He divides each book into tracta
tes, which in turn are divided into chapters. Unlike the books of the
commentary, the tractates, and ultimately chapters, have no foundation in
the structure of Aristotle's works as we know them. 10 But these tractates furm
the crucial rhetorical structure of Albert's commentary.
The origin of the tractate as a form is obscure. 11 lt appears in the
Mishna, where it rubricates the laws given in the Bible and whence it passes
126
Alberncs Magnus
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Arisrode's Physics and lrs Mediewl Varieties
shall argue, quite different from Aristotle's and, as a result, redefines both
Plrysics 8 and physics as a science. No problem in physics, including elemen
tal motion, remains untouched by this redefinition that originates in a theo
logical digression.
ln Tractate I, Albert's analysis of Aristotle's arguments for the eternity
of time and motion follows the opening digression. For Albert, this initial
proof serves a larger purpose, namely, it sets the stage for a proof of a first
mover in the later tractates. 17 Again, we shall see how Albert redefines first
the structure and then the substance of Plrysics 8.
Theological digressions close Tractate I and present Albert's first treat•
ment of the elements and their respective motions. The elements are first
created and then ordered to their proper ends by God acting through His free
will. Because Albert considers the elements within a theological digression,
the importance of theology for a specific problem central to physics appears
in sharp relief. Albert intends to maintain both the primacy of God as Cre
ator of the universe and the efficacy of natural causes. Tractate I establishes
these two causes and affirms God's primacy; Albert's second account of ele
mental motion, which appears in Tractate Il, talces up the problem of natural
causes and so presents Albert's physics, properly spealcing.
ln Tractate Il, we find Albert's solution to the problem of the natural
cause of elemental motion. A thing's generator is the essential mover of the
element, because it connects the initial created subject matter of the element
with its divinely ordained end. In short, within the domain of physics, Al
bert redefines the problem of elemental motion to meet his prior theological
commitment to the doctrine of a creating God.
The problem of elemental motion provides direct access to Albert's
theological and philosophie commitments as expressed in his commentary on
Plrysics 8. 1 shall analyze Albert's account of elemental motion both in the
digression of Tractate I and in Tractate Il (i.e., Albert's direct commentary
on Plrysics 8) and in conclusion reflect on Albert's account as well as the
relation between Aristotle's physics and Albert's "Aristotelian physics."
128
Albertus Magnus
world (Genesis) and the efficacy of natural causes in nature (Plrysics 8). I shall
argue that in Tractate I of his commentary on Plrysics 8, Albert resolves the
(apparent) conflict by inserting into Aristotle's argument Neoplatonic con
cepts of nature, motion, and finally physics itself. Although Tractate II does
not mention God, we shall see that it presupposes both the theology and the
Neoplatonism from Tractate 1. ln this sense, the theological issues raised for
Albert by Plrysics 8.1, and his Neoplatonic solution of them, determine his
account of nature and elemental motion. We turn now to Tractate I.
Albert's commentary on Plrysics 8 opens with a digression concerning
both the purpose of Plrysics 8 and the question of how God precedes the
world. The purpose of Plrysics 8, Albert says, is to investigate "if there is some
perpetual motion which is a cause of the perpetuity of motion in general."18
Any demonstration of a first perpetual motion must show both that it is one
and that it is circular, because only such a motion can cause perpetual mo
tion in inferior things. 19
But, Albert immediately asserts, to call the first motion eternal does
not imply that God and motion are coeternal. Here is Albert's first problem
with the argument of Plrysics 8: because they are both eternal, God and the
first perpetual motion look alike and so might be confused. 20 Albert's solu
tion to this problem reveals the limits of physics as he defines it.
Citing Boethius's De Consolatione philosophiae, Albert distinguishes the
eternity of motion from God's eternity. God precedes motion not by time but
by eternity, because God is prior to the world both as its cause and by an
eternal duration. 21 As the creator of the world, God is absolutely prior to it,
and His eternity is completely indivisible: "God precedes the world by dura
tion with eternal duration that is unceasing and in every way immutable."22
In contrast to God, motion is eternal not as an unceasing duration,
but as a set of parts succeeding one another without beginning or end. The
eternity of motion is not prior to time but is coextensive with time; that is,
there is no time, past or future, when there was not, or will not be, motion.
Unlike God's eternity, the eternity of motion is neither prior to its parts
nor indivisible. ln short, God's eternity is not only prior to that of motion
but of an entirely different order. Consequently, although God and mo
tion are both eternal, God's eternity is that of a perfect causal one, while
motion's eternity is that of a perpetual set of parts, itself an effect requiring
a higher cause. 23
For Albert, this distinction defines the limits of physics as a natural
science. W hile it is true, he says, that we intend to prove that motion did not
begin and will not end, nevertheless, it is impossible for physics to prove any
thing except what falls under its principles as physics. 24 And the eternity with
which physics deals is that of motion, not of God. As physicists, we must not
spealc of those things that are above physics and that reason is not able to
comprehend, such as creation and the mode of creation of ail things. 25
129
Aristotle's Physics and lts Mediewl Varieties
130
jected by Aristotle), which reaches Albert through Neoplatonic intermedi
aries and may be speculatively identified as Avicenna's separate intelligences.
For Aristotle, motion and perfection, although closely related, remain
distinct. Motion is the actualization of the potential qua potential by what is
actual.35 Actuality provides the definition of what is potential, while the po
tential "desires" its appropriate actuality. Perfection, stricdy speaking, is the
actuality itself toward which a potential develops and for which it yearns.36
On Aristotle's account, motion must be eternal, because potency is never
neutral to actuality, and actuality never fails to be efficacious; on contact
with proper actuality, potency is always moved by that actuality as its defi
nition, end, or perfection.37 For this reason, the identification of potency
able to be eternal (i.e., circular locomotion) and its proper actuality, a first
unmoved mover without magnitude, parts, or location, explains why mo
tion in things must be eternal. 38 Finally, because potency is moved while
actuality moves, even the self-mover falls under the principle "Everything
moved is moved by something," and a self-mover cannot as such be a first
source of motion.
Plato and his followers conceive of motion quite differently: motion is
perfection granted to body by soul, when it cornes to be present in a body.39
Aristotle and Neoplatonists both use the word perfection, perhaps because
they agree that motion is an effect requiring a cause or source. But their con•
cepts of perfection, motion, and causes are entirely different. For Plato and
the Neoplatonists, as a perfection motion must be attributed entirely to soul
as its cause; physical motion is merely the by-product of spiritual perfection
present to a body, which, far from yearning for soul, is in itself motionless and
lifeless.10 On this view, the yearning of potency for form disappears; motion
in things immediately implies (and is entirely accounted for by) the presence
and necessity of perfection, identified as soul.41 lndeed, being a self-mover is
the very definition of soul, and Plato twice argues that soul is the first source
of ail motion in the cosmos.42
When Albert first associates motion, "a kind of life," with soul and
then defines motion as a "perfection," his concept of motion seems to orig•
inate not in Aristotle but in Neoplatonism and ultimately Plato. For Albert,
perfection in the moved functions as a formai characteristic on a Neoplatonic
mode(; that is, when detected in the moved, it immediately implies the ne
cessity of an independent perfect formai cause.43 ln short, being perpetual is
a perfection that belongs primarily and absolutely to the first cause and is in
things as an effect only via the presence of this cause. Consequently, there is
but one perfection, namely, the perpetuity of the cause, which can be seen
in two ways, either directly in itself as a cause or secondarily in the effect,
because it is brought there via the presence of the cause. This view is re•
flected in Albert's language; he speaks not of motion in things, but of "some
perpetual motion that is a cause of the perpetuity of motion in general".44
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Arisrode's Physics and lis Mediewd Varieâes
For Albert, perfection is in body but does not properly belong to body,
and therefore the presence of perfection in body necessarily implies an inde
pendent perfect cause. 45 He calls the first cause perpetual "according to
substance," but his meaning derives from the Neoplatonic concept of par
ticipation: the presence of a perfection in body immediately implies a source
of that perfection absolute in itself. And for Neoplatonists, because soul is
the perfect identity of mover and moved, soul alone serves as the first source
of motion to all moving things. 46 Motion, on this view, is a perfection
present to body because (and only because) soul is present to body. 47
Even at this early point in the commentary, Albert appears to replace
Aristotle's philosophie commitments with his own. Aristotle's logos has been
replaced by four ttactates, his single thesis has been replaced by a set of four
theses. Aristotle's main thesis opens Plrysics 8, while Albert's four tractates
lead toward, and conclude in, the goal of the argument. Physics as a science
has been subordinated to theology, and now motion is neither eternal in
things nor an actualization of the potential; rather, it is perpetual motion in
general, a Neoplatonic perfection.
Just as a digression precedes the arguments concerning the eternity of
motion, so too a digression, Tractate 1, 4, follows them. Albert raises the
question of how motion is eternal and how not, and the (for him) implicit
question of the relation of physics to theology. He argues that proofs for eter
nal motion have nothing to do with creation ex nihilo but concern only gen
eration; here Aristotle is right-nothing cornes from nothing, nihil nihil fit per
genemtionem. 48 Postponing the problem of generation itself to Tractate Il,
Albert now explains creation as presupposed by generation. Since the ele
ments are first created and then generated, this account constitutes the first
moment of Albert's solution to the problem of elemental motion. ln it we
can see why a problem in physics requires a prior theological treatment.
To explain creation, Albert distinguishes between first form and sec
ond form. 49 First form, he daims, must be produced by a first efficient cause.
Furthermore, because no form precedes it, and because it is not inchoate in
matter, it cannot be brought out of matter. Therefore, Albert concludes,
through an act of the first efficient cause, first form itself is produced from
nothingness; nothing more can be said, because at this point we find our
selves in a subject that belongs to first philosophy, that is, creation ex nihilo
by God. 50 Hence, Albert asserts, the world began not through generation,
but through creation of first form out of nothing by a first efflcient cause.
Two features of this argument stand out. (1) Albert identifies efficient
causality with God and His act of creation, that is, the production of some
thing from nothing. Efficient causality in this sense is distinct from natural
causality and lies outside of nature. 51 Historically, the origin of this concept
lies in Christian Neoplatonism. 52 (2) Albert distinguishes first form from
second form, which is produced through generation and will be explained in
132
Albertus Macnus
Tractate II. While first form has no form preceding it, Albert will later ex
plain that second form is preceded by first. This distinction, central to Al
bert's account of elemental motion, is wholly foreign to Aristode. Rather,
Albert's concept of first form derives via Augustine and Avicenna from Neo
platonic rationes seminales, "seminal reasons" present in matter and awaiting
second form.
ln Tractate 1, 5, Albert takes up Aristode's arguments for the etemity
of time; then, as we might expect, he inserts a digression (Tractate 1, 6),
arguing first that these arguments are only probable and then explaining the
sense in which time begins through creation.53 The chapters following this
digression first argue that ·motion is incorruptible in future time (Tractate I,
7) and then refute views opposed to Aristode's, first those of Anaxagoras and
Empedocles (Tractate I, 8) and then unnamed "sophistic arguments" (Trac
tate I, 9). The last chapter of this tractate to deal direcdy with Plrysics 8
(Tractate I, 10) gives "solutions of the enumerated arguments" (i.e., the ob
jections raised in Plrysics 8.2). With these solutions, for Albert, the question
of whether motion is etemal is complete.
Even though Albert does not call these chapters "digressions," he in
cludes in them issues that arise for Aristode either much later in the argu
ment or not at ail. For example, in regard to animate motion, Albert
distinguishes a prime mover, which he identifies as the intellect, and moved
movers such as phantasms, appetite, and power in the muscles of the animal;
he discusses both the relation between soul and body, and a man and the
elements of which the body is composed. 54 He also introduces, although
without developing it, the distinction between self-motion, which he calls
being "moved internally," and motion produced by another, or being "moved
externally."55 For Albert (unlike Aristode), these issues are immediately en
tailed by the logic of the argument. This logic rests on his concept of motion,
which divides soul and body, associates motion, life, and soul, and so seems
to understand ail motion as ultimately dependent upon soul.
56
For Albert, Aristode's proof that motion must be etemal is complete
at the end of Plrysics 8.2.57 Consequendy, the remainder of Plrysics 8 pro
gresses to higher arguments-those providing the theses of Tractates Il, III
and IV. As we shall see, in Tractate II Albert investigates the "next thesis"
of Plrysics 8, that is, "the properties of motion according to the consideration
of a first mover."
B. But although Aristotle's arguments are complete, Albert's are not: five
digressions, including Albert's first extended treatment of elemental motion,
complete Tractate I. The first two of these digressions (Tractate I, 11-12)
concem sophistic arguments against the view that motion in things must
be eternal. ln both, Albert relates motion to its first mover and ties God to
the problem of intellect and the first intellect. 58 The last two of the five
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Albertus Magnus
the celestial sphere and by place; a certain distance from the orbs generates
66
fire, another distance generates air, and so on for water and earth, too. ln
deed, nothing diversifies matter except what terminates and perfects it,
namely, second form.67 So, Albert concludes, when Aristode say s that fire
naturally goes upward or is up, the relative distance of fire from the celestial
sphere is the form operating within nature.68 Distance diversifies the ele
ments (e.g., up for fire and down for earth) by granting to matter and first
form its second form, which is its perfection, and ultimately, its definition:
fire is what is up.
Thus, according to Albert, two distinct causes operate for all created
things, including the elements. God first creates, and thereby gives, all
things matter and first form-He brings them into being out of nothingness.
Only through God's efficient causality do things first become proper subject
matter for natural causes.
Secondly, natural causes operate through generation. Although a full
account of the generator as a natural cause lies ahead in Tractate li, it ap•
pears here in relation to divine causality. By definition, generation requires
creation, because it requires the subject matter given by creation; so, as a
cause, generation (and thus the generator) is less perfect than, and depen
dent upon, God. Generation diversifies the first created subject matter (first
form plus matter) by providing it with its end and perfection. This diversi
fying end, or perfection, is also properly called "form," namely, "second
form."
Thus, it appears that all created being, even the elements, is subject to
both divine and natural causes. Divine causality operates ex nihilo, while
natural causes both presuppose creation and produce natural things through
generation and second form. In this sense, these two causes, God and the
generator, as well as their effects, remain distinct. Like all created being, the
elements are both created and generated.
But serious problems remain. Each created thing receives its proper end
and perfection from its generator, which thereby diversifies and completes
the subject matter created by God. Thus this account of natural causality pre
supposes not only the subject matter created by God, but also second forms
and the rich diversity of such forms found in nature. At this point they re
main unexplained. Furthermore, the generator, not God, perfects created
things. In this sense, second forms appear to be more important than the
subject matter that God creates. What is the origin of second forms, and as
perfecting created things are they more important than God?
Albert's answer is straightforward. Second forms, the ends and perfec
tions of ail created things, must be created and, furthermore, created in re
lation to first form.69 When the elements are produced, they must be
produced either through necessity, as heat from a fire, a figure in a mirror, or
footprints in dust, or they must have been produced through knowledge, will,
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Aristotle's Physics and lts Mediewu Varieâes
136
Albertus Magnus
own free will creates first form and matter as well as final ends; He then or
ders them according to His plan.74 As chaos and the etemal model must be
brought together by God for Plato, so, it seems, created subject matter and its
perfection must be ordered together by God through His free will for Albert.
(However, Plato's Demiurgos is not a Christian God and does not create ex
nihilo-he informs chaos with models; nor does he act out of free will
rather, he could not do otherwise.) 75 Albert may use Aristotle's language of
generation and the generator, but in his account, the generator performs a
uniting role analogous to Aristotle's artist and Plato's Demiurgos.
(2) For Albert, motion, as we noted above, is not an essential devel
opment of a thing from potency to actuality; rather, according to Albert, the
generator produces motion by bringing the perfection of second form to first
form and so connecting two things that go together not "by nature" but
through divine ordination alone. In the Timaeus (and Symposium), soul is
the bearer, or messenger, of perfection into matter, and in Albert's earlier
discussion of motion we saw that for him motion is intimately connected to
soul. This parallel will reappear in Tractate Il.
According to Aristotle, proper actuality (Aristotle's perfection) must
always be efficacious, so that on contact with it, potency cannot fa.il to be
actualized. Hence, for example, Aristotle faces the special problem that mo•
tion in the elements does not always occur, even though actuality is always
present. The resolution of this problem lies in the notion of a hindrance
bloclcing the relation of potency to actuality-remove the hindrance, and
motion immediately occurs.
But for Albert, perfections, or ends, cannot be a cause of motion (at
least not in Aristotle's sense), because first forms and their ends (i.e., second
forms) are not intemally related. Motion, as Albert conceives it, requires a
cause that conjoins two things that at the level of nature are unrelated.
Hence Albert conceives of the generator as the bearer of perfection (i.e.,
ends preordained by God) into an initial created subject matter. Thus, Al
bert's definition of motion and his definition of the causal role of the gen•
erator in the world are related and in both moments oppose Aristotle's
concepts of nature and things that are "by nature."
(3) According to Albert's account, ends, or perfections, are separate
from initially created first form. For this reason, they must be related through
God's ordination and free will. For Aristotle, matter is nothing other than a
relation to form as actuality; indeed, matter's very nature is "to be aimed at
form." Thus, an end (or form) specifies matter in the sense of developing a
directed possibility into a specific actuality, and no malcer or third cause in
addition to matter and form is ever needed. Consequently, form is the form
of a thing, rather than form in a thing. Finally, place serves as the actuality
of the elements, and Aristotle explicitly denies that distance from its proper
place can differentiate the nature of the simple bodies.76
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Aristode's Physics and lts Medieool Varieiies
Albert separates ends (second forms) from created first forms in order
to meet a theological requirement: form as end and perfection must be cre
ated by God according to a rational ideal, if the account of God's creation is
to be complete. So too with Albert's first forms-their creation is required by
his theology. But although Albert's immediate motive may be theological,
the separation of end from initial subject matter works together with his
philosophie conceptions of motion and physics as a science. Aristotle's na
ture is replaced by created being, while his concept of motion as actualization
is replaced by motion as a perfection granted by one thing to another. As we
shall see in Tractate Il, first and second form are essential to Albert's physics,
especially his account of elemental motion. ln short, the concepts that serve
Albert's theology will also serve his physics. Once we see Albert's physics in
Tractate li, we can conclude by considering the broader issue at stake here
and throughout the commentary on Plrysics 8: Albert's conception of physics
as working together with theology.
(4) Finally, Albert conceives of natural motion as "generation," that
is, the conjoining of first and second form 50 that second form diversifies ini
tially created first form. What is the difference between second form diver
sifying first form, à la Albert, and form specifying matter, à la Aristotle? To
specify matter is to draw actively oriented possibility toward its single unique
end; to diversify first furm is to direct an initially created subject matter to
one of a wide range of possible ends. 77 Consequently, initial created subject
matter (i.e., first form) is not ordered intrinsically to its end; rather, it is or
dered to its end only by divine ordination and free will. ln this sense, first
form, its relation to second form, and the need for a generator resemble not
Aristotle's physics 50 much as Plato's physics, with its chaos, separate forms,
and a Demiurgos who conjoins them.
Within the context of this theology, Albert explains elemental mo
tion. The second form, and hence terminus, of the elements is generated by
the perfection of the celestial sphere, which, by means of the varying dis
tances of the elements from the sphere, produces both elemental motion and
the diversity of these motions.78 Aristotle denies this view. On his account,
fire goes up, and earth down, because each is moved by its respective actu
ality, its natural place. Plato's account does not mention such distances at
ail.79 The origin of Albert's account of elemental motion may be Avicenna's
Meraphysics. 80
Before turning to the physics of Tractate li, we must consider the re
lation between physics and theology here in Tractate I and the implications
of that relation for Albert's physics. Much of the "causal work" that actuality
does for Aristotle's physics, for Albert is done by God. That is, actuality's role
for Aristotle as the immediate end, the very definition, toward which matter
is actively oriented is for Albert performed by God's preordination and free
will in ordering first form to second form. Furthermore, for Aristotle the
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139
Aristotle's Physics and lts Medie1ial Varieâes
In Tractate li, 1 and 2, Albert briefly states the purpose of the inves
tigation that begins in Physics 8.3: to consider moved things in order to find
their cause, a first mover. But first, two false views, namely, that ail things
are at rest and that ail things are in motion, must be rejected. Although Ar
istotle and Albert explain motion differently, they agree that it is both eter
nal and the effect of a first cause; these "false views" are incompatible with
this view of motion. 91
Albert's constructive argument now begins and from the outset differs
strikingly from Aristotle's. Aristotle recasts an objection to the thesis that
motion in things must be etemal and solves this objection by displaying the
structure of the cosmos. Within this argument, he argues that "everything
moved is moved by something" and identifies a mover for ail moved things,
induding the elements.
But for Albert, Physics 8.4-6 reaches the first cause of motion by work
ing inductively from motion to its first cause, unknown, indeed unknowable,
except through such an argument.92 Hence, he reads Physics 8.4-6 as the
first of two arguments explaining "the way by which" things are moved so
that they must have a first mover.93 Consequently, the logic of the argument
progresses from an effect to its cause, and its domain includes both things
exhibiting motion and a first mover that causes motion; the problem of the
elements is not one of identifying its mover, but of explaining "the way by
which" this motion occurs. 94 In short, treating the argument as a proof of a
first mover in a single stroke shifts its logic, its domain, and the problem of
the elements at stake within it. 95 The argument of Tractate li, 3-4 reveals
the full force of this shift.
ln Physics 8.4, we may recall, Aristotle distinguishes essential from ac
cidentai motion, takes up essential motion, and divides it into four catego
ries: self-moved, moved by another, natural, and violent. 96 Albert arranges
these categories into a hierarchy of motions according to a first cause, and he
treats them as progressive. Here we leave Aristotle entirely, as Albert devel
ops his own physics and exhibits the power of the commentator over his
authority.
Albert specifies accidentai motion as lowest in the hierarchy, iden
tifies essential motion as motion by another, and then defines it: the mover
and moved always differ in definition (and in the case of the elements, they
differ in being, too). 97 ln the highest category of motion, we find self-moving
soul, which is never moved essentially and is unable to be so moved; if
soul were separate from body, then it would not be mobile in a physical
sense, because there is no physical motion where there is no quantity. 98 In
this sense, self-motion is distinct from, and higher than, essential motion
by another.
Arisrode's Physics and lts Medimd Varieâes
This hierarchy, which is entirely absent from Plrysics 8.4, orders motion
within Albert's argument and locates elemental motion within that order.
Accidentai motion is entirely extrinsic to the being of both mover and moved
and, so, is the lowest motion; furthermore, accidentai motion is more know
able to us, and we work through it in order to arrive at essential motion.99
Essential motion by another in tum is manifestly inferior to self-motion.
Therefure, we should first analyze accidentai motion and then motion by an
other, including the elements, and finally self-motion, so that we may
thereby ascend from the less knowable to the more knowable.
And Albert in fact proceeds from accidentai motion to the next higher
kind of motion, essential "motion by another." The highest motion, the true
self-motion of soul itself, remains for Tractate Il, 5 and 6, (i.e., Albert's read
ing of Plrysics 8.5-6). Self-motion in its turn implies a first mover (Tractate
Il, 6), and only with this mover does Albert's argument close. In this way,
the overall purpose of Tractate Il, namely, to worlc from motion to its first
cause, is both served by and reflected in Albert's hierarchy of motions.
The elements present essential motion caused by another. In Tractate
Il, 3 and 4 Albert considers this motion, which is intermediate in the hier
archy. As essential, it is superior to (and more lcnowable than) accidentai
motion; but as motion by another, it is inferior to (and less lcnowable than)
soul's self-motion.
Albert subdivides motion by another into two types. ln the higher sub
division, animal motion, mover and moved differ in definition alone; in an
imais, the mover (soul) is the form and perfection of the moved (body), and
so mover and moved are identical in being. 100 But in the lower subdivision,
elemental motion, the mover and moved differ not only in definition but also
in being. Consequently, ail motion by another, whether animate or of the
elements, requires that mover and moved diff'er in definition, and this dif
ference defines motion by another. ln the case of the elements, mover and
moved also diff'er in being, and for this reason they are the lower subdivision
of motion by another. 101
The position of the elements within the hierarchy of motions defines
the very problem of elemental motion. When Albert arranges Aristotle's
categories of motion into a hierarchy that progresses to a first mover, the re
lation between mover and moved also becomes progressive. At each stage,
the mover and moved are more closely related until we reach the self-identity
of soul. At the lowest moment in the hierarchy, accidentai motion, the re
lation between mover and moved is entirely extrinsic to their formai
being. 102 Motion by another, the second stage in the progression, is essential
and, therefure, the relation between the mover and the moved is intrinsic to
them. Within this moment, animal motion is higher, because in it mover
and moved diff'er only in definition, while for the elements mover and moved
differ in both definition and being. Ultimately, in the self-moving motion of
soul, there is only one being and one definition, that of soul itself, which as
a self-mover is wholly self-identical. Thus, the logic of Albert's argument as
progressing from motion to its first mover, unites with his hierarchy of mo
tions and his treatment of mover/moved relations as progressively more
self-identical. 103
Within the hierarchy of motion, the elements constitute a special
problem. Their motion is essential, and so must be intrinsic; but, unlike an
imal motion, mover and moved in the elements differ in both being and
definition. 104 Consequently, the difference that locates elemental motion
within the hierarchy of motions also defines the problem of elemental motion
for Albert: how does a mover that differs from the moved in both definition
and being, move it essentially, that is, intrinsically?
The problem of elemental motion here is entirely different from Aris
totle's. For Aristotle, there is no hierarchy of motions from accidentai to self
moving. lndeed, there is no such thing as the self-moving motion of soul
apart from body. Furthermore, as potency and actuality, mover and moved
must be identical in definition and in being: both the actuality and the def
inition of an acorn are oak. Consequently, the problem of relating two things
differing in being and definition never arises in Aristotle's account of nature.
Indeed, Aristotle faces the problem of why motion does not always occur
not that of how mover and moved relate so that motion ma, occur.
Albert must account for how motion can occur when mover and
moved differ in definition and being. Before answering this question, Albert,
like Aristotle, rejects the view that the elements are moved intrinsically by
soul. Because they both reject this view, Plrysics 8.4 and Albert's commen
tary momentarily converge. But Albert closes Tractate Il, 3 with a remark
uniquely his own: even though the elements are one and continuous, their
form is distinct from their matter. 105 This difference, Albert goes on, is of a
different mode from the distinction between act and potency; therefore, it
does not imply that form acts as an intrinsic mover or that the elements can
be self-moving. 106 Here Albert anticipates a problem entirely absent from
Plrysics 8.4. Presumably, on Albert's view, the elements must have form and
form might serve as an intrinsic mover; so, like soul, it must be rejected. But
what is Albert's "different mode," and what is this "form distinct from
matter"?
Although Albert does not say so, the "different mode" of this form can
only refer to the theology of Tractate I and the fact that the elements must
be created. As first efficient cause, God gives things their first form ex nihilo.
This form constitutes the initial subject matter of the elements as created and
so should not be çonfused with the more usual sense of form, or soul, which
is the mover intrinsic to animais. Consequently, as created, the elements
must contain intrinsic form distinct from matter; but this form cannot be a
mover in the element. 107 Hence by both its theological origins and its status
143
Arisrode's Physics and lts Medifflzl Variecies
145
Aristode's Physics and lts Medieval Variecies
they differ in being and definition. Passive potency in a mobile thing grants
it an inchoate determination toward the form of the mover. 119 The moved,
whatever its present definition and being, is able to be acted upon by its
mover because its passive potency, as the inchoate form of the mover, relates
the moved to the form of the mover. Thus, in the moved, the inchoate form
of the agent orients a thing as mobile to this particular mover, so that it is
not generally the case that anything can move anything. On this analysis,
motion is the receipt of form from a mover to the extent allowed by the
inchoate form of that mover present in the moved; the explanation of mo•
tion by another lies in an account of how the mover as agent impresses de
veloped form onto the passive potency (the inchoate form of the mover) in
the moved.
The conceptual distance here from Aristotle to Albert can hardly be
exaggerated. While Aristotle aligns potency with matter aimed at form, Al
bert identifies potency with inchoate form of the mover present in the
moved. Correlatively, form's role in motion is also redefined. Aristotle re
quires one and only one form, which is a thing as actual. lndeed, for Aris•
totle, nature and art differ in this respect-art may be thought of as
possessing two forms, a natural form and an artistic form. But Albert always
requires two forms, that of the moved, which is the inchoate form of the
mover, and that of the mover, "impressing" second form onto inchoate form.
Albert gives two examples of passive potency, one from nature and one from
art: "The figure of a man is potential in the seed of a man and the figure of
an idol is potential in the copper by that way in which copper is the subject
of art."120 Where Aristotle distinguishes between nature and art, they are
the same for Albert.
Furthermore, in Albert's account, matter plays no active role in ex•
plaining motion, because the relation of the moved to its mover rests solely
on passive potency, which is not matter, but inchoate form that is
"susceptible."121 The inchoate form of the agent relates this particular mobile
to its mover by being prefurmed and thereby able to receive developed form
from the mover. This inchoate form resembles the nuiones seminalts of Au·
gustine (and ultimately Plotinus)-disorganized seminal reasons present in
matter that is preformed from the beginning-rather than Aristotle's matter
that "desires" form. 122
Albert requires passive potency, because he has redefined the problem
of elemental motion in a way that renders Aristotle's concepts useless. How
does essential motion occur, when the mover and moved differ in definition
and being? ln part, the answer lies in inchoata forma, or passive potency,
present in the moved. Mover and moved differ in being and definition, and
in this sense their being remains distinct; nevertheless, the inchoate form of
the mover present from the outset in the moved prepares or determines it to
receive second, or perfecting, form from its mover. Consequently, this first,
Albertus Magnus
147
Aristotle's Physics and Its Medieool Varieries
a mover, but the inchoate form of the agent in the moved determines how
much the heat will extend (i.e., how much the moved will heat up). The
"impetus" for the motion is a quantity of heat given by the mover; the in,
choate form for heat in the moved determines the extent to which the mo,
tion is effected; matter is neither the mover nor the moved; rather it serves
as the location in which the extension takes place. For Albert, these con,
cepts partially explain elemental motion as essential motion produced by
another.
The four elements are moved violently when they are moved outside of
nature; they are moved naturally when they are moved according to
nature.128 Fire and earth, Albert comments, have motion that is more man,
ifest than the motion of the middle elements (air and water), because their
passive potency is more absolute.129 Fire always goes up to the outermost
sphere of the heavens, (absolutely up), and earth always goes down to the
center of the cosmos (absolute down); the "middle elements," air and water,
always go to positions between these two extremes and are thus only rela,
tively "up" or "down."130 Albert amibutes the respective motions of earth
and fire (as well as air and water) to their passive potency, that is, to their
susceptibility for receiving form from their respective movers, and to the abil,
ity of that form to extend in the moved.
But the account is not complete. Albert now turns to Aristotle's ex,
ample of learning and knowing in the scientist. Here Aristode says that po,
tency may be spoken of in several ways, which accounts for the confusion
about elemental motion. Albert's explanation rests on the concept of passive
potency, which he distinguishes further.
According to Albert, passive potency is spoken of in two ways. ( 1) lt is
potency for knowing in an ignorant person who willingly learns. This po,
tency is prior because the ignorant person does not have potency in which
there is completion except as the inchoate form of the mover; but this in,
choate form constitutes no more than the most basic requirement for mobility
in the moved.131 This first potency is rightly called "per se potency" for know,
ing, inasmuch as it belongs to an individual as inchoate form that has not yet
been moved.
(2) Passive potency also indicates the one who, having been taught,
possesses science in habit but is not actually considering the objects of that
science at the moment. This person is able to perform knowledgeable actions
whenever his habit wills, unless he is impeded. Per se potency and habit can
be clearly distinguished: per se potency is receptivity for knowing, in which
"confused habit is not united"; habit, on the other hand, represents some
degree of knowing.132 Therefore, habit is not per se potency for knowing but
formed knowing, which may be impeded accidentally from the operation of
knowing. Thus if someone cries, "ls there a doctor in the bouse?" not the
person with per se potency but the one with habit may step forward.
Albertw Magnus
149
Arisrode's Physics and lts Mediewl Varieties
Teaching gives one science, that is, it moves one from ignorance to the habit
of knowing; in so doing, it also grants one "every thing that follows upon
science."
ln this argument, Albert uses yet another expression for passive po·
tency: "confused habit that is not united."m By giving science, teaching
unifies confused habit into the habit of knowing, and this habit includes
actual considering, because considering follows immediately upon the habit
of knowing. Therefore, Albert unequivocally identifies teaching as the
per se cause of both motions-potency to habit and habit to actually
considering. 116
The example of leaming and exercising knowledge is psychological,
but the analogy to elemental motion is clear. "Confused habit" is analogous
to inchoate form, while habit is the second form that can be received insofar
as "confused habit" is susceptible to it. Teaching is the generator that im•
poses science (second form) onto confused habit (inchoate form) and so
unîtes it insofar as it is susceptible. 137
But here a new point follows that has not yet appeared in Albert's ac·
count of the elements. W hen teaching has generated science in the leamer,
if nothing hinders, actually considering immediately follows. We shall see in
a moment how this point relates to the motion of the elements. But here we
may consider it in the example of leaming and lcnowing.
For Aristotle, because potency is aimed at actuality, potency is actual•
ized. ln the case of leaming, it is actualized first into habit and then into
actively considering. Thus, both moments are motions properly speaking,
and both require the identification of appropriate actuality as a mover. Fi·
nally, potency is actualized because it is identical in definition with actuality,
and after actualization it is actuality.
But for Albert, passive potency does not develop. Rather, the generator
impresses habit onto passive potency, confused habit that is not yet united.
This habit contains activity and, if nothing hinders, this activity immedi·
ately expresses itself. Since habit contains activity in itself, when it is im•
pressed onto the moved, activity too is impressed onto the moved, and so
whatever gives habit also gives activity. Consequently, where Aristotle needs
to identify actuality as a mover from habit to activity, for Albert, the gen•
erator that gives habit is the only requisite cause. Habit for Albert does not
need to be actu.alited; it needs only the opportunity for self•expression. Such
a notion of habit (or second form) resembles Neoplatonic form that, once im•
planted in matter, flourishes there and by expressing itself forms the thing. 138
Consequently, for Albert motion is the transference of form to passive
potency insofar as passive potency is able to receive it; the relation between
form and activity is a consequent expression (or extension) of second form.
The removal of a hindrance does not impart further form and so is not an
essential cause but only an accidentai cause, which by extrinsic action allows
Albertus Magnus
We now possess ail the pieces-from passive potency to form and to the
giver of fonn-for Albert's explanation of elemental motion. Like Aristotle,
Albert explains the motion of the heavy (also called "the cold") and the
light (also called "the hot"), that is, the elements earth and fire. The ac
count begins with potency and actuality: what is acrually cold is potentially
hot before heat is generated in it. Here Albert puts his concepts to work:
Heavy and light move the same way. First the heavy is potentially light, that
is, possesses susceptibility for the form of light. 141 When it becomes light, it
acquires from its generator both form and the activity that follows from it (if
nothing hinders). Wherever there is the form of light, operation immediately
follows (e.g., fire goes upward). If something impedes it, of course, the ele
ment is held down in a contrary place, as when air is in a closed vase or when
fire is contained in lignite: the activity contained in form is prevented from
expressing itself.
Albert now reaches the heart of the argument: the mover of the ele
ments is whatever gives form to them. lnsofar as the generator gives an ele
ment its fonn, "it [the generator] also bestows on it [the element] its place
and its motion [to that place]."142 As we have seen, Albert argues that during
violent motion the mover impresses a force onto the moved and the force
extends there insofar as the moved is susceptible to it. This account of nat
ural motion is identical to it: form dissolves in the moved, and activity im
mediately follows insofar as the receptivity of the moved allows. When fire,
possessing the form "light," cornes to be in earth, at the moment "heavy" but
possessing per se potency for "light," fire gives earth the form of being light.
Albert explains how this motion occurs. This form, "light," extends
within the passive potency of earth, and consequently "going up" follows im
mediately. The form "light" lifts the conjunction of fire and earth, insofar as
Arisrode's Physics and lts Mediewl Varieâes
the combination allows, that is, insofar as earth is susceptible to being lifted
by the form "light,'' the form of fire. This process-the form of the fire ex
tending and, consequently, lifting the earth-continues until ail the fire has
been ignited and, consequently, the combination has attained its natural
place. (Although Albert does not mention it, every combination would be
that distance from the outermost sphere that its essential combination of
light and heavy produce; in this sense, this account fits together with that of
Tractate I.)
Albert could hardly be more explicit in concluding his argument:
Here Albert answers the question "How does a mover, which differs from the
moved in both defmition and being, produce motion?" The "potentially hot"
contains passive potency or susceptibility for the form hot; when the gener
ator gives second form to passive potency, it gives everything entailed in that
form, including place and motion. Thus, for Albert, the cause of motion
must be the generator, the giver of form, and both motion and place follow
upon this form.
For Aristotle, the elements are moved by natural place, as any potency
is moved by its proper actuality. But for Albert, natural place and motion to
it are contained in second form and given by the generator that gives this
form. In short, while Aristotle's conception of motion rests upon the dy
namic orientation of potency to actuality, Albert consistently identifies po
tency with inchoate form. Aristotle's actuality and the dynamic orientation
of potency to actuality disappears, because in Albert's account, matter be
comes the location of form's expression, while the cause of motion is not ac
tuality but the generator, the giver of form. Second form immediately
contains both place and motion, and so no cause is needed beyond the gen
erator that impresses second form onto inchoate first form. In this sense, sec
ond form is complete: it contains within itself, and provides to the moved,
everything that is real, however temporary its appearance in the
individual.144 This notion of form-lilce Albert's concept of the generator
can only originate in Neoplatonism, whence Albert superimposes it onto the
argument of Plrysics 8.4 and the problem of elemental motion.145
Both Aristotle and Albert now complete their arguments by retuming
to the question of hindrances as accidentai causes of motion. Hindrances
function differently within their respective arguments. For Aristotle, potency
is always and necessarily actualized by its proper actuality. However, actuality
must be in contact with or continuous with the potential. Consequently, as
Alberncs Magnus
I argued above, the accidentai cause of motion from habit to actuality re·
moves an impediment so as to establish this necessary condition, contact or
continuity, between act and potency, with the result that potency is actual
ized by its proper actuality.
But for Albert, form that is given to the moved and that contains both
place and motion replaces actuality. Consequendy, Aristode's problem of
contact or continuity between mover and moved disappears; when an acci
dentai cause of motion removes an impediment, form, which has been given
to the element, may express the activity that by definition it already
contains. 146
An impediment "prohibits what is generated from performing the op·
eration of its form"-and the one who removes the impediment in a sense is,
and in a sense is not, a mover. 147 The generator is the essential cause of mo·
tion, because in giving form, the generator gives everything that follows as a
consequence of form. Whatever removes an impediment moves a generated
thing only accidentally, because it gives nothing essential to the moved;
rather, by removing an impediment, it frees a given form to express what it
essentially contains. 148
Aristode closes Physics 8.4 with a summary of the argument and its
conclusion, which in turn forms the first premise of his larger argument con•
ceming the overall construction of the cosmos: "Everything moved must be
moved by something." Albert, too, summarizes the argument; but here this
summary operates within an argument working from motion to its first cause.
Unlike Aristotle's, Albert's argument does not close by establishing a
premise; rather, the argument now leads to the next step in the progression to
a first mover-not Aristotle's first unmoved mover, but a Platonic self-mover:
"that everything that is moved is led back to some first mover that moves
itself."149
Albert closes the argument about the motion of the elements before
providing a more general summary. Clearly, he says, none of the simple bod
ies moves itself as Plato, Oalen, and Seneca thought. 150 Ail such things have
a principle of motion that, in giving form, gives motion and place to that
which they move.151 For example, when its generator gives fire the form of
light, it also gives fire natural upward motion.
Albert's more general summary completes the chapter by summarizing
his earlier arguments. Everything moved is moved either by nature or vio·
lently. Violent motion requires a mover that differs from the moved in being
and definition. In natural motion, some things, such as animais, are moved
by a mover distinct in definition but not being. Other things, such as the four
elements, are also moved naturally:
And likewise those things that are not moved by themselves and
are moved by nature, as heavy and light things; and they are
153
Arisrode's Physics and lts Mediewil Varieties
moved by some mover that is distinct from them per esse because
either they are moved by what generates them and makes [them],
by means of light and heavy, light and heavy in form, or [they are
moved] by what removes the impediment and prohibition, as
making the act of heavy and light. Therefore, everything that is
moved is moved by something distinct from itself through defi
nition and being or definition alone, and this is what we wish to
declare. 152
The chapter concludes with Albert's remark that the point here, namely,
"everything moved is moved by something," bas been proven not absolutely,
but only as determined by an inductive argument. 153 This remark, I shall
suggest in conclusion, brings us to the very limits of physics and its relation
to theology.
1
CoNCLUSION: ALBERT S CoMMENTARY AS
ARISTOTELIAN PHYSICS
This conclusion reveals both Albert's position and its distance from
Aristotle's-a distance defined first by the restructuring of Plrysics 8 into four
tractates, then by the theology of Tractate 1, and finally by Albert's use of
concepts originating in Neoplatonism. In redefining the structure of Plrysics
8, Albert bas also redefined the problems of Aristotle's physics and even
physics itself. He redefines the purpose of the arguments, the problem at
stake in elemental motion (and motion more generally), the solution to this
problem, and the project defined by these arguments. For Albert, the prob
lem of elemental motion concerns not the identification of a mover, but an
account of the way in which second form is given to inchoate form. He ar
ranges Aristotle's categories of motion into a hierarchy from the most exter
nat and accidentai mover/moved relation to the most internai and self
identical mover/moved relation. At the same time, the argument becomes
"inductive," moving from effect to cause, from the less knowable to the more
knowable. The problem of elemental motion is defined by its position within
this hierarchy.
The elements present Albert with the problem of how motion can oc
cur when mover and moved differ in definition and being. Within the ele
ments, Aristotle's potency, which is aimed at form, is replaced by Albert's
passive potency, which, as inchoate form of the mover, is susceptible to sec
ond form. As the cause of elemental motion, Aristotle's actuality, natural
place, is replaced by Albert's "giver of form," the generator of the elements.
The argument about the elements closes not with the proposition "Every-
154
thing moved is moved by something," but only with the first mover, which
serves as the object of the argument; because it is inductive, the argument
must reach the first cause of motion. Finally, place (e.g., up for fire), which,
for Aristotle, is the actuality of the elements and, hence, their mover (if
nothing intervenes), for Albert, is contained in second form, which is given
by the generator of the element.
Throughout his commentary, Albert's redefinition of the thesis, prob
lem, and arguments of Plrysics 8 is remarkably consistent. So for example, his
notion of the argument as inductive is consistent with the hierarchical ar•
rangement of motion, which in turn follows bis metaphysics of mover/moved
relations. We must now consider the coherence of bis position not only in
respect to the problem of motion, but as physics and theology joined together
within a single commentary on Plrysics 8.
We must first consider whether Albert's redefinition of the problem of
elemental motion occurs within the bounds of physics as Aristotle defines it,
or does it imply that physics, too, as a science, must be redefined? And if
physics is redefined-and I shall argue that it is-does this redefinition rest
solely on Albert's concepts within physics, or does it also involve the relation
between physics and theology?
After considering the unity of physics and theology in Albert's com•
mentary, we can conclude by assessing Albert's use of the commentary as an
intellectual genre. 1 suggested at the outset that the commentary leads a
"double life." lt functions first as a "reading" subordinated to a primary text,
the authority for the commentator without which there could be no com•
mentary. But it also functions as an original work. We have seen throughout
this section of his commentary, that Albert both follows Plrysics 8 and makes
it entirely bis own. W hat makes such a conjunction possible?
Albert's purpose in writing a commentary is to praise God; the purpose
of Plrysics 8, he says, is to inquire whether there is some perpetual motion
that is a cause of motion in general. The commentary on Plrysics 8 begins
with a digression that both explains the purpose of Plrysics 8 and explains how
God precedes the world. Thus, in Albert's reading of Plrysics 8, physics ap·
pears not as an independent science, but only in its relation to theology.
As we saw earlier, God's eternity is immutable, while the eternity of
the world is an unending succession of parts. God, acting as a first efficient
cause, makes the world out of nothing by producing inchoate form and or·
dering it to second form, which he also creates; natural causes produce their
effects by conjoining second form to first. As physicists, we cannot speak of
creation or the mode of creation directly-and so the discussion of God and
creation here in the commentary on Plrysics 8 is sharply restricted.
Physics, however, considers mobility in natural things. lnsofar as cre
ation is required for mobility, it appears within the science of physics. Be
cause mobile things are ordered by God to second form, and ail mobility in
155
Aristode's Physics and Irs Mediewd Varieâes
natural things rest upon this ordering, not only does theology appear within
physics, it is required by physics.
The theology ofTractate I explains the principles and possibility of mo•
bility in natural things, and so theology functions constructively vis-à-vis
physics. That is, theology provides physics not only with its objects, created
things, but also with the essential principles of motion that the physicist will
use to explain natural motion in things. Consequently, in Albert's commen•
tary, theology is neither tacked onto physics nor restrictive of physics; rather,
by providing its objects and principles, theology enables physics to function
successfully as a science. Thus, Tractate I establishes the objects and prin•
ciples presupposed by the account c:i motion in Tractate Il.
But what is the origin of Albert's conception of physics as a science
that requires theology to provide its principles and objects? Like so much of
the content <:i Albert's physics, it derives from Neoplatonism. We turn
briefly to Aristotle's account of physics as a science, and then we can con•
sider Albert's view.
In Plrysia 1, Aristotle argues that ail natural science must begin with
starting points that are not themselves proven (or, sometimes, even prov·
able). On the one band, if they could be proven, they would not be starting
points; on the other band, if the scientist were required to prove them, he
would never be able to proceed with the science itself.154 The unproven
starting point <:i physics is motion in things; thus in Plrysics 2.1, physics is
defined as the science that considers things that contain an intrinsic princi•
pie of motion, and Plrysics 8 begins not by asking whether there is motion,
but by asking whether motion in things is etemal. There is no account of the
origin of motion or mobility per se, although the account of the first motion
does include the cause required by it (Plrysia 8.10). Furthermore, since Ar·
istode defines motion as the actualization of the potential qua potential, the
radical subordination of potency to actuality established by this definition is
given as part of the "fact" of motion, the unproven starting point of physics.
Finally, given this definition and starting point, as I have argued above, he
cannot include an unmoved mover (called "god" in Me,a,,lrysia 12) within
the domain of physics.
Albert, of course, explains the origins <:i inchoate form and its re
lation to second form: God creates inchoate form out of nothing and orders
it to second form. By explaining the origin of motion in things, Albert im•
plicidy rejects Aristotle's daim that the fact of motion forms the radical
starting point for physics. His account of the origins of motion in things, as
I have argued above, derives immediately from Neoplatonism and ultimately
from Plato.
In a sense, Albert, Neoplatonists, and Aristode agree: the origins of
motion cannot be explained within nature or by a physics whose domain is
limited to nature in Aristode's sense. But they disagree about the limits and
Albertus Magnus
157
Arisrode's Physics and lts Medieval Varieiies
argument is not absolute, but only probable. While for Aristode motion in
things is etemal, for Albert the world exists only through creation and God's
free will. The world, and ail motion in it, is in no way necessary. Because the
relation between the world and God is not necessary, any argument from ef
fects to causes cannot be necessary. When in Albert's hands nature becomes
radically contingent upon God, arguments about nature can only be proba
ble. In this sense, the status of physics is redefined: as a science, physics
reaches only probable conclusions.
(2) Just as Albert redefines the science of physics, he also redefines na
ture in his account of elemental motion. Albert identifies the diverse causes
of elemental motion, that is, passive potency in the moved, the generator of
the element, and one who removes a hindrance. But if we ask, "what is the
generator of the elements?," Tractate Il, 4 does not tell us. A specific answer
to this question appears only in the earlier account of elemental motion, the
account in Tractate I, 13.
In this theological digression, Albert explains that the elements, like
ail created things, are created with inchoate form that must be perfected by
second form. The second form of any element is generated by its distance
from the outermost celestial sphere. Albert emphasizes the rich diversity of
nature, and his account reflects this emphasis: there are an almost unlimited
number of distances from the outermost sphere that serve as the generator,
the essential mover of the elements. Most importandy, this diversity origi
nates outside of nature in God, Who is a creator. Because for Albert nature
is created out of nothing through the free will of God, it is at once more con
tingent than Neoplatonic nature and known with less certainty than Aris
totle's nature. 155 Albert's account of elemental motion within physics could
hardly be bound up more closely with his commitment to creation by God
within theology.
Thus, from its tractate structure and conception of physics to the de
tails of the account of elemental motion, a single intellectual oudook dom
inates Albert's commentary. The historical origin of this outlook is largely
Neoplatonic, but Albert's physics is not just Neoplatonic. His conception of
the arguments as inductive and his view of the status Qf nature rest on his
view of creation and God as the efficient cause of nature. Finally, Albert puts
his concepts to work within a commentary on Aristotle's Plrysics.
Here we reach the final question that Albert's commentary poses for
us: what is the relation between Albert's Commentary and Aristode's Plrysics,
and how does Albert use the commentary as an intellectual genre? Aristode
may possess authority for Albert, but Albert remains the author of his com
mentary. The authority that Aristode possesses for Albert is an authority that
resides in bis treatment of problems crucial to physics. Through his commen
tary, with its corrections, or supplements, to Aristotle's physics, Albert can
explore problems in physics and, perhaps, acquire a share in that authority. 156
158
In discussing texts, medieval authors often introduce them in terms of
Aristatle's four causes: material, moving, final, and formai causes. 157 I shall
conclude by identifying the four causes of Albert's Commentary. The "mate·
rial cause" of the commentary is the shared technical terminology and com
mitment to the eternity of motion between Aristode and Neoplatonism.
Plata and Aristade share many philosophie terms, such as form and po
tency, but the meanings behind these terms differ dramatically. The case is
further complicated here by the history and usage of these terms in Neopla
tanism, which often elides (sometimes unintentionally, sometimes intention
ally) the conceptual differences between Plata and Aristode. lndeed, if we
think of the authority that Aristode and Plata as classical authors possess, we
can understand the commitment of subsequent philosophers to a use of tech
nical terms that could be referred to these authors, however much their
meanings were reinterpreted. Consequently, these technical terms provide
the "matter" from which the commentary is shaped. As a material cause in
this sense, the terminology and thesis that motion is eternal are one source
of "fluidity," that is, the ability to be reinterpreted, in Aristatle's Plrysics..
The "moving cause" of the commentary is Albert, its author. While
Aristotle's Plrysics orders and presents various problems--thus standing as a
primary text and authority-Albert expressly intends to correct and com•
plete whatever is wrong or incomplete in Aristotle's Plrysics. And we have
seen the effect of these corrections and completions. Thus, the commentator
bas not the absolute freedom of an author, but is also neither a mere scribe
who adds nothing to a text, nor a compiler who collects the opinions of
others: the commentator makes the commentary according to his own
intentions. 158
We must identify the "formai cause" of the commentary as the tractate
structure. The tractate structure provides the formai organization of the com
mentary; as I have argued, this organization superimposes a formai structure
onta Plrysics 8 that redefines physics, its problems, and the solutions of those
problems. The tractate structure isolates the problem of motion as eternal,
defines it, and determines its closure. Within Tractate l, the redivision of the
arguments into chapters and the introduction of digressions facilitates the in
tegration of theology and the subsequent redefinition of physics so as ta in
clude creation as the cause of mobility and order in natural things.
Similarly, Tractate II as a formai element in the commentary isolates
Plrysics 8.3-6 and restructures its arguments into a proof that allows Albert to
investigate the properties of motion "according to the consideration of a first
mover." Within the structure of Tractate li, Albert expands a few lines of
Aristade into a Neoplatonic causal structure and organizes the categories of
motion hierarchically. He thereby introduces new meanings into Aristode's
language and establishes Neoplatanic causes of motion, such as passive po·
tency and the generator of the elements. The problem itself of elemental
159
Aristode's Physics and lts Medieool Varieàes
r6o
Chapter 7
161
Aristode's Physics and lrs Medieool Varieâes
his own beliefs are suspended. 4 Rather, Thomas brings his own interests and
commitments to his commentaries while at the same time believing that he
and Aristode genuinely agree on many basic philosophie tenets. Conse
quently, his commentaries sometimes illuminate difficult passages and some
5
times radically rewrite Aristotle's postions. I shall argue that in his
commentary on the Plr,sics, Thomas changes the structure of Aristotle's ar
guments, with dramatic results for physics, both in its content and in its con
ception as a science. Consequently, in its logic, its content, and its
conception, Thomas's Aristotelian physics bears the mark of Thomas's own
originality. 6
I shall then turn to Jean Buridan and his Quaesâones on the Plr,sics. In
the fourteenth century, the flush of success for Aristotle's science passes into
a critical period. Buridan thinks of himself as the true interpreter of Aristo
tle; however, he writes not a commentary, or exposition, but "questions" on
the Plrysics. These questions develop individual propositions or theses from
Aristotle's Plrysics into what Buridan thinks of as a systematic Aristotelian
physics. But when Buridan takes a problem from the Plrysics, he develops his
solution to it in light ci the most recent scientific developments, often re
jecting Aristode's position as false. Thus, even though he works with prop
ositions from Aristotle's Plrysics, his own physics bears only a loose relation
to them. Consequently, considering the structure of Aristotle's Plr,sics and
its arguments alongside Thomas's "exposition" and Buridan's "questions"
can show us much of what is at stake between Aristode's Plrysics and Aris
totelian physics.
Each book of Aristotle's Plrysics opens with its main thesis. That is, Ar
istotle establishes the end, "that for the sake of which," firsr in each book.
Because the first moment of each treatise provides its formai thesis, subse
quent arguments are for the sake of this thesis and are subordinated to it. To
put the point negatively, the opening line is not a starting point from which
arguments set out, and Aristotle's arguments do not progress to a conclusion
with which they close. Rather, each book opens with its main thesis, and
subsequent arguments refer to and further support this opening thesis. By
looking at this structure, we can see how Aristotle's physics develops.
Plr,sics 2.1 opens with Aristotle's definition of nature; subsequent ar
guments do not move from this definition to a conclusion, but are solely for
the sake of explicating and establishing it. 7 ln this sense, the definition of
nature ser ves as the purpose or goal for the subsequent arguments. lndeed,
"nature" is the primary subject matter of physics as a science: nature is an
intrinsic capacity or potential to be moved or to be at rest.8
The Sb'UChcre et Plrysics
163
Arisrode's Physics and lts Medieval Varieties
thesis, motion in things, not the first mover, is the proper subject of the
argument. 17
As for Merat,lrysics 12, it opens with a thesis ail its own: "The investi·
gation concerns substance; for the principles and the causes being 50ught are
of substance".18 The investigation of substance ultimately includes God.
There is no failure in Plrysics 8. Aristode establishes the main thesis of the
argument (i.e., etemal motion in things) first, and the closing lines do not
lead forward to the god of Merat,lrysics 12, but refer back to the opening thesis,
etemal motion in things. ln fact, the- subject of physics is nature, that is, that
which contains an intrinsic ability to be moved; an unmowd mover by def
inition contains no such principle and 50 cannot be a formai part of the sub
ject matter of physics. Plrysics 8 cannot take god as a direct object of study
within its domain, because of Aristode's definition of nature and his notion
of physics as the science of things that are by nature. 19
Aristode's general conception of physics as a science appears when we
look across the books of the Plrysics. 20 Just as the arguments within each book
are not progressive or cumulative in their conclusions, 50 too, the books
themselves are not progressive or cumulative in their conclusions. ln fact,
just the opposite. Because the main thesis cornes first, subsequent arguments
are progressively more specialized and narrower within each book, 50 that
Aristotle's physics is sharply fucused on the requirements of motion and ul
timately on nature, the end for physics.
23
first cause of motion in the universe. This end in turn connects Plrysics
24
8 to the higher, more explicit treatment of God in MetalJ#rysics 12. As
Thomas structures these arguments, physics relates to metaphysics and ulti·
mately theology. 25
Since Thomas reverses the structure of Aristotle's arguments, we must
follow him and begin not at the beginning of the Plrysics, but at its end, Plrys
ics 8. The construal of its arguments as progressing toward an end is crucial
to physics in Plrysics 8. First, Thomas defines the primary problem to be ex
plained in this book: "ln hoc libro intendit inquirere qualis sit primus motor,
et primus motus et primum mobile. "26 This book, then, according to
Thomas, is not about the eternity of motion in things, the opening argu
ment, but the first mover, first motion, and first moved, namely, the clos
ing argument.
Assuming that the close of Plrysics 8 is its end, Thomas divides the
book into two parts. ln the first, he says, Aristotle establishes "quod est nec
essarium ad sequentem investigationem" (the [semp] eternity of motion),
and in the second part he proceeds "ad inquirendum conditionem primi mo
tus et primi motoris."27 This division closes the first argument, that motion
must be eternal, so that it may serve as a necessary condition for the second,
now more important, argument. According to Thomas, the argument for the
eternity of motion in things is complete at the end of Plrysics 8.2; Plrysics 8.3
sets out the main problem of the book, namely, how there is a first mover,
first motion, first mobile. A further subdivision allows Plrysics 8.3-6 to reach
general conclusions about the first motion and the first mover, while the
last argument of Plrysics 8 (8. 7-10) reaches the most specific conclusions
available within physics as a science about the first mover, whom Thomas
calls "God."28
Here we see how identifying the last argument of the treatise as its end
affects the substance and structure of the problems at stake within physics.
The opening thesis, that motion in things must be eternal, becomes a nec
essary condition for Thomas's main thesis, how there is a first mover, first
motion, first mobile. Aristotle's argument about motion becomes a proof of a
first mover, because Thomas transforms the solution of an objection into the
primary problem of Plrysics 8. He accomplishes this transformation by rede
fining the structure of the arguments. The end of the arguments, the purpose
for which they are developed, moves from the opening sentence to the con
cluding sentence, with the immediate result that the arguments are read as
progressing toward, rather than subordinated to, their end.
Within Thomas's structure, not only does the subject matter of the
argument shift from motion in things to the first mover called "God," but
the logical structure of the arguments is simultaneously rewritten. ln their
logical structure, Aristotle's arguments (and the problems of physics) become
narrower in domain because they address progressively more specialized
Aristode's Physics and les Medieval Varidies
objections to the first main thesis; the same arguments, for Thomas (and
hence his physics), become more specific (i.e., precise and important) in
their results, because they set out from an initial material condition in order
to progress toward the final conclusion of an argument; they progress from
effects to their first cause.
Given that for Thomas theae arguments progress toward their end,
what becomes of physics as a science? Stated briefly, according to Thomas
physics (and Aristotle's Plr,sics) progresses from principles of natural things
(Plr,sics 1) and principles of natural science (Plr,sics 2) through general con
siderations of mobile being (Plr,sics 3-6) to, finally, the first cause of the uni
verse, the first mover and his first effect, namely, the first motion (Plr,sics 7
and 8). Just as arguments of physics within each book are progressive, 50 for
Thomas physics as a science (and Aristotle's Plr,sics as a scientific treatise) is
progressive; it begins with the most general principles of nature and ends
with the highest knowledge available within the science of physics, knowl
edge of the unmoved mover called ''God."
Again this view exactly reverses that of Aristotle. For Aristotle, the
books of the Plr,sics do not progress toward an end; rather, the main thesis of
each book is first; later books refer to what precedes, because arguments be
come progressively narrower and more specialized. Physics is the science of
things that are by nature; Aristotle intends within physics to establish his def
inition of nature, to develop the concepts required by it, and to 50lve objec
tions that might be raiaed against it. But for Thomas, physics sets out from
the most general effect in order to arrive at its most important cause. Thus,
physics sets out from what Thomas calls "mobile being"-more about mobile
being in a moment-and culminates in the proof of an unmoved mover,
called "God."
What difference, if any, does sllifting the purpose of the argument from
its opening to its closing make to the way in which the problems constituting
physics are defined and 50lved? And what difference does it malte to the con
ception of physics? For Aristotle, physics is the science of things that are by
nature, namely, that contain within themselves a principle of motion, and
his arguments ultimately refer each subsequent problem or concept within
physics back to nature. Consequently, physics is neither progressive, accu
mulating conclusions or moving toward a highest cause, nor a series of quasi
independent topics, such as nature, motion, the infinite, place, void. Rather,
Aristotle subordinates each concept either mediately or immediately to his
definition of nature. Motion 's definition is for the sake of understanding na
ture; subsequent terms such as place or wid are developed for the sake of un
derstanding motion and, 50 ultimately, nature. Thus, for ail their diversity
and complexity, the problems of physics, for Aristotle, fall under one proper
subject matter, that from which it sets out: nature as a principle of motion
and rest.
166
The Stn1eture of Plrysics
BuRIDAN's QuAESTIONES
168
The Structure of Physics
Each question begins with the word whether and is answered completely
before proceeding to the next question. Furthermore, the questions not only
concem problems in physics but also openly ask if Aristotle's physics is cor
rect. For example, the first question on Plrysics 8 asks whether consideration
of a first mover properly belongs to physics as a science; and Buridan con
cludes that it is not legitimate to consider a first cause of motion within
physics.40 Buridan also asks whether Aristotle is correct in calling nature a
principle of being moved and being at rest, and again the answer is no, this
definition is wrong.41
These examples and the sequential structure of the questions bring us
to the first sharp difference between the Aristotelian physics of Thomas and
that of Buridan. For Thomas, Aristotle's Plrysics is the best possible physics,
even if 50metimes mistaken, and 50 Thomas's commentary is simultaneously
. Thomas's conception of Aristotle's physics and one of the best places to find
his own physics. But for Buridan, Aristotle's Plrysics is often wrong, 50 wrong
that Buridan rejects it outright. Consequently, the Quaestiones serve as the
locus for Buridan's physics, but that physics is often quite disengaged from the
. text of Aristotle that occasions it.42
For Buridan, physics is neither focused on nature in Aristotle's sense,
nor about mobile being in Thomas's sense; rather, science always deals with
individuals, that is, concrete subjects, according to universal rules.43 At its
most interesting, physics treats a complex set of problems concerning mo
tion. But Buridan conceives of motion not on Aristotle's definition (i.e., ac
tualization of the potential qua potential), but as a "moment-to-moment
velocity" within a whole.44 And it is this conception that informs first his
definition of the problems to be 50lved by physics and finally his view of
physics.
Buridan's best known contribution to fourteenth-century physics is his
concept of impetus, which is designed to explain projectile motion, both
what moves the projectile after it leaves the band of the thrower and how the
motion can be understood as a "moment-to-moment" progression. One of
the most important of Buridan's accounts of impetus occurs in his questions
on the Plrysics, Plrysics 8, Question 12. Since Buridan's questions on the Plrys
ics can be (and often are) read independently of one another, we can best
understand Buridan's physics, that is, both the subject matter of physics and
his conception of physics as a science, by turning directly to an individual
question. At the expense of backtracking to Aristotle's physics, the prob
lem at stalce in Plrysics 8 and Buridan's concept of impetus as a response to it
are revealing.
For Buridan's Quaestiones, the crucial text on projectile motion is Plrys
ics 8.10. Aristotle has shown that the first motion must be continuous cir
cular locomotion, and he now intends to identify the required cause of that
motion as a first mover that must be without parts and without magnitude.45
16g
Aristode's Physics and lrs Mediewl Varieties
CoNCLUSION
ln short, the same conclusions follow for Thomas and Buridan as did
for Philoponus and Albertus Magnus: the Plrysics is the Plrysics of Aristotle,
but the physics is the physics of the commentator. Thomas's exposition and
Buridan 's questions originate in the text of Aristotle's arguments or in his
definitions, but they are not restricted to these origins. Each commentator
restructures Aristotle's arguments to suit his own needs and in so doing, re
defines every element of Aristotle's physics.
Herein lies my first conclusion: the restructuring of Aristotle's argu
ments, whether into a progression leading to God or into individual ques
tions, does not leave Aristotle's arguments or his conception of physics as a
science untouched. Rather, the rearticulation of Aristotle's arguments into
logical and rhetorical structures wholly foreign to them at once enables the
commentator to make those arguments his own and reflects the changes that
have been wrought. And, as I have argued, these changes leave nothing un
touched: neither the structure of the arguments, nor the problems to be
solved that they present, nor the solutions to these problems, nor even the
general conception of physics within which this work takes place. Part of
what seems remarkable about these commentators, Albert as well as Thomas
and Buridan, lies in the fact that each uses Aristotle's Plrysics as the origin of
his own work, each produces a very different kind of commentary, and each
171
Arisrode's Physics and lts Mediewl Varieries
commentary presents a unity ail its own, a unity reaching from its structure
to its conception of physics as a science.
And in this unity lies my second conclusion: medieval varieties of Ar·
istotelian physics are not best thought ofas picking through Aristotle for the
true (and hence usable) bits while discarding the false (and hence unusable)
bits. Certainly, Albert and Thomas believe they are operating within Aris
totle's Plt,sics as a whole and, indeed, because they conceive of their work in
this way, they rearticulate the whole as a whole. With Buridan, the case is
prima facie less clear, because bis questions do allow him to affirm some prop·
ositions while denying others. But-and here is the crucial point-be is able
to conduct bis questions in this way because and only because he bas already
rejected the Plt,sics as a whole and as representing a structure larger than
propositions or very localized arguments. lndeed, for this very reason, the
Aristotelianism of Buridan and bis contemporaries often looks very remote
from that of Aristotle. 59
Medieval physics as conducted in the form of commentaries on Aris•
totle's Plt,sics represents a range of positions, striking in their variety and
originality. 60 And this point brings me to my third and final conclusion: the
restructuring ofAristotle's arguments, along with the rearticulation ofhis ar•
guments, does not originate in a sense that these arguments fail or are some
how inadequate and so in need ofimprovement. lndeed, quite the opposite.
Aristotle's arguments, at least in the thirteenth century, looked extremely
powerful-so powerful that everyone wants to be a part of them. Commen•
taries arise from the beliefthat the work ofthe primary source is worth pur·
suing, indeed that it will yield treasures.
The rearticulation of Aristotle's arguments originates not in a per•
ceived defect in his work, but in intellectual interests and commitments
wholly foreign to them. For Albert and Thomas these interests have two ob•
vious sources: Christian theology and Arabie commentators. Hence, and on
these grounds alone, can we identify the origins of the physics in each of
their commentaries.
While Albert and Thomas represent an "older" generation, Buridan
represents a "younger" generation. His interest in Aristotle's physics is me•
diated not only by theology and the Arabie commentators (at least to some
extent) but also by other developments in mathematics, physics, and even
the commentaries of Albert and Thomas. We can easily identify these in•
terests in bis rejection of a first mover as proper subject matter of physics as
a science and in bis account ofimpetus as the cause ofprojectile motion. For
Buridan, as for Albert and Thomas, the structure of Aristotle's Ph,sics, it
problems, arguments, and conception ofphysics as a science, are replaced by
others based on interests originating far from the physics of Aristotle.
Chapr.er 8
DuNs ScoTus:
Purr1No ANGELS IN THEIR PLACE
173
Arisrotle's Physics and hs Mediewl Variecies
effect. 4 For any two things to be together, they must in some sense occupy
place. Consequently, the answer to the question of whether angels in any
sense occupy place clearly must be yes. This yes-required by the finitude of
immaterial angels-raises within a theological context a complex problem
usually found exclusively in physics: the problem of place.
For Duns and numerous thinkers after him, the problem of how angels
occupy place involves both physics and theology, cause/effect relations as well
as the power and uniqueness of God. Aristotle's physics, that is, the science
of things containing an intrinsic principle of motion, cornes to be the science
of created beings, while theology constitutes the study of God. On the one
hand, as pure spirit, angels resemble God-indeed they are the closest to
God of ail created beings-and angels raise the problem of immaterial pres
ence; on the other hand, God's infinite power exceeds absolutely any power
possessed by angels, which, as created, are finite and so operate according to
the laws of ail finite creatures. The laws concerning how finite creatures op
erate as causes constitute the domain of physics. Consequently, the problem
of how angels occupy place as articulated by Duns raises important issues in
medieval physics-issues motivated by a theological requirement.
Indeed, the relation between physics, or science generally, and theol
ogy is at stake in the problem of how angels occupy place. The concept of
place-1 shall argue this point more fully later-is so central to physics, as
conceived by both Aristotle and Duns, that this concept cannot be shifted
without affecting the very nature of physics itself. Consequendy, in a precise
and rather limited problem, the concept of place required for the location
and operation of angels, we possess direct access to two much wider issues
critical to fourteenth-century physics and its relation to theology. By exam
ining the problem of how according to Duns angels occupy place, we can
grasp quite precisely at its origin what is at stake in the larger issue of the
subordination of physics to theology.
Within a theological context, then, Duns raises the problem of place
and so must define it. Citing Aristotle's Ph,sics, he defines it as the contain
ing boundary of the contained, that is, place is the immediate container of
the corporeal. 5 The peculiar inappropriateness of Aristotle's Ph,sics as an au
thority for a problem concerning angels appears as soon as we consider Ouns's
discussion of place in its theological context-a context, as I have argued,
not found in Aristotle's Ph,sics. 6 lndeed, a theological controversy originat
ing exclusively in Aristode's commentators, especially the Commentator,
Averroes, lies immediately behind Duns's discussion.
According to an Averroistic reading of Ph,sics 4, the relation between
place and body is so strong that it is necessary in itself, and not even God can
violate it. Consequently, God's power seems to be limited by this natural ne
cessity, and theology seems to be subordinated to physics. These views led to
the famous condemnation of Averroism in 1277 by the bishop of Paris,
174
Duns Scotus
!:tienne Tempier. 7 Tempier firmly asserted the power and freedom of God
over and above any natural necessity. If God so wishes, he can create a stone
that is not in place or move the world in such a way as to create a vacuum,
that is, place empty of body. 8 Herc we reach the heart of the difficulty: an
apparent contradiction between the authoritative physics of the time, Aris
totelian/Averroist physics, and what Tempier considered to be a necessary
truth of Catholic theology.
Duns's doctrine of angels as both wholly immaterial and finite involves
this difficulty. On the one hand, because angels are finite, they must occupy
place in order to be causally effkacious; consequendy, Duns requires physics.
On the other hand, the very physics to which he must turn seems to relate
place and its occupant so intimately that God's power becomes limited: the
physics required by Duns's angelology seems to entait heresy. The problem of
angels in place stands, we might say, at the very joint between physics and
theology, with the result that the solution to this problem must satisfy con•
ditions from both. Duns believes he can provide this solution.
Duns's treatment of angels dates from about 1305, and it is not surpris
ing to find him quoting Tempier. When the problem of place leads to theo
logically dangerous conclusions, Duns explicidy rejects Aristotelian/
Averroist physics in favor of Tempier and the 1277 Condemnation of
Averroism.9 Thus Aristode and Tempier are quoted on the same page. ln
citing these opposing authorities, Duns clearly believes he can in some way
resolve the incompatibility of Aristotelian physics and Christian theology.
Thus within the context of a problem concerning angels, Duns intends in
one and the same stroke to solve a problem in physics, the problem of place
and its occupants, to maintain a theologically orthodox position concerning
God and the distinction between God and angels, as well as to establish the
domains of theology and physics as compatible with one another. 10
This chapter will examine the argument of Duns Scotus with an eye to
understanding the problem of angels and place as theologically requiring an
excursion into physics and the actual occupancy of place by angels. In con
clusion, we can evaluate the distance from Aristode's Plrysics to the physics
of angels articulated by Duns, evaluate the position concerning angels in
place as Duns develops it, and indicate further historical reverberations of
this problem.
Physics, as Aristode defines it, considers all things that contain within
themselves a source of being moved and being at rest, and the most impor•
tant kind of motion is change of place, that is, locomotion. 11 And as I have
argued, place constitutes the world as determinate, all natural things must be
175
Arisrotle's Physics and lts Medieval Varieâes
in place, and place serves as the actuality of the elements out of which ail
things are composed.
When Christian theologians inherited this "place," it carried with it
implications wholly foreign to Aristotle. For Christian theologians, God
created the heavens and the earth ex nihilo. As created, the world depends
radically upon God for its very existence. Hence, no natural relation or
natural dependence of one creature upon another can either supersede the
absolute role of God as Creator or limit God's infinite power. But as Aristo
telian physics came to be interpreted, the relation between body and place
does exclude God and so constitutes a natural limit on God's power: body
must occupy place, and even God cannot create a body outside of place.
This conclusion provoked a series of condemnations culminating in that of
12 77. The problem of angels in place provides us with a case study in the
relation between physics and theology shortly after the crisis that produced
these condemnations.
Duns opens the discussion of whether angels are in place by distin
guishing God as infinite from angels as finite. 12 He has already argued that
God is immaterial and that angels, too, are immaterial; consequently, God
and angels at first glance look very much alike. Many Christian philoso
phers, Saint Bonaventure, for example, distinguish God from created finite
beings, including angels, by arguing that only God is purely immaterial and
ail created things, including angels, possess matter, as a principle of
limitation. 13 Duns rejects this position, arguing that angels as well as God are
immaterial. Consequently, he requires some other ground on which to dis
tinguish angels as finite from God as infinite. This ground lies in God's op
eration as infinite in contrast with the finite operation of angels, and as we
shall now see, it brings us face to face with the problem of place.
lnfinity, according to Duns, is the single most important and distin
guishing predicate of God. 14 But divine infinity is not to be understood in
terms of unlimited immateriality versus limited materiality; rather, God's in
finity must be understood in terms of God's operation, that is, his infinite
power and causal efficacy. God as infinite exercises absolute power and is free
of any restriction or qualification.
In Duns's technical language, God alone is "immense." "lmmensity"
indicates the absolutely infinite power and perfection of God taken in Him
self, prior to any extemal relation. ln this priority, immensity may be con
trasted with omnipresence. Omnipresence, too, is enjoyed by God alone and
expresses His infinity. But omnipresence represents God's infinity extemally,
that is, God as present throughout creation. Because immensity rests wholly
on God's intrinsic infinity, immensity stands independently of, and prior to,
any reference to anything outside of God. For our purposes here, the most
important conclusion following from the notion of God as immense is that,
as infinitely powerful prior to any extemal relation, God can act at any dis-
Duns Scotus
tance from His effect if He so wills. 15 Obviously, God is free from any nec•
essary relation to place. As Duns Scotus expresses it, the presence of God to
his effect is required less than that of angels to their effect. 16
Angels, although immaterial like God, do not share divine privileges
of power and causation. They suffer restrictions common to ail finite causes,
including the requirement that they be "together" with their effects. Being
"together" in turn requires that they occupy place. Because God and angels
are immaterial, this requirement alone separates God's infinite power from
the finite power possessed by angels. Thus it establishes and preserves the
uniqueness of God.
The problem of place, then, arises quite strictly because of a theolog•
ical requirement. However, Duns establishes the problem to be resolved,
whether angels occupy place, by first quoting and then interpreting Aristo•
tle's Plrysics. In the formulation of the problem, we can first measure the dis
tance from Aristotle's problem of place to Dun's problem of place.
As we have seen, in Plrysics 7.2, Aristotle argues that "everything
moved is moved by something" and that the mover and moved must be "to·
gether." Duns quotes Plrysics 7 and concludes that since angels are finite, they
must be together with their effects; hence angels too must occupy place. But,
according to Duns, angels involve no body or matter; they are immaterial.
When Duns quotes the Aristotelian dictum that movers must be together
with the moved, for "mover" we must understand "immaterial finite cause" in
contradistinction to "immaterial infinite cause." ln short, motivated by the
need to guarantee God's infinity, Duns replaces Aristotle's problem, "that ev
erything moved is moved by something,'' with the problem or how any finite
cause/effect relation takes place. Hence, the problem of place for things that
are by nature is recast as the problem of place for finite causes, which in the
present case, angels, are purely immaterial and contain no matter whatever.
Just as Duns recasts Aristotle's notion of "mover" from the dictum "the
mover must be together with the moved,'' he must also recast the notion of
"together." For Aristotle, "together" means in contact or touching, and
clearly expresses a material relation. Since Duns will discuss immaterial crea•
tures, he requires a concept that allows cause/effect relations to occur. So,
Duns interprets Aristotle to mean that causes and effects must enter into a
direct relation with one another, that is, the cause must be "present" to the
effect. But "presence"-a word ringing with Platonic overtones-signifies a
highly formai relation between cause and effect in which a material relation
is irrelevant. Duns requires such a concept precisely because his subject is
immaterial angels.
Hence, the problem that Duns sets himself in this discussion is to allow
immaterial angels sufficient occupancy of place so as to be present to their
effects. 17 At the very outset of the argument, then, the shift in the problem,
a shift from material relations to immaterial angels, simultaneously produces
177
Aristotle's Physics and lts Mediewl Varieàes
a shift away from the restricted problem of mover or moved things as neces
sarily "together," to the more formai problem of an, cause/effect relation re
quiring that the cause be "present" to the effect. The conception of place, I
shall argue, cannot but be recast in its turn, as it is developed by Duns to
resolve this problem.
Consequently, in this resolution of the problem of how angels occupy
place, we possess a case in which a theological problem, the necessity of dis
tinguishing between God and angels, leads into the domain of physics, the
problem of place. The relation between theology and physics is crucial here:
theology supplies the occasion and motivation for physics; physics supplies
the mechanism that fully distinguishes angels from God and thereby pre
serves God's uniqueness. But as I hope to show, physics cannot be shifted to
the theologically orthodox enterprise of Duns without effecting profound
changes in the nature of physics itself.
At the outset of his discussion, Duns agrees with Aristotle that "every
body, except the first, that is, the ultimate sphere of the heavens, is in place,"
and then quotes Aristotle's definition of place as the innermost motionless
containing boundary; furthermore, as Aristotle says, place is immobile and
indestructible. 18 But Duns immediately daims that the immobility and in
destructibility of place require a further distinction: place, in addition to be
ing immobile and incorruptible essentially (per se), is incorruptible
mathematically (secundum aequiw.zlentiam) but is not incorruptible acciden
tally (pet- accidens). 19
According to Duns, in addition to the immobility and incorruptibility
that place possesses per se, that is, by virtue of its definition as given by
Aristotle, place is "incorruptible according to equality through comparison
to local motion."20 The immediate sense of this technical expression is not
difficult. If a given body of fixed size moves from place A to place B, it has
indeed changed place in the sense of moving from one location to another
location; but the body has not changed place in the sense that the two lo
cations are dimensionally equal to one another. The two locations are of ex
actly the same size and shape and as such are interchangeable. 21 Hence,
place is "incorruptible" in the sense that a given fixed body must always oc
cupy the same dimension. Behind this apparently simple point stand impor
tant implications.
Duns grants place a dimensional incorruptibility that is independent of
change in location. Size, shape, and dimension are mathematical criteria ap
plicable anywhere precisely because size and shape do not change with loca
tion. Place as dimensional in this sense renders location irrelevant and, so,
178
Duns Scotus
1 79
Aristade's Physics and lrs Medieval Varieâes
,Bo
Duns Scotus
182
Duns Scoocs
place within the ultimate circuit of the stars? To put the question more gen·
erally, can physics "corrected" by Duns maintain its integrity as a science of
things that are by nature?
Duns explains that although, as we have clearly seen, there is no ne•
cessity that ail body be inside the closed circuit of the cosmos, there is noth•
ing intrinsically contradictory in such a view. 35 Ali body is able to be within
the cosmos, and it looks to us as if God willed that it be this way, even
though he could equally well have willed otherwise. For Aristode, ail body
must be in the cosmos, because of the relation between body and place; for
Duns, ail body hat>Pens to be in the cosmos, through God's free will. 36 This
is to say, body is not located within the cosmos because of its material na·
ture-such a view would in fact retum one to Aristotelian/Averroeist natural
necessity; rather, body always stands within the cosmos because of an ability
that attaches to body through God's free will and that is not itself material.
Duns calls the ability possessed by body to be in cosmic place without
contradiction "passive potency."37 Passive potency (its very name contrasts
with Aristotle's dynamic potency) is the primary principle that places body
into the cosmos. 38 Stricdy speaking, passive potency is nothing other than
ability to be in place without contradiction. Even though immaterial angels
(like body in this respect) need not be located in cosmic place, there is no
contradiction in their being so located; hence, they are said to possess passive
potency for location within the cosmos, and this potency is exercised at God's
will. Here lies the critical joint between physics and theology, the essential
moment in Duns's argument.
As a concept, passive potency operates simultaneously within physics
and theology. On the one hand, it preserves the integrity of physics as a sci
ence by serving as a principle of location for immaterial angels (and material
body) within the cosmos. As a principle of location, passive potency per•
forms the job for Duns's physics that natural necessity performs for Aristote·
lian/Averroist physics, while natural necessity has disappeared. But although
passive potency serves physics in this way, it nevertheless operates through
God's free will. Again, physics is made theologically orthodox.
On the other hand, theological implications follow from the way in
which passive potency originates in God's will. Although it serves to locate
body within the cosmos, as a principle passive potency is neither natural nor
material. Consequently, passive potency can serve to locate arr,thing, mate·
rial or immaterial, that God wills to be located. Indeed, as we shall now see,
angels possess passive potency for place in the strict sense that it involves no
contradiction to say that angels may be sent by God as his messengers and, on
those occasions, operating as finite causes, angels complete their tasks by ex•
ercising passive potency for place and so occupying it.
Here, at last, Duns answers his initial questions: yes, angels can occupy
place without entailing a contradiction. Because angels can occupy place,
183
Aristode's Physics and lu Mediewd Varieâes
they can be present to their effects and so operate efficaciously as finite be
ings, finite causes. As finite causes occupying place, purely immaterial angels
stand completely distinguished from God, whose uniqueness is hereby per
fectly preserved. At this moment in the argument, Duns's theological re
quirements have been met, and there can be no doubt d satisfying
theologians concerning the orthodoxy d this position.
But Duns must also satisfy the physicists. He quotes Aristotle but com
pletely revises an Aristotelian/Averroist conception of place. The notion d
passive potency that completes the location of angels in place is not to be
round in Aristotle's account of things that are by nature. Passive potency may
locate angels without breaking the law of noncontradiction, but it gives no
sense of what such location would entait, or how it would occur. The physics
d locating immaterial angels remains for Duns to complete.
18.f
(4) Body and place are commensurate, such that the parts of the body
correspond to the parts of the container, and the entire body corresponds to
the entire container. 42 Obviously angels do not occupy place in this sense,
since they have no matter and, consequently, no parts. 43
(S) Each body has a determinate place that lodges it. 44 Duns's single
sentence here does not articulate the point fully. He may mean that ail body
is in place in a determinate way by virtue of the particular place that contains
it. Of angels, Duns explains that they are in "this or that place" only because
they are not ubiquitous. 45 That is, bodies are contained by place in a deter
minate way, while angels are determined to place only in a general way by the
denial of ubiquity. 46
(6) Body and place are determined to each other in virtue of the sub
stantial furm and determined qualities of the body. 47 Here Duns returns to
something like natural place in Aristotle. One place conserves the substan
tial form and determined qualities of a body better than another place, which
might corrupt them. Angels are never in place in this way, because as im
material they never relate to place in such a way as to be better conserved or
more corrupted by one place than another. 48
We can now return to point (3), the critical characteristic of the place/
occupant relation: the equality of the occupant to its place. We say that a
containing place is equal to its contained occupant. 49 ln fact, Duns tells us,
this determinateness is just the characteristic that allows two places to be di
50
mensionally interchangeable, as Euclid himself shows. The crux of the
problem rests on just how an angel as pure spirit possesses the determinate
ness to be in a particular place. Again, the problem of distinguishing be
tween angels and God lurks in the background.
The problem is this: an angel bas no configuration, because it bas no
quantitative dimension. 51 Consequently, it might appear that an angel could
occupy any place however small, even a point, or any place however large,
even a quadrangle whose sides are extended to infinity. 52 But as we have al
ready seen above, the possibility of occupying an infinite space, that is, of
being ubiquitous, can belong only to God, and if God's uniqueness is to be
preserved, this possibility must be denied to angels.
The problem fur Duns here at the level of characterizing the placebc
cupant relation is no different from that solved at a more abstract level by
passive potency: angels must occupy a determinate place in order to preserve
the distinct uniqueness of God. The theological motive, which passive po
tency addresses earlier, reappears at the crucial moment within the physics d
the placebccupant relation.
Angels, we might say, occupy a determinate place in an indeterminate
way. That is, occupancy is neither natural to an angel in the sense that it is
natural to a body, nor is it repugnant to its nature. lts nature is neutral to
place and so can be contained in a determinate place, however large or
185
Aristode's Physics and lts Medieml Varieries
CoNCLUSION
186
the theological goal of orthodoxy by preserving God's uniqueness as infinite
and omnipotent. There also can be no doubt that its physics remains prob
lematic, and it is to this final point that we can now turn.
(3) One may say fairly that Duns's solution to the problem of how im
material angels occupy place-they are determined to occupy place indeter
minately-remains problematic. William of Oclcham, for example, is
unrelenting in his criticism of Duns on this point. 55 With the rise of New
tonian science, the question of angels in place cornes to stand for ail that is
ridiculous in medieval theology and science. 56
I would like, however, in closing to suggest that the problems consid
ered by Duns in the context of God and angels remain as problems in post
Newtonian science and philosophy-indeed, they are with us today. Angels,
according to Duns, must be present to their effects, but God can act at any
distance. In modern terms these problems become pure mind present in body
on a Cartesian model and the problem of force, or gravity, which is some
times called "action at a distance" in Newtonian physics.
In Newtonian terms, the problem of action at a distance becomes the
problem of gravity. With gravity, Newton was regularly accused of introduc
ing "occult qualities" into science. Gravity as a force in Newtonian physics
possesses important characteristics of God in post-1277 theology, and so
Newton is often accused of positing a "hidden God." Newton defends bis po
sition in a number of ways, which shows how seriously he felt this criticism. 57
Like Duns, neither Newton nor anyone within the Newtonian framework has
ever satisfactorily answered this problem. Rather, "gravity," looked at histor
ically, cornes to have the status of an observed fact rather than an explana
tory principle. 58
The problem of mind present in body also has a long career. Mind as
immaterial in Descartes strongly resembles angels as immaterial in Thomas
Aquinas and Duns Scotus. The problem of locating mind in a body for Des
cartes and his followers perfectly parallels Duns's problem of putting angels in
place. Descartes, too, seems to admit the impossibility of explaining how
mind is present in body. 59 He merely says that we may observe that it is so
present. No solution has yet been found: post-Cartesian philosophy either
redefines soul and body, declares a solution to be impossible, or struggles yet
with the original problem.
We noted throughout this examination of Duns that bis motives are in
a primary sense theological. These motives are part of the intellectual her
itage of the Condemnation of 1277, namely, the protection of God's omnip
otence and infinity. We may conclude that he is successful theologically but
only at the price of an enormous ambiguity for science and philosophy as dis
tinct from theology. That ambiguity, which remains unresolved, may at one
and the same moment mark the terminus of Aristotelian physics and stand as
the most important heritage of the problem of angels in place.
Notes
lnLTOducâon
1. For a good review of the translation of Aristotle into Latin, see Ber
nard G. Dod, "Aristoteles Latinus." On the assimilation and interpretation
of the Plrysics within European universities, see James A. Weisheipl, "The
lnterpretation of Aristotle's Plrysics and the Science of Motion," and John E.
Murdoch "lnfinity and Continuity," where Murdoch comments (565) that
"the Plrysics was the most commented upon of Aristotle's natural philosoph
ical works through the first half of the fourteenth century." Edward Grant
argues "that the Aristotelian system continued to hold the allegiance of the
overwhelming majority of the educated classes in the seventeenth century, its
final century as a credible system" in ln Defense of the Earrh's Centralir, and
lmmobilir,. 3; he considers the overall problem of the "longevity" of Aristo·
telianism in "Aristotelianism and the Longevity of the Medieval World
View."
13. For evidence that Aristotle's writings were called progmateiai in an•
cient times, see John P. Lynch Aristotle's School: A Study of a Greek Educa
tional Institution, 89, and 1. Oüring, "Notes on the History of the
Transmission of Aristode's Writings," 37-70.
15. Ibid.
16. For evidence that both the Academy and the Lyceum were orga·
nized as communities of equals that encouraged diversity of thought rather
than established a codified position, see Lynch, Aristotle's Schoo� 75-86.
This view is further supported by Ilsetraut Hadot, who extends it historically
to include the Neoplatonic Academy as well. Hadot, Le Problème du Néop'fa.
tonisme Alexandrin Hierocles et Simplicius, 9-14.
18. Ibid.
22. lt has been suggested that "scholarship" is one of the great inven•
tians of the Hellenistic age, beginning with the earliest Peripatetics and Neo
platonists. See Rudolf Pfeiffer, History of Classical Scholarship: From the
Beginnings to the End of the Hellenistic Age, 152. A.-H. Chroust makes the
important point that after Aristotle's death, "the commentary in a way took
the place of Aristotle the teacher," in "The Miraculous Oisappearance and
Recovery of the Corpus Aristotelicum"; cf. 55.
24. Examples abound in Jaeger. For one, see 30lff., where parts of the
De Caelo are related to parts of Aristotle's "lost dialogues," On Philosophy.
Solmsen finds a sentence added in Plr:,sics 8.6 that changes the original in•
tent of the book. Solmsen, Aristode's S:ystem of the Plr:,sical World, 240 n. 60.
26. Again, see M. Grene: "But to draw the sort of conclusions Jaeger
draws we have to suppose that Aristotle simply incorporated into his lectures
a hodgepodge of inconsistent bits from earlier days. And this for two reasons
seems to me an unreasonable thing to do. For one thing, the most obvious
characteristic of Aristotle, on the face of his writings is neatness. . . . The
Aristotelian corpus must have, in its main outline, something like the order
it says it has. Secondly, even if scholars can ferret out earlier lines of orga·
nization, the corpus as we have it does, as I have just said, represent, in most
subjects at least, the lecture course at the Lyceum as Aristotle conceived it
after the definitive period of biological research. And so we are entitled to
study it as such, whatever its genesis." Grene, Portrait of Aristode, 33.
27. As Grene so well says: "The whole procedure finally issues in a sort
of Heraclitean flux: from one page to the next one is never reading the same
192
Not.es ro Introduction
Aristotle, and finally there is no Aristotle left to be read at ail." Grene, Por
&rait of Aristode, 27-28.
32. For a study of the term Etôoç as originating in Plato but reinter
preted by Aristotle, see D. W. Hamlyn, "Aristotle on Form."
193
Arisrode's Physics and lu Mediewd Variecies
38. Aristotle, Plr,sics 3.1-3 concerns motion and 3.4-8 concerns the
infinite. Plr,sics 4 first asks what is "the where" of things that are by nature
and affirms place (1-5) and then rejects void (6-9) as "the where"; an anal
ysis of time follows (10-14). Plr,sics 6 takes up "the continuous" and special
problems entailed by it.
40. On the logoi and Aristotle's writing more generally, see J. Owens,
The Doctrine cf Seing, 75-83.
43. Ibid.
45. Although the problem lies beyond the bounds of this study, I might
mention here the relation between the Posrerior Analytics and Aristotle's "sci
entific research" suggested by J. Barnes in "Aristotle's Theory of Demonstra
tion," in Articles on Aristode, vol. 1. Barnes suggests that "the theory of
demonstrative science was never meant to guide or formalize scientific re
search: it is concerned exclusively with the teaching of facts already won; it
does not describe how scientists do, or ought to acquire knowledge: it offers
a formai model of how teachers should present and impart lcnowledge" (77;
Barnes's italics). And Posrerior Analytics 1 supports this daim by announcing
Nota r.o Introducrion
its topic in its opening line: "Ali teaching and ail intellectual leaming corne
about from already existing knowledge" (Barnes's translation). This thesis is
developed by Bames more fully in "Proof and the Syllogism." lt is criticized
by William Wians on the grounds of its presupposed disjunction between
teaching and research as well as an anachronistic view of teaching. Wians,
"Aristotle, Demonstration, and Teaching."
46. We may note here the implicit problems with editions of Aristotle
that "eut and paste" parts of individual books. See A New Aristode Reader,
ed. J. L. Ackrill. From Plrysics 8, Ackrill gives only chapters 6 and 10!
47. For a good sense of the range of meanings given the term Aristo
telian, see Edward Grant, "Ways to lnterpret the Terms 'Aristotelian' and
'Aristotelianism' in Medieval and Renaissance Natural Philosophy."
48. l should note here that in part 2 l do not note issues in Aristotle
that have been argued and noted in part 1.
49. For an exception, cf. Anthony Kenny and Jan Pinborg, "Medieval
Philosophical Literature." However, no consideration is given to the relation
between forms of writing and meaning.
56. This issue has received much attention in the literature. See, for
example, I. Düring, "Notes," 37-70; J. J. Keaney, "Two Notes on the Tra
dition of Aristotle's Writings."
19 5
Arisrode's Physics and lts Medieval Varieâes
57. Again, this issue lies beyond the scope of the present study. For
example, see Hadot, Le PTOblème, passim; H. J. Blumenthal, "John Philopo
nus: Alexandrian Platonist?"; Pfeiffer, History of Classical Scholarship,
152-209.
61. Not ail its members were Christian. Ammonius, for example, was
not. And Christian dogma was not a formai part of the school. Nevertheless,
the political arrangements with Christianity must have had an impact on the
intellectual life of the school.
196
Notes ro Chat,t.er l
197
Aristode's Physics and lts Mediewl Varielies
24. Charlton notes that Aristotle uses the word horme, which means
active striving, and argues that it should be associated with matter. Charl
ton, Arisrode's Plrysics, 92.
199
Aristode's Physics and lts Mediewl Varieâes
plishes the generation by contact with the material that has the appropriate
passive potentiality" (Gill, ATistode on Substance, 195). We may note here
that Gill confuses art, which requires imposition of form on passive matter,
with nature, which requires only contact between matter and form precisely
because no imposition is needed-in nature things go together "naturally,"
because matter is not passive but oriented toward form. L. A. Kosman con
siders different meanings of d:ynamis and ene,-geia and emphasizes the active
sense of d:ynamis, in Kosman, "Substance, Being, and Energeia, '' 121-49; see
esp. 121 n.l.
29. Aristotle, Plrysics 2.1.193b5-6: "to 6' ÈK tO'Utù>V C,,ua,c; µÈv oilK
Ëotl.V, C,,uœ, 6É, otov liv8pom:oc;."
38. For an account of how the Neoplatonists later fight back, see Rich-
ard Sorabji, Matr.er, Space, and Motion, 250ff.
41. Ibid.
200
Not.es ro Clia,,,.er J
43. Plato, Phaedrus 245d�7: "oirtw 6T) ICt.v,\OEœc; µÈV àPXT) 'tO airto
airto ICt.VOÛV." Cf. l.aws 10.896a4.
44, Plato, Phaedrus 245e5-246: "mv yàp a<Îlµa, l.p µÈV Ësœ8EV 'tO
ICt.VEÛJOat., &,t,uxov, l.p 6È Ëv008EV Œi1:«l) ÈS ŒvtOÛ, ˵,t,'lJXOV, 6>c; 'tŒ'U'tTlli
oflffl)c; ct,i,œwc; ,iroxiic;· d 6' ËO'tLV 'tOÛ'tO 0\J't(l)c; ËXOV, "" &llo 'tL Elvat.
'tO airto ÉŒU'tO ICt.VOÛV i\ "i'UX'l", Ès àvâ'YICTlc; àyÉV'l't6v 'tE ICQL
à8âva'tov ,t,uxT) liv ELT)."
48. Note the sharp contrast here between Plato's phrase at Phaedncs
245e5, 'f\>
µÈv fsw&v 'tO 1Ct.VELCJ8at.," and Aristotle's definition of nature as
some source and cause, "'tOÛ 1Ct.VELCJ8a1. acat ilPEflELV ÈV l.p ÜJtÛPXEL
,w;pdnwc; ••• ," at Plrysics 2.1.192b21-22.
So it is clear in ail these cases that the thing does not move itself,
but it contains within itself the source of motion-not of moving
something or of causing motion, but of suffering it. (255b29-31)
fi
52. Aristotle, Plrysics 2.1.193a9-11: 11001CEL 6' cpumc; ICQL oi1aw fi
'tÔ>v cpuœt. lmwv lvw� Elva1. 'to xpônov lvuxâPXov Éacâcnp,
àppu9'1LC1tov (6v) aca8' ÉŒU't6, otov nLVT)c; q>UOLc; 'tO s"UÂ.ov,
àv6p1.âvtoc; 6' ô xcwc:6c;."
201
Aristode's Physics and lu Medieval Varieries
60. For a different construal of the analogy between art and nature
here, see Jonathan Lear, Aristode: The Desire ro Undmrand, 16-18.
61. On this shift in meaning, see David Furley, The Greek Cosmologisis,
1:178.
202
Notes to Chapr.er 1
65. See Homer, Od,ssey 23.175-204, for the crucial passage discussed
here.
66. A. Amory, "The Gates of Horn and Ivory," 45, 54-55, discusses
the symbolism of art and ivory in the bed image of Homer but fails to men•
tion either Aristotle or the importance of the olive tree.
70. lt may be objected that Homer and Aristotle use entirely different
words for bed, Mxoi; and ICÂ.Cvri, respectively. But Homer's word is poetic
and never appears in prose, while Aristotle uses the standard prose term of
his own time. lt would be entirely archaic and unnatural for Aristotle (or
Antiphon) to use a poetic term from Homer. lndeed, the natural presence of
an ancient poetic sign interpreted into the contemporary philosophidscien·
tiflc idiom attests to the vitality of that Homeric sign throughout the long
development of Greek culture. And it enters that sign into an immediate re•
lation with Aristotle's own view of "things that are by art" and the relation
of artifacts to his own primary interest, "things that are by nature."
203
Arisrode's Physics and lu Mediewl Varieries
75. Stanford, referring to van Leeuwan, notes that at line 178 the use
of the imperfect, the bed Odysseus himself made, is from the sixth century
used to indicate an artist's signature. Stanford, Odyssey of HomeT, 398.
76. See Stanford, Odyssey of HomeT, 399. He comments on lines 190ff
that nobody has satisfactorily explained the curiosity of the bed.
205
Arisrode's Physics and lis Medieval Varieties
20. This point is made, although not argued, in the notes (276) to a
recent translation of Physics 7: Aristodes' Physik: Vorlesung über Natur; Zweiter
Halbband: Büch V (E)-Vlll ( 9), trans. with intro. and notes by Hans Günter
Zekl (Hamburg: Felix Meiner Verlag, 1988).
22. lndeed, although the point is not expressed this way, for Aristotle
an identity of mover and moved would break the law of noncontradiction-a
thing would be both mover and nonmover in the same respect at the same
time.
23. Plato, Phaedrw 245e; Laws 10.895. Ail references to Plato are to
the OCT. Plato's arguments conceming soul as the immortal source of mo
tion to ail elsc have becn a source of controversy. For a review of textual dif
ficulties in the argument of the Phaedrus, see T. M. Robinson, Plato's
Psycholoe, 111-18; on Plato's theory and its relation to Aristotle's criticisms
of Plato, see H. Chemiss, Aristode's Criticism of Plato and the Academ:y, 423ff.
Chemiss argues that the theory of soul as the principle of ail motion appears
not only in the Phaedrus 80a, 94b-c, and Laws 10, but throughout Plato. Cf.
Gorgias 465c-d; Phaedo 80a, 94b-c; and Republic 1.353d. This view is crit
icized by Robinson, Plato's Psycholog,. 115 n. 13. Also see R. Demos, "Plato's
Doctrine of the Psy che as a Self-moving Motion," 133-34.
27. Plato, Phaedrus 245e; Laws 10.895; Timaeus 34a. See Chemiss, Ar
isrotle's Criticism, 455. AU translations are my own except where otherwise
noted.
ail motion in the cosmos. Aristotle, in his usual sense of motion, that is,
"the fulfillment of what is potentially insofar as it is potentially" (Pla,sics
3.1.20lal0-ll), does not call thinking a motion, and in three separate ar
guments traces all motion to a first mover. (On this problem in Aristotle,
see Enrico Berti, "The Intellection of Indivisibles According to Aristotle, De
Anima 3.10," 153. Thus, we find that Proclus includes a refutation of the
proposition that everything that is moved is moved by another, within a
general refutation of materialism, while Thomas assures us that Plato and
Aristotle are not really in disagreement, since Plato's doctrine involves only
the spiritual, and Aristotle deals with motion as material. See Proclus, The
Elements of Theolog:,: A Rewed Text with Translation and Commentary, prop.
17-21; Thomas, ln Ph,s. VIII, lect. 1, par. 890.
30. The history of problems concerning the relation between God and
soul for Aristotle is immensely interesting. See for example Owens, "Aquinas
and the Proof from the 'Physics'," 123; M. de Corte, "La Causalité du premier
moteur dans la philosophie aristotélicienne"; J. Paulus, "La Theorie du pre
mier moteur chez Aristote," 283; A. C. Pegis, "St. Thomas and the Coher
ence of the Aristotelian Theology." This anti-Platonic moment of Physics
7.1, i.e., the argument against self-movers as self-identical, is repeated at
Physics 8.5.
34. Ibid.
207
Aristode's Physics and les Medieval Varieàes
39. Cherniss also takes this position, in Aristode's Criricism of Plata, 412
(cf. note 21).
42. Aristotle, Plrysics 7. l.242a6; see Pegis, "St. Thomas and the Co
herence," 87.
2o8
Nor.es ro Chapt.a 2
51. Ross, Aristode's Ph,sics, 669-70. Ross daims that "the argument
turns on the general consideration that events that are simultaneous with the
same event are simultaneous with each other." But this is clearly false, since
the point that Aristotle is making follows froD) the relation of the moved
movers in the infinite series. There is no mention whatever of any first or
"same" event from which the simultaneity of the others can follow. In fact,
in an infinite series in which ail the members are of equal status, there can
not be any "same" event to which ail others can be compared. For if there
were, it would serve as a standard for the others and hence would not be of
equal status with the others.
209
Arisrode's Physics and les Medieva! Varieries
what is telling fur the argument of Plrysics 7 is the absence of thcse terms or
any conclusions about motion that requin! their introduction hen!.
57. Ross, Arisrode's Plrysics, 670. Although Ross raises this objection
later, that is when! Aristotle introduces contact between the moved movers,
it bears upon this moment in the argument.
63. Aristode, Plrysics 7. l.242b50-53: "Èltd 6' 6"« ICLVEL'tŒL JCai. 'tO
A JCai. 't<Î>v &llorv ËJCaatov, 'fi ÔÀT) dvqaLc; ÈV 'ât>
a'6'â\> Xf)ÔV<e lata1o
ICŒL 'fi 'tOÛ A· 'fi ÔÈ 'tOÛ A ÈV 2WŒpaq.LÉV'\). ù>OtE d11 &v WIELpoc; ÈV
JWtEpaq.LÉV'\), 'tOÛ'to ô' àôwmov." The Oxiord translation n!nders Aris-
210
Nota ro Chapt.er 2
totle's "&" as "and ." But the particle is better undentood as somewhat ad
venative, and it indicates a slight break in the argument . lt is bettcr
translated by Apostle "Now since...." Apostle,Aristode's Physia, 130.
211
Arisrode's Physics and les Medieval Varieties
77. Verbeke suggests that the crucial point of the objection is that the
moved movers must move simultaneously; Verbeke, "L'Argument," 253.
While it is true that they must move simultaneously, the simultaneity the ex
motion is not raised here and is not the primary fucus of the argument.
79. The same point can be made in another way. "Ali the parts retain
their respective positions to one another." L. Eiders, Arisrode's Titeor, of the
One: A Commentary on Book X of the Meraplr,sics, 60.
80. See Apostle, Arisrode's Plrysics, 301, n. 20.
90. So, for example, Verbeke daims that Aristotle must abandon the
reasoning of Plrysics 7 for the arguments of Plrysics 8 and Meraplrysics 12. Ver•
beke, "L'Argument," 267.
212
Noœs to Chaprer 2
91. Paulus, "La Théorie," 299; Owens, "Aquinas and the Proof," 123.
Cf. the review of these problems in Pegis, "St. Thomas and the Coherence,"
78, 116-17. On the strength of this daim, Paulus and Owens identify the
mover of Plt,sics 7 as a first moving cause, perhaps the soul of the outer
most heaven, and deny that this mover can be a first final cause, the God
of Mera,,lrysics 12. Pegis effectively (and for me persuasively) criticizes this
interpretation.
92. These arguments are identified by both von Arnim and Verbeke,
who fail to make this distinction. Cf. H. von Arnim, "Die Entwicklung der
Gotteslehre," 24, and O. Verbeke, "L'Argument," 250.
213
Arislode's Physics and les Mediewl Varieâes
matter. Also, F. de Gandt "Force et science des machines." The same argu•
ments are comidered (much more persuasively) by H. Carteron, "Does Ar·
istotle Have a Mechanics." Carteron rejects the view that "inertia" is a
meaningful criterion applied to Ariatotle's theory of motion, because it is en•
tirely fureign to that theory, and rejects the view that Aristotle has a me•
chanics of motion at ail; finally he points out that "we should not give a
systematic arrangement to formulae collected from different works" (171).
(He does not, however, understand the structure and purpose of Aristotle's
arguments as I do. Rather than seeing various Joaoi
as solving sharply defined
problems, he interprets them as "establishing, or paving the way fur the es
tablishment of physical or metaphysics properties" (171-72). Such a view ia
but another form of abstraction.) The incompatibility of Aristotle's teleology
with a mechanics of motion is also argued by Jonathan Lear, Aristode, 36.
21.,f
Notes to Chapter 3
215
Aristode's Physics and lu Medimzl Variecies
de's De Moeu Animalium 118ff. lt ia true, as we shall see below that animal
motion is discussed in Plrysics 8.4, but this discussion concems animais as
exhibiting motion, so that the rule "everything moved is moved by some
thing" must apply. That is, animais too may be considered a part of the struc
ture of the cosmos. For an able criticism of Nussbaum's arguments about the
relation of physics and biology as a science, see J. Kung, "Aristotle's De Motu
Animalium and the Separability of the Sciences."
11. Plrysics 7 is ofœn grouped with these, but we have considered this
argument in chapter 2.
14. For examples of some of the problema that result from this conjunc
tion, which is attributed directly to Aristotle, see J. Maritain, Bergsonian Phi
losof11ry and Thomism, 357-60. a. A. C. Pegis, "St. Thomas and the
Coherence." For an example of an analysis of Aristotle's "prime mover," a
term that moves through not only these texts but several others, without re
gard to the purpose or use of the arguments, see Charles H. Kahn, "The
Place of the Prime Mover in Aristotle's Teleology."
216
Notes to Chat,œr 3
28. Aristotle repeats the question that opened Plrysia 8.3 at Plrysia
8.6.260a12-13.
217
Aristode's Physics and lts Mediaoal Varieries
42. Cf. Aristotle, De Caelo I.2.269a7-19, for the definition and ex
amples of the four elements. Also l.8.276a23ff.; 3.2.300a23-27; On Gen
eraâon and Corruption 3.6.333b26-30.
218
Notes ro Chapt.er 3
46. Herbert Davidson puts the problem well: " 'Nature',a well-known
Aristotelian formula affirms, is 'a certain principle and cause of [a thing's]
being moved and being at rest' [Plrysics 2.1.192b2 1-22] ....Yet side by side
with the characterization of the motion of the elements as natural,Aristotle
had undertaken to establish that the sublunar elements 'are not moved by
themselves' [Plrysics 8.4.255alff]. That is to say, although the elements are
moved owing to their nature, they are not moved by their nature....Ar
istotle was hard put to discover what,externat to the elements,does produce
their rectilinear motion." Davidson, Proofs for Eremity, Creation and the ex
istence of Gad in Medieval lslamic and }ewish Philosoplry, 265-66.
219
Arisrotle's Physics and lts Mediewil Varieries
fines nature and includes the elements as "by nature"; furthermore, as she
implies, the elements therefore qualify as substance. But Plr,sia 8.4 is a dif
ferent argument. Resolving an objection to his main thesis that motion in
things must be eternal, Aristode intends to establish the proposition "every
thing moved is moved by something." The purpose of the argument cited by
Gill that the elements cannot be self-moved does not show that they are not
substance; it denies that soul serves as the requisite mover-and such a de
nial may well be part œ
Aristotle's anti-Platonism on this point. And the
purpose of the rest of Plr,sia 8.4 is to identify a mover for the elements and
conclude that "everything moved is moved by something." There is nothing
in this argument (or in Plr,sia 2) that requires a thing be a self-mover in
order to be substance, as Gill implies. lndeed, Aristode's first movers (soul
and God), both of which incontestably count as substance, are both
unmooed.
51. Ibid.
220
Nafes to Chapt.er 3
62. Aristotle, Plrysics 2.1. For a fuller examination of this point, see
chapter 5.
63. This point is not made explicit here but is required by the meaning;
cf. Plrysics 3.2.202a5-8; Plrysics 7.1.242b24-26. Weisheipl argues against
this view (his argument is discussed in chapter 6) in "The Specter of the Mo
tor Coniunctus in Medieval Physics."
64. Aristotle uses the word 'tOL<l'U'tT)V, "suchlilce," because they are not
identical but must be distinguished in virtue of being potential and actual.
Cf. Plrysics 3.3.202al2-202b29. This point is so often explained that a bib
liqpaphy of it is practically impossible. One brief, concise, and clear expia
nation may be found in Weisheipl, "Omni quod mmietur," 27.
67. Aristotl�. Plrysics 8.4.255b5: "6!,loLO>c; ÔÈ 'tŒÛ't' ËXEL JCai. bti. 'tÔ>v
'
cj>\J Ô>v "
O LIC
221
Arist.ode's Physics and lts Mtdiewl Variecies
69. Aristotle earlier uses the same example to solve a number of diffi
culties associated with his definition of motion; cf. P"'sia 3.3.202b2-22. For
another instance of Aristotle using learning as an example of natural motion,
cf. Meftll>hysia 9.6.1048a34, 1048b29-34; ll.9.1065bl9-1066a7.
70. For the contrast between Aristotle and Philoponus on this point,
see chapter 5.
74. Aristotle, Arisr.ode's De Anima Books li and Ill, trans. with intro. and
notes by D. W. Hamlyn, 139. Hamlyn notes: "ln sum, Aristotle wishes to
maintain that the intellect in activity is identical with its object." Also, see
R. D. Hicb, trans. inao. and notes to Arisrode's De Anima, 477.
75. Hicks, ibid., comments on the close relation here between "nature
and operation, operation and object" (475).
76. Ross comments on this example: "There is the 6ûvaµ1.1; which pre
cedes the formation of a Ëç1,1;. What transforms this into a Ëç1.1; is a
JtOLT)tl.lc6v, e.g., a teacher teaching a learner." The example of a teacher is
telling-an excellent example of a moving cause. There is no mention of it
in the text and it does not fit the argument here; Ross introduces it only be
cause he presupposes that Aristotle is talking about moving causes, and so
Ross treats Jt01.,rNC6v as if it were virtually a technical term limited in
meaning to "moving cause." Such a reading of JtOLT)tLIC6v is unlikely, espe
cially given the flexibility in terminology for which Aristotle is infamous.
222
Notes to Chapter 3
See Ross, Aristode's Plrysics, 695-96. For Aristotle's use of JtoL'l1:LIC6v in the
context of potency/act relations, cf. Metaplrysics 9.5.1048a6-8: "As regards
potencies of the latter lcind, when the agent [,:o JtOL'11:LIC6v] and the patient
[,:o xa&rrtuc:6v] meet in the way appropriate to the potency in question, the
one must act and the other be acted on . . ." (Oxford translation).
78. For an illuminating analysis of this problem, see J. Owens, "A Note
on Aristotle, De Anima, 3.4.429b9."
223
Arisrode's Physics and lts Mediewl Varieiies
85. Thus at Plrysics 4.4.2llbl3 Aristotle calls place the "form of the
container" and at De Caelo 2.13.293bll-15 refers to it as the "substance of
the cosmos." Cf. also De Caelo 4.3, where place and the elements are closely
associated. I would suggest that rhope is a name for the active orientation of
the elements toward their natural place and their activity when in this place;
cf. De Caelo 2.14.297a8-297bl3; 3.2.30la20-30lbl6; 3.6.305al4-33;
4. l.307b28-308a33.
224
Notes ro Chat,œr 3
an xÉci>'uKÉV XOL, 1ea1. 'tOÛ't' ÉO'tLV 'tO 1eoucj>q> 1ea1. fkxJJEL Etvm, 'tO µÈv ,ip
&v(I) 'tO ÔÈ ,ip KCJ't(I) ôLWp..aµÉvov. ôuvaµEL ô' Èatî.v KOÛcl>ov Kat fkxpù
b
xollaxwc;, O>CfflEP ELP')'tm· ërtav 'tE yàp üôwp, ÔUVClf'EL yÉ xw� ÈatL
ICOÛcl>ov, ICUL O'tUV â1jp, ÉO'tLV O)� É'tL ÔUVCJµEL (ÈVÔÉXE'taL yàp
ȵxooLtcSt,LEvov µ,) èiv(I) Etvm)· àJJ.' Ëàv âcpmpE8� 'tO ȵxoôitov,
È'YEP'YEL ICUL âd Ô'V(l)'tÉpw 'YLyYE'tUL. Ôf'OLù>� ÔÈ ICUL 'tÔ XOLÔV EL� 'tÔ
È'YEP'YEL<f EtVUL 1,LE't«PallEL· EÙ8Ù� yàp 8E(l)pEL 'tO fflL<mpO'V, Èà'Y 1,1.1] 'tL
1((1)�· ICUL 'tO xooôv ÈIC'tEL'VE'taL, Èà'Y 1'11 'tL IC(I)�. 6 ÔÈ 'tO
'Ôq>LO'tCJl&E'Yov Kat JC(l)ÀÛO'V KL'YflO«� ÉO'tLVro�
ICLVEL ÉO'tL ô' ro� oo,
otov ô
'tOV ICLOVU uxooxaoa� fi ô 'tOV À.1.8ov Ôq>EÀ.<À>V MO 'tOÛ âOICOÛ Èv ,ip
üôatL· ICatà ouµPtP'IKÔ� yàp ICL'YEL, &ooEp ICaî. Tl âvadao8Eioa
acj>aipa oùX uxà toû 'to1.xou ÈKLV1J8" àJJ.' ilxà toû Pallovto�."
90. Gill, in Aristode on Substance, argues that "the elements move au
tomatically upward or downward according to their natures, but they stop
moving only because they are compelled to stop. Fire is not programmed to
stop at the periphery; if there were no boundary contained by the fifth ele
ment, fire would continue its upward progression. Similarly, the downward
progress of earth is limited when it reaches the center because it can proceed
downward no further" (239). A full analysis of these conclusions lies beyond
the scope of this study; suffice it to say that Aristotle repeats that a thing rests
only in its natural place and fire rests in its natural place as too does earth;
they are not held by constraint but rest because they have been actualized.
Furthermore, place is not a hindrance, like a wall or pillars holding a roof;
225
Aristode's Physia and lts Medieval Var-.s
place is the form of the container, constitutes the cosmos as determinate, and
so, acts as the actuality ci the elements. See De Caelo 1.8 and 4.3.
92. See below, chapter 6, for the loss ci this cause. For Albert the gen
erator of the element accounts for both motions. On this point Thomas fol
lows Albert; cf. ln Plr,s., VIII, lect. 8, par. 1035. Weisheipl argues that
Thomas (and hence Albert) is right on this point. Weisheipl, "Omne quod
fflOl/etur. ..
97. Bonitz lists at least four major meanings for arche, some of which
may be further subdivided. Bonitz, Index Aristorelicus, 111-13; cf. also
Weisheipl, "Aristotle's Concept ci Nature," 139ff.
102. Aristotle, Plrysics 8.4.256a-2: ". . : (fi yàp i,,i;è, toû yev
fi fi
VT1aavtOc; JCai. xo1.T1aavtoc; KOÛcj>ov �pu, ilxô toû tà ȵxofü�ovta
JCai. JCroÂ.uovta Â.uaavtoc;)••. •."
103. See Weisheipl, "Omne quocl movetur," 52, for this distinction and
some of its medieval reverberations.
227
Arisrotle's Physics and Irs Mediew.d Varieries
113. Richard Sorabji notes that in Physia 8, "Aristotle does not explain
the view of bis later Mtcaphysics that the heavens are alive and that God ex
cites motion in them only as a final cause and object of desire" and suggests
that the argument is incomplete. He then continues: "lt looks as af in the
Physics he already knew the conclusion he thought right, that God, and not
any celestial soul, is the prime mover, but that the tools fur securing this con
clusion were not available to him until he had written the Dt Anima and
Mttaplrysics book 12." Sorabji, Matter, Space, and Morion, 225.
228
Notes to Chapt.er 4
tions of how the question why may be answered. Wieland, "The Problem of
Teleology," 147ff. I would add that the question why is ultimately rcfcrrcd to
things that are by nature, in Plrysics 2.1.
J.
118. For a fairly full analysis of such a view, cf. M. Le Blond, Logique
et méthode chet Aristotle: Étude sur la recherche des principes dans le plrysique
aristotllicienne, "Aporie de la cause motrice," 383-92; also Buckley, Motion
and Motion's God, 58-59. Buckley immediately translates "generator" into
"moving cause" and reviews difficulties of connecting Plrysics 8 and Metaplrys
ics 12, but offers no resolution.
119. Thomas does not explicitly call the generator a moving cause, but
since Aristotle frequently cites the father as a moving cause of the child,
Thomas does seem to mean moving cause. Thomas, In Plrys. VIII, lect. 8,
par. 1032-1033. See Weisheipl, "Omne quocl movetur," who throughout re
peats Thomas's word generator, and Buckley, Motion and Motion's God. For a
modem identification of this view as Aristotle's, see Weisheipl, "The Spec,
ter, " passim.
120. Although this problem lies beyond the scope of this study, it is
taken up later in a difficult text; see De Caelo 3.2.301b17-39. For an example
of the insolubility of these problems as they are traditionally defined, see
G. A. Seeck, "Leich-schwer und der Unbewegte Beweger (DC IV, 3 und
Ph,. VIII, 4)."
.121. This chapter was completed during a leave granted by Trinity Col
lege and supported through a grant from the Mellon foundation to Trinity
College.
229
Arisrode's Physics and lts Medimil Varieâes
fi
tOÛ ICLVOÛVt(X. tOL<l'Ufll 6' toû ICUICÂ.<>U ICi\lTIOL�· ÈICEi 6pa tO ICLVOÛV."
This translation is that of H. O. Apostle, Arutode's Plr,sics: Translated with
Commentaries and Glossary. The Oxmrd translators give a hopelessly unliteral
translation of this passage: "Moreover the movent must occupy either the
centre or the circumference, since these are the first principles from which a
sphere is derived. But the things nearest the movent are those whose motion
is quickest, and in this case it is the motion of the circumference that is the
quickest: therebre the movent occupies the circumference." I shall suggest an
alternate translation below.
6. See Pegis, "St. Thomas and the Coherence"; Pegis devotes much of
his article to an effective refutation of this view.
230
Notes ro Chapter 4
it is always the case; one must also show the first principle in virtue of which
it is always the case.
231
Arisrode's Physics and lts Mediewl Varieâes
19. Compare Plrysics 8.7.260b2-4: "So it is clear that the mover is not
likewise related [to it) but that it is at one time nearer to and at another far•
ther from that which is being altered. . . ." "6Î)ÀO'V oov O'tL tô ICLVOÛV oi,x
OflOLO>C; ÈXEL, àll' Ô'tÈ µÈV ÈyyVtEpov Ô'tÈ ÔÈ 2t0pp0>tEpov tOÛ
àlloLO'Uf.LÉVO\J Èodv."
20. We may note here the inferential force of the particle ÔTI· The
point spelled out follows from the necessary likeness of the first motion to the
first moved.
23. From the opening of the argument at Plrysics 8.7, there are six oc•
currences of the phrase TO nvow .l(\ftL! •• OtL 'tO :n:p<Înov ICLVOÛV ICLVEL ta'U
'tTIV u)v ICLVT)OLv" (7.260a25); "frv ICLVEL tô :n:pôrtov ICLVOÛV" (7.260b29);
"µâALO'ta ÔÈ 6Î)ÀO'V O'tL 'tO ICLVOÛV a'Ù'to avtô µâMota 'tŒ'U'tTIV ICLVEL
ICtlpfu>ç" (7.26la2J-24); "to 61) ICLVOÛV d É'V, i\ ICLVOÛl,LEVOV ICLVEL i\
ÙICL'VYl'tOV &v" (10.267a24-25); ''l'OVTI &pa OUVEX1)ç fiv ICLVEL tô
ÙICL'VYl'tOV" (10.267b16); 11't0 ÔÉ ye :n:p<Înov ICLVOÛV àt6LOV ICLVEL ICL'VYIOLV
acai. lmELpov xp6vov" (10.267b24-25).
232
Notes to Chat,t.er 5
233
ATisrode's Physics and lrs Mediewd Varieàes
m,pi. ct,Épto8a1. frvto· tOÛtO yàp cj>i,mc; J'EV OOIC È<J'tl.V 006' ÈXEI. cj>'U<n.V,
cj>11œ1. 6È 1Cai.1Catà cj>11mv Ëatl'.v. tL µÈVoovÈanv fi cj>11mc;, ELPTtt«1., 1Cai.
tL tà cj>'U<JEI. ICŒL ICatà cj>va1.v."
235
Aristode's Physics and lu Mediewd Varieties
ments, are primary candidates for substance; the problem is to determine the
meaning of "nature."
25. Here Aristotle uses the example of the planted bed, Plrysics
2.1.193al3-15 and 193b10-ll. See A. Gotthelf, "Aristotle's Conception of
Final Causality," for criticisms of a truncated view of Aristotle's teleology that
results from failing to notice these differences between art and nature (227ff).
30. Aristotle rejects the view that the elements might be self-moved,
on the grounds that things that are self-moved contrai the direction of their
movement and can start and stop; see Plrysics 8.4.255a6-8.
34. Cf. Aristotle, De Caelo 4.1.307b32-33: "we call [things] heavy and
light because they are able to be moved naturally in a certain way." Note that
the infinitive is passive here: "Bapù yàp Kat KOÛ«l>ov 'tq> 6ûvaa8m
KLVE'ioeaL +uaLK<Î>� 11:0)� À.É'yOf.LEV."
35. Aristotle, Plrysics 8.4.255bl5: "aL'tLOV 6' (rn 11:Écl>UKÉV 11:0L, Kat
'tOÛ't' Ëcn:Lv 'te> Kov+q> Kat PŒPEi E1vm, 'te> µÈv 1Î\> av0> 'tO ÔÈ 't<\> Ktl'tO>
ÔLO>pLCJI.LÉVOV."
237
Aristade's Physics and les Medimd Yarieries
37. Aristotle, Plrysics 8.4. 255b13-18: "ac:ahot. 'tOÛ'to t'l'tEÎ.'tat., ôt.à 'tL
1tO'tE ICLVEÎ.'tat. d� 'tàv airtÔJv 'i6ffov 'tà ICO\Jct,a ICal. 'tà jklpÉa. QL'tLOV ô'
6tt. xÉcj>uICÉv xot., Kal. 'toÛ't' Ëatt.v 'tÔ Koucj><p ac:al. P<IPEÎ. Etvat., 'tÔ µtv 'tip
(i'Y(J) 'tÔ ÔÈ 'tf\> m'tw &wpt.aµÉvov. ÔUVÔIIEL ô' Ëml.v ICOOcj>ov Kal. jklpù
xoilaxÔ>4;, OMfflEP ELP')'tat.·" Again, see Gill, Aristode on Subsrana, who
argues that because the elements are simple, "their passive principle ade
quately explains their natural motion. . . . Unlilce all other generated bodies
the elements need no active cause to direct their activity or to preserve them.
AU this their material nature can do on its own" (240). Such an account
maltes nonsense not only of Aristotle's argument that "everything moved is
moved by something" but also his definition of motion as an actualization.
oox o
yàp ë, 'tt. Ë't\JXÉV ÈatL 'tÔ &vw, àll' oxou cj>ÉPE't«L 'tÔ x'Ûp 1eal. 'tÔ
ICO'Ûcj>ov· ôµOL<I)� ÔÈ ICal. 'tÔ ICa'tw 'tt. Ë't\JXEV, àll' 6xou 'tà ËXO'Y't«
j3apo� ICQL 'tà YE'IPCl, wc; oil 11 8É<JEL Ôt.acj>ÉpoV'tQ µôvov àllà ICQL 'tlt
ÔUVClf'Et.."
. 47. Aristotle, De Caelo 4.3.310b8-10: "Ë:n;Ei. ô' ô 't6:ito,; Èati. 'tÔ 'tO'll
:itEpLÉXOV'tO,; :n;Épa,;, :itEpLÉXEL ÔÈ :itciV'ta 'tà tcwouµEva avoo tcai. tcci'too 't6
'tE ËoX«'tov tcai. 't<> µÉoov, 'tO'll'tO ÔÈ 'tp6:n;ov 'tLVà y<.yvE'tŒL 'tÔ Etôo,; 'tO'll
:itEPLEXoµÉvou, . . . . "
239
Arisrode's Physics and Irs Mediewd Varieties
ÈvtEÂ.ÉXEL<l'V tàv ËPXE'taL ÈKEÎ. Kat de; 'tO 'toaovtov Kat 'tO wwÛ'tov,
03tOU ilÈvtEÀ.ÉXELa Kat ooou Kai. OLO'U [Kai. 6xou]."
58. For a brief but accurate account of this problem in Aristotle, see
E.M.Macierowski and R.F.Hassing, "John Philoponus on Aristotle's Def
inition of Nature: A Translation from the Greek with Introduction and
Notes," 78-79.
61. Indeed, Philoponus's commentaries are so well known for their pro
lixity that it is impossible not to recall Marsilio Ficino's "excuse for prolixity":
Arisrode's Physics and lts Mediewl Varieries
"Lorenzo, the priest from Pisa, is expounding fur you Solomon 's Song of sangs.
He has 50 far written eighteen volumes, if l remember aright, to explain one
small book. If you are surprised, Cosimo, that Lorenzo wrote 50 lengthily
when Solomon was 50 brief, l reply that Lorenzo was obliged to be lengthy
because Solomon was 50 brief. The more intricate the knot which Solomon
tied, the more devices were necessary to unravel it.
"The distinguished philospher Niccolo Tignosi of Foligno praises
Lorenzo's writings, and I agree with him. Although I usually dislike prolixity,
it does not seem to me that the work is too long, since l find hardly anything
of importance in theology that he has not included within it" in Ficino, The
utten of Marsilio Ficino 48-49.
63. Thomas, ln Plrys., li, lect. l, par. 1#; Vlll, lect. 8, par. 1036. On
Thomas's commentary as literai, cf. Thomas, Commenrary on Aristode's Pla,s
ics, xxi.
65. Aristode, Pla,sics 2. l.192b9-ll; the word soul does not appear in
Pla,sics 2.1, as Aristode proceeds direcdy from this list to the definition of
Noœs ro Chal,ra S
œv
Cf. Philoponus, In Plrys. 194; for the distinction concerning the besouled
and the unbesouled, sec 195.19-24: "Cva EijP'J 'tL ÈotL cj>ÛCM,
MJ1.1Pciw1. 'tLVL 6wcj>Ép€L 'tà cj>uoucà ,w;pa'\'l,la'ta 'tÔ>v µ'l cjn,CJ1.1CÔ>v' 1
yàp liv Ôt.acj>opq Ôt.acj>Ép'J 'tÔ>v µ'l cjn,OLICÔ>v 'tà cl>UOI.ICCl, 'tŒ\J't,, liv
ELTI ci,umJCa. oi'.J'tw 1eai. Èv -riJIlEpi. ,i,uxii� 8w.ov Mlj3Eiv d ÈotLV fi
,vux,\, Ët1\fll<JE 'tLVL füacl>ÉPEL 'tà ˵,vuxa 'tÔ>v à,pÛXO>V, 1eat 1ea8' ô
6wcj)ÉpouOI. 'tOÛO Eb:EV ElvŒL ,vux11v." Although the issue lies beyond this
study, we may note that Philoponus's commentary was undoubtedly influ
enced by that of the Neoplatonist Iamblichus. See Dominic J. O'Meara,
Pychago,m Rem.ied: Mathematics and Philosoplry in Late Antiquit,. 69.
2 43
Arisrotle's Physics and Irs Medieval Varieâes
80. Perhaps this shift lies behind Gill's search for an extrinsic mover for
the elements (Aristotle On Substance, 237-40).
82. When Philoponus was translated into Latin in the sixteenth cen
tury (Aristoteles, Plrysicorum libri quatuor, cum loannis Grammatici cog
nomento philoponi commentariis, quos . . . restituit loannes Baptista
Rosarius, Venice: Hieronymus Scotus, 1558), the text read: "Natura est prin
cipium et causa motus et quietis in eo in quo est primo et per se et non se
cundum accidens (P#rysics, Lib. 2, Cap. 1). This translation does not indicate
Not.es to Chaf,r.er 5
what Philoponus read in the Greek text of Aristotle so much as the enormity
c:i his influence in subsequent readings of Aristotle. I am indebted for this
text to William Wallace, Prelude to Galileo, 123 nn. 3 and 4.
89. Cf. Hahm, The Origins of Stoic Cosmology, 3, 10-11. For a fuller
discussion of Philoponus's relation to the Stoics on this point, cf. Ma·
cierowski and Hassing, "John Philoponus," 84-85.
90. According to Bonitz, this term does not appear in Aristotle's corpus
and appears only once in the pseudo-Aristotelian De Munda 6.397b9; Long
and Sedly discuss this problem for the Stoics in their commentary on 286-
89. On this treatise, see W. L. Lorimer, The Text Tradition of Pseudo-Aristode
'De Munda' Together with an Appendix Containing the Text of the Medieool Latin
Versions. See also, M. Frede, "The Original Notion of Cause," 243-48.
245
Aristode's Physics and lrs Medieval Varieâes
92. For these images in Plato, see Phaedrus 246b-c and Laws
10.897a-c.
97. A full account lies beyond the scope of this essay, but it must be
kept in mind that Plato and the Stoics could hardly differ more on the reality
of soul: for the Stoics it is corporeal, whereas for Plato it is in every way in•
corporeal. They are alike only as malcing body radically dependent upon soul,
in making soul the source of all rational motion, and in accounting for the
cosmos as descending degrees of the same reality (i.e., that bestowed upon
things by soul).
100. lmmortal effects are, of course, the heavenly bodies and their mo
tions. Cf. also, for example, l.aws 10.893c-d.
24 7
Arisrode's Physics and lts Mediewl Varieties
120. Philoponus, In Phys. 499. 6-13, 18-23: "EL tOLVUV tà µÈv &vw
cj>ÉJ>E'tOL cl>U<JEL, tà 6È ICClt(.1), ÈO'tl.V apa cl>VOEI. tô avro 1eai. tô IC(lt(.1),
taûta 6È t6nou füacj>opaL, tô avro tô 1e6.tro tà &!;Là tà àpLO'tEpà tô
˵:rtpoa8EV tô 6ma8EV, O>O'tE O\J µ6vov ÈO'tl. 'tl. 6 T6Jto�. àllà ICŒL
bai.ct,opà� ËXEL (j>um1e6.�. où µ6vov 6É, àllà 1eai. buvaµLv TLV« ÉXEL
auµcj>utov tÔJv t6:rt(l)'V Ë1eaa,:o�· EL yàp Ècj>LEt«L ËICOO'tOV toû ICŒtà
(j>uoLV t6:rtou, ÔT)À.O'V O'tL ICŒ'tà (j>uoLV ÉICO.O'tq> ô t6:rto� ÔJ>EIC't6v 'tL ÈO'tL
ICOL Ècj>Et6v, tO 6È ÔJ>EIC't6v, tq> ÉXELV tLVà 6UVŒµLV cl>UOLIC'tlV, OÜtro�,
ÈO'tLV Ôp€1Ct6v . . . vûv 6È ÈXEL6T) xpo� tô ICÉvtpov 'iJ f)O:rt'tl, füà tOÛto
:rtpo� ôp8à� µ6vro� tJ ICLVT}OI.�. àµÉÀ.EL 1eàv ÈV ÔpU)1.LŒ'tL µEycil.q, :rtÉOYJ
Â.i8o� 1c:aito1. 1c:à.v EL Èy1c:ap0Lro� 'fivéx8t) Èxi. i:riv 6Mt11ta cj>Ep6µEvo�
(xavtax68EV yàp 'iJ 'Y'I
:rtEpLÉXEL), oµw� xpo� ôp8à� µ6vw� '1:0LEL'tŒL
tflV JCLVT}OLV. 1c:à.v EL È1e tÔJv xÂ.ayL(l)'V toû ôpu)1.Lato� à:rtoppayELT)
µ6p1.6v tL, rooavtro� Jta.À.LV cj>ÉJ>EtOL. oütro xâo1. tOL� P«PEOLV mi. 't()
Jc:Évtpov 'iJfJO"'tl· . . . "
The words Ôp€1C't6v and Ècj>Et6v appear in close con
junction in Proclus, Elements of Theology, prop. 8, p. 10.1, 7.
249
Aristode's Physics and lrs Medieval Varieties
128. Cf. Gill, who says that the "use of the preposition ux6 with the
genetive and the passive voice is a usual means of indicating agency in Greek
and the standard grammatical practice is pervasive in Aristotle's treatments
of agency" (Aristode on Subsranœ, 196).
130. Waterlow seems to assert a quite different view (71): "ln other
words, for Aristotle, the concept of 'end' provides not an addiâonal explana
tion, nor one that can eventually be dispensed with, but the onl:, explanation
of somethingaddiâonal (to the materials) in the phenomenon to be explained"
(Waterlow's italics).
S. So, for example, I shall argue in subsequent chapters that Duns's ac
count of place and angels as present to their place is Neoplatonic in charac
ter, as is Thomas's daim that P"1sics 8 leads "up" to its conclusion, God, in
P"1sics 8.10. The issue of Avicenna's influence ob viously lies beyond the
scope of this chapter. Suffice it to say that he apparently invented from hints
in Plotinus (cf. Ennead V I. 2.6) the distinction between essence and exis
tence central to ail Christian medieval philosophy. For a very helpful intro
duction to this problem, cf. Goichon, The Plùlosoplr, of Avicenna (the notes
to this volume by Khan are also very useful.) Since Avicenna knew the Neo
platonic commentators, including Philoponus, the continuity of Neoplatonic
influences in Aristotelianism can hardly be overemphasized. See Sauter, A'1i
cennas Bearbeihmg, S, Sl. On Avicenna himself as a new combination of Ar
istotle and Neoplatonism, see G. Verbeke, A'1icenna: GTundlegeT einer neuen
Meraplrysic (Dusseldorf: Verlag, Rheinisch-Westfalischen Alcademie der Wis
senschafter, 1982), 1-26.
11. The tractate form and its history represents an immense (and very
interesting) topic far beyond the scope ofthis study. For some sense of it, se e
Jacob Neusner, Form-Anal:Ysis and Exegesis: A Fresh Approach to the lnterpre
ration of the Mishnah. Neusner concentrates throughout on a particular trac
tate (Mishna-tractate Makhshirin), so that a good sense ofthe tractate form
emerges. But the form as such is not addressed in a developed way.
253
Arisr.ode's Physics and lts Mediewl Variecies
18. Albert, Liber Vlll Ph,sicorvm, tr. 1, 1, 521a: "utrum sit aliquis mo
tus perpetuus, qui est sicut causa perpetuitatis motus in genere." Although
Albert does not acknowledge it, this discussion may in part originate in
Averroes, Arisrorelis De Ph,sico Auditu Ubri Octo, 338ff, where Averroes ar
gues that Ariatotle is discussing motion in general and not a particular mo
tion. Ali translations are my own.
20. Albert, Liber Vlll Plr,siconan, tr. I, 1, 522a. For the Avicennian
background to this problem and a parallel text from Albert's Summa de crea
uis, see R. de Vaux, NC*s et Textes sur L'Alliœnnisme l..arin aux confins des
Xlle-Xllle Siicles, 55-56.
22. Albert, Liber Vlll Plr,sicorvm, tr. I, 1, 522a: "per hoc quod dicitur
Deus praecedere mundmn duratione, cum aetemitas duratio quaedam sit in
deficiens, et omnino immutabilis." Cf. Augustine, Confessions XI, 13, 15-16;
De Cillirar.e Dei XI, 4-5.
23. An exploration of the point lies beyond the scope of this chapter,
but Albert's God is eternal as a Neoplatonic one is eternal: as a whole, prior
to parts or division into parts, that, because of this priority, is a first cause.
Cf. Augustine, Confessions. XI, 14, 17; De Cillirat.e Dei XI, 6. Motion is eter-
Nor.es to Chaprer 6
nal in a weaker sense, i.e., as a set of parts that are without beginning or end.
And such a set of parts requires a cause that is prior and one.
24. Albert Liber Vlll Plrysicorum, tr. 1, l, 524a: "Non lateat autem nos,
quod cum intendamus probare motum non incepisse in aliquo tempore prae•
terito, neque corrupendum in aliquo tempore futuro, non procedemus nisi
per rationes physicas, quae sunt quod generando incipit quidquid incipit, et
per corruptionem finitur quidquid finitur. Non enim possumus in Plrysicis
probare, nisi quod sub principiis est physicis: et si nos extendamus nos ad lo
quendum de his quae supra physica sunt, non possemus esse physici: quia non
procederemus ex probatis vel per se notis, sed potius transcenderemus ea quae
ratione non valent comprehendi, sicut est creatio et modus creandi omnia
simul et divisim. Physici enim est aut nihil dicere, aut dictum suum demon•
strare per illa quae sunt illi scientiae propria, de qua intendit facere consid
erationem. His igitur sic praelibatis, intendimus probare quod motus
naturaliter nunquam incepit, et naturaliter nunquam deficiet."
25. Ibid.
28. Albert may be borrowing this causal view of Physics 8 from Avi·
cenna and Augustine. See S. M. Afnan, A'1icenna: His Life and Works, 207ff.
This theme is so prevalent in Avicenna that I give only one example here,
Meraplrysices Compendium, l, 3, tr. Il: De Ordine lntelligentiarum Animannn et
Corporum Superiorum ln Essendo, 186-201. lt is also found throughout Au
gustine. See E. J. McCullough, in "St. Albert on Motion as Forma fluens
and Fluxus formoe," discusses this problem, but he attributes this causal view
directly to Aristotle (131). Also, Anneliese Maier, "Die Scholastische We
senbestimmung des Bewegung also forma fluens oder fluxus formae und ihre
Beziehung zu Albertus Magnus," 97-111.
29. Albert, Liber Vlll Plrysicorum tr. l, 2, 524b: ". . . ita quod dicemus,
quod aliquis motus continuus secundum omne tempus inest entibus quae se•
cundum naturam sunt, ut immortalis et inquietus, sicut vita inest his quae
subsistunt secundum naturam: quoniam sicut in unius est anima, cujus actus
continuus in corpus est vita, et non existente anima non existit in animal
ibus vita, ita et motus unus continuus et inquietus causa est influens omnibus
transmutabilibus continuitatem et inquietudinem per hoc quod ipse primus
motus immobilis ex suo motore, et inquietus ex simplicitate sui mobilis et
incorruptibilitate."
255
Aristode's Physics and lrs Mediew.d Varieâes
30. Ibid.
31. Ibid.
32. Again, this theme is Neoplatonic in origin; for brief accounts of its
Avicennian form, see Goichon, The Philosoplry of Allicenna, 25-34, and
Afnan, Allicenna: His Ufe and Worlcs, 207-10.
33. Albert,_ Uber Vlll Ph)siconcm tr. I, 3, 526b: "motus est endelechia,
hoc est, perfectio mobilis sive ejus quod movetur secundum quod movetur."
Albert's definition of motion involves several controversial problems; see
McCullough, "St. Albert on Motion," 129-53.
34. Albert, Uber Vlll Ph)siconcm tr. I, 3, 527a: "Ex his autem omnibus
volumus concludere, quod si nos ostenderimus motum localem qui causa est
omnium motuum, esse perpetuum, quod tune oportebit dare, quod id quod
movet ipsum, est perpetuum secundum substantiam: et id quod movetur ip•
sum esse perpetuum."
39. Cf. Plotinus Ennemi. IV, 4, 20; Augustine, De Gen. ad üu. VII,
15, 21, and 19. lt is often noted that Plotinus, for example, merges the con•
cepts of motion and activity or perfection. For the same issue in Avicenna,
cf. Shifa 1: Sufficientia, Il, c. 4, 27e-f.
41. For Avicenna on this problem, see Afnan, Allicenna: His Ufe and
Worlcs, 207. For one example of this theme, which runs throughout Avi•
cenna, see The Merat,lr,sica of Allicenna (Ibn Sina): A Criiical Tmnslarion
commenrary and anal,sis of the Fundamental Arguments in Allicenna's
Merat,lr,sica in the Danish Nama-i 'ala'i (The Book of Scienâfic Knowfed&e), dist.
39: "Finding in what ways it is possiblè for things to exist and what lcinds of
Not.es to Chaprer 6
things exist, in order to establish how they proceed from the first being" (78);
and dist. 40: "Finding the possibility of being in the modes of perfection
(completeness) and imperfection (incompleteness)" (79).
43. On God as the first cause perfecting the universe, cf. Augustine De
Vera Relipme, 1.
46. Cf. Augustine, De lmmort. Animae 15, 24; also De Civitate Dei XI,
23, 1-2.
47. The first mention of elemental motion appears, although the ar
gument sheds no light on it, at Liber Vlll Plr;ysicorum tr. l, 3, 528b.
50. Albert, Liber Vlll Ph:,sicorum l.4.53lb: "Prima autem forma non
potest educi de materia: quoniam si de materia educeretur, tune oporteret in
choationem ejus esse in materia: sed inchoatio ejus est aliquid formae: ergo
ante primam formam est aliquid formae, quod est impossibile: ergo oportet
quod prima forma sit ab efficiente primo. Constat autem quod nihil praecedit
formam primam ex quo fiat: ergo ipsa per actum causae primae educitur de
nihilo: et sic constat quod primum operatur creando de nihilo: et idea cum sit
sibi potentialis haec operatio, minoratio ipsius potentiae esset si requireret in
primis creatis subjici sibi materiam. lsta tamen disputatio non est physica,
licet sit hic introducta ad eliciendum errorem eorum, qui dicunt mundum
fuisse ab aètemo, et non esse creatum. Sed nos cum consideratione ampliori
tractabimus de his in prima philosophia, ubi quaeremus qualiter fluunt entia
creata ab efficiente primo." See Leo Sweeney, in "The Meaning of Esse in
Albert the Great's Texts on Creation in Summa ck Creaturis and Scripta Super
Senœntias,'' comments that "not much secondary literature has been devoted
25 7
Arisrode's Physics and lrs Mediewl Variecies
to Albert's doctrine of creation" and reviews some, arguing that it suft'ers var
ious confusions. He suggests that this confusion in part rests on the conjunc
tion of Neoplatonic and Aristotelian concepts in Albert (67-72).
53. As this problem lies beyond the interests of this chapter, 1 shall not
examine it. See John M. Quinn, "The Concept of Time in Albert The
Great," for an analysis of this and related texts as well as a helpful bibliog
raphy.
59. Albert, Liber Vlll Plr,sicanan tr. I, 13, 549b: "Et est DIGRESSIO
declarans probationem magis efficacem inter caeteras, quod mundus in
ceperit per creationem."
60. Albert, Liber Vlll Plr,si.corum tr. 1, 13, 549b-550a: "Jam nunc tem
pus esse videtur, ut circa mundi facturam nostram dicamus opinionem, et fi.
dem, et rationibus eam confirmemus quantum possumus. Dicamus ergo
Notes ro Chaprer 6
laudes dandas creatori universi esse, quod mundus a primo creatore solo Deo
incepit per creationem, dicentes etiam tempus et motum cum creatione primi
mobilis incepisse, et cum creatione primi motus qui est primo mobili quod est
coelum intrinsecus."
61. Albert, Uber Vlll Plrysicorum tr. 1, 13, 550b-55la: "ergo habet
perfectissimum modum actionis: sed modus perfectior agendi est agere sine
subjecta materia quam cum materia subjecta: ergo causa prima agit materia
non subjecta: sed materia non subjecta non potest esse generatio: ergo non
agit per generationem, sed potius per eductionem entis de privatione pura
sine negatione quae est nihil omnino: et sic agit de nihilo exisœntia, et sic
creat: quia creare est de nihilo aliquid facere." ln Augustine, cf.Contra Se
cund.Manich. 8; De Gen. ad Litt. lmp. Lib. I, 2; Confessions. XII, 5, 7; XII,
2, 2; De Civiraœ Dei XI, 21-22.
64. Albert, Uber Vlll Plrysicorum tr. 1, 13, 551a: "eo quod generans
producit id quod generatur in similitudine formae et substantiae."
65. Albert, Uber Vlll Plrysiconan tr.I, 13, 551a: "dicimus ... quod
omne compositum quod est terminatum et perfectum per forman perfectio
rem, et œrminatorem suum in forma illa, habet esse extra se."
67. Albert, Uber Vlll Plrysicorum tr. I, 13, 551b: "eo quod nihil diver
sificat materiam nisi quod perficit et terminat eam: nihil autem perficit et
œrminat maœriam nisi forma." ln Augustine, cf.De Gen. ad Litt. I, 4, 9; Il,
1, l; V, 5, 14.
259
ATistode's Physics and lrs Mediewl VMieries
69. For a fuller account c:i Ood's causality in this regard and its close
relation to Neoplatonic concepts, see Sweeney, "Are Plotinus and Albertus
Magnus Neoplatonists?", 197-201. A quite different view is expressed by F. J.
Kovach, "The Infinity of the Divine Essence and Power in the Works of St.
Albert the Great."
70. Albert, Uber Vlll Physiconan tr. 1, 13, 552a: "Ulterius ergo quaero,
utrum elementum ab illa sui causa quae producere ipsam jam probatum est,
producatur sicut a causa agente per naturam et necessitatem, sicut calor pro
ducitur ab igne, aut figura in speculo a luce et objecte speculo, aut producitur
ab ipsa per scientiam et voluntatem et electionem?" Ali Albert's examples
appear throughout Neoplatonic sources. For the most well-lmown text of Au
gustine on Ood's creation through His free will, see De Gen. Cont. Manich.
I, 2, 4 and De Diu Qa,aest. 83.38.
71. Albert, Uber Vlll Physiconan tr. I, 13, 552a: "Nos autem in orbe
magnam videmus divenitatem. Si autem dicatur quod producitur in esse per
electionem et voluntatem, tune poesibile erit, quod sint in magna divenitate
per illam propositionem quam ante probatam sumpsimua, quod agens per vol
untatem liberum est agere actiones divenas: et tune causa diversitatis orbis
non erit nisi sapientia praeordinans et praeconstituens secundum idealem ra
tionem divenitatem orbis."
74. Plato, Timaeus 53b-5. The same theme runs throughout August
ine. For one example, cf. De Vera Relipmt 30, 54-56.
26o
Nota to Chapter 6
77. For Albert, as fur ail Neoplatonists, matter tends to drop out of the
account; first furm is the first level of created reality.
78. Albert, liber VIII Plrysicorum tr. I, 13, 551a. For text, cf. n. 65,
this chapter.
79. Plato's account is cast in entirely different categories, which lie be
yond our topic. See Timaeus 55dff.
82. Albert, liber VIII Plrysicorum tr. Il, l, 558a: "Oportet autem nos
hanc investigationem incipere ab his quae moventur, ut per illa deveniamus
in illa quae movent: eo quod illa quae moventur sunt nobis notiora."
86. Albert, liber VIII Plrysicorum tr. Il, 5, 574a: "Quod omne quod
movetur, reducitur in aliquod movens primum quod movet seipsum."
87. Albert, liber.VIII Plrysicorum tr. Il, 6, 576b: "Quod primo primus
motor est omnino immobilis, ut per hoc concludatur quod id quod est causa
omnis motus, est movens seipsum."
88. This reading would accord with the importance of physics ex
plained within the context of theology. lt appears in·recent scholarship and
bears a striking affinity to Albert's analysis, although his commentary is not
cited; sec M. de Corte, "La Causalité du premier moteur," 173-74 in the re
print edition; J. Paulus, "La Théorie du premier moteur," 283-99; Owens,
"Aquinas and the Proof," 123; Pegis, "St. Thomas and the Coherence," 78,
116-117. Paulus attributes this position to Thomas, a view with which
Owens agrees and that Pegis criticizes. For Avicenna's account of the intel
ligences moving the sphere, sec Avicenna, The Meraplrysics of Avicenna, 52-
53, pp. 96-100.
Arist.orle's Phyaics and les Mtdiewl Varieâes
90. Albert, Liber VIII Plrysiconan tr. Il, 10, 589a: ''Qualiter omne quod
est aliquando, et aliquando non, necessario supponit primum movens, quod
movetsemper et regit ipsum, et quod illud movetur a primo motore immobili,
qui est unus et primus et perpetuus"; Tr. li, 11, 592b: "ln quo ex consider
atione infinitorum probatur primus motor esse immobilis tam perse quam per
accidens: et probatio procedit per conversum modum probationi quae est in
praecedenti capitulo."
92. lndeed, Albert has said that part of the importance of physics as a
science lies here. Cf. above pp. 130.
93. Albert, Liber Vlll Plrysiconan tr. Il, 2, S6Sa-b: "Religuum ergo
membrum superioris divisionis nobis considerandum est, utrum scilicet om
nia entia sint possibilia ad utrumque, ad motum scilicet et quietem: aut
quaedam sint impossibilia ad utrumque horum, et quaedam alia possibilia
semper moventur, et quaedam alla semper quiescunt. Si enim hoc demon
straverimus, sufficienter elucescent omnia membra superioris divisionis. Hoc
igitur demonstrandum est a nobis. Hoc iqitur convenientur facere non pos
sumus, nisi consideremus modos eorum quae movent, duo investigando de
ipsis, quorum unum est, quod omne quod movetur habet motorem, sicut
etiam per modum aliquem minus sufficientem ostendimus in principio sep
timi. Secundum est, quod omne quod movetur secundum locum, reducitur
ad motorem qui non movetur omnino, et tamen est in eo quod movetur se
cundum locum: et hoc est primum movens, et primum mobile."
94. Aristotle, Plrysics 8.6, 8.10; Albert, Liber Vlll Plrysiconan tr. Il, 6
and 11.
97. lndeed this distinction forms the title of this chapter: Albert,
Liber Vlll Plrysiconan tr. Il, 3, 565b: "Quod omne quod movetur, movetur a
motore distincto ab ipso, aut per esse et diffanitionem, aut per diffanitionem
tantum et non per esse."
Not.es to Chapt.er 6
98. Albert, Liber VIII Physicarum tr. Il, 3, 566a: "anima nunquam
movetur per se, nec potest moveri per se: cum ipsa non moveatur nisi in cor
pore: et si separetur a corpore, non erit mobilis motu physico cum sit indi
visibilis secundum quantitatem."
99. Albert, Liber VIII Physicorum tr. Il, 3, 565b: "et quia id quod est
per accidens, quoad nos notius est eo quod est per se, ex abnegatione ejus
quod est per accidens tam in movente quam in eo quod movetur, possumus
congnoscere id quod movet per se, et id quod movetur." See also 567a:
"Declarantes igitur per inductionem omnium eorum quae moventur, quod
moventur a motore distincto a se, incipiemus a magis notis apud nos." This
famous bon mot occurs a number of times in Aristotle but is never associated
with accidentai and essential motion; for example, cf. Aristotle, Physics
l. l.184al7-19; Metaphysics 7.3.1029a35-b5. For a hierarchy of being and
lmowing, see Plato, Republic 6.509e-5lle. On the importance ofa hierarchy
ofbeing in Albert, see Edward P. Mahoney, "Neoplatonism, the Greek Com
mentators, and Renaissance Aristotelianism," 173-74.
100. Albert, Liber VIII Physicorum tr. Il, 3, 566a: "distinctionem au
tem secundum diffinitionem et non secundum esse, quando diffinitio data per
formam entis moventis alia est a diffinitione quae est a forma mobilis: sed
non differunt subjecto et loco: eo quod movens est quaedam forma et per
fectio ejus quod movetur." How two things can be the same in being but dif
ferent in definition is a long-standing problem in the Platonic tradition,
which Albert does not address. lt originates in Plato's doctrine that form (or
soul) is the true being present in becoming but is never united with matter,
which has a reality, and even a definition of sorts, all its own.
101. Albert, Liber Vlll Physicarum tr. Il, 3, 565b: "Quod omne quod
movetur, movetur a motore distincto ab ipso, aut per esse et diffinitionem,
aut per diffinitionem tantum et non per esse." See Tr. Il, 3, 566a: "et intel
ligimus distinctionem secundum esse et diffinitionem, quando movens et
mobile differunt ratione diffinitiva, et etiam subjecto et loco."
moving motion appears later (i.e., is higher in the hierarchy of motions) be
cause it deals with "true" self-motion, that is, the self-motion of soul moving
itself. This motion is self-identical in a way that transcends the distinction
"different in being or different in being and definition." lndeed, as Albert
mentions earlier, it is not a physical motion at ail because it does not involve
quantity. See Liber Vlll Plrysiconcm tr. Il, 3, 566a; see n. 98, this chapter.
104. The elements also present a special problem fur Aristotle. But as
discussed above, the problem is defined entirely differently.
105. Albert, Liber Vlll Plrysicorum tr. Il, 3, 569a: "etiam in elementis
simplicibus forma specifica distinguitur ab essentia materiae." Tr. Il, 3, 569b:
"Jam enim habemus propositum: quia probavimus omne violenter motum, et
omne quod movetur ab anima, et omne quod movetur naturaliter et non ab
anima, et non violenter, ab alio moveri: licet non adhuc probaverimus quod
vel quale sit illud movens quod movet corpora simplicia naturaliter mota, et
ad hoc consequenter ponemus considerationem."
106. Albert, Liber Vlll Plrysiconan tr. li, 3, 569b: "Materia enim ele
mentorum distincta a forma non eat actu aliquo modo: et ideo non potest
eam movere forma: propter quod talia corpora simplicia a seipsis non sunt
mobilia."
107. We may note that Aristotle never mentions furm fur the elements
in Plrysics 8. lndeed, it is not clear that fur him the elements have furm.
Rather, they are simple and continuous, having their actuality in their re
spective natural places.
108. Albert, Liber Vlll Plrysicorum tr. Il, 4, 569b: "Quod omne id quod
movetur natura, et non ab anima, per se movetur a suo generante, et per
accidens ab eo quod removet impedimentum suae actionis."
109. Albert, Liber Vlll Plrysicorum tr. li, 4, 569b; cf. Aristotle, Plrysics
8.4.255a20.
110. Albert, Liber Vlll Plrysiconan tr. Il, 4, 569b-570a: "Si enim ac
cidit id quod natura et non ab anima movetur, ab aliquo a se distincto per
esse et diffinitionem semper moveri, fiet manifestum quoniam in per se et per
accidens secundum naturam et extra naturam fuerint causae diversae quae
sunt magis essentiales motui quae sunt mobile et movens, est etiam in mov
entibus accipere ea quae dicta sunt . . . Exemplum autem eorum quae mov
ent extra naturam et violenter, est in omnibus illis quae non movent ad hoc
ut imprimant ei quod movent furmam suam secundum quam movent, sicut
Notes to Chapt.er 6
vecti in rnachinis qui dicuntur manganelli, vel tribuchi, vel blidae, movent
lapidem; et sic chorda arcus movet sagittam, et sic manus projicit lapidem;
talia enim omnia non sunt natura sua propria moventia grave, sed per im•
petum qui fit in eis, aliunde movent." We rnay note that violent and acci
dentai motion are not identical for Aristotle.
113. Albert, Uber VIII Physicorum tr. II, 4, 570a: "Exemplum autem
eorum quae movent naturaliter, est in omnibus his quae formam secundum
quam sunt moventia, nituntur motu suo imprimere ei quod movent, sicut
actu calidum movet potentia calidum, et sicut anima movet corpus prose·
quendo forrnam quam concepit." Cf. Plato, Laws 10.896e, 897a-b, 900c-
905d, where soul cares for or colonizes body insofar as is possible. Also
Timaeus 35b.
114. Albert, Uber VIII Physicorum tr. II, 4, 570a: "Et quod movetur
secundum naturam, est per se moveri. Et quod movetur violenter, est per
accidens."
115. Albert, Uber VIII Physicorum tr. II, 4, 570a: "Illud autem quod
absolute et simpliciter movetur naturaliter, est illud quod habet in se suscep·
tivam et passivam potentiam recipiendi formam. . . ." For the same notion
in Augustine, cf. De Vera Religione 32, 59-60; De Ub. Arbit. II, 16, 42.
116. Ibid.: "et habet in se tale principium per se, et non secundum ac•
cidens . . . ad quam fuit ordinata potentia ejus. . . . "
117. Ibid.: "sicut potentia quale vel potentia calidum vel frigidum cf.
ficitur actu secundum qualitatem illam informative."
118. Albert, Uber VIII Physicorum tr. II, 4, 570a-b: "Et voco princip·
ium passivum receptum in quo inchoata est forma agentis hoc modo quo dixi
in primo horum librorum, quia omnis forma moventis inchoata est in mate•
ria: aliter enim non est materia propria, neque mobile proprium motori suo
potius quam alii." For an excellent account of inchoate form in Albert and
its origins in Neoplatonic and Arabie philosophy, cf. Bruno Nardi, "La Dot
trina d'Alberto Magno sull' 'lnchoatio Formae.' "
Arisrode's Physics and lrs Mediewl Variecies
119. Albert, Uber Vlll Physiconan tr. Il, 4, 570b: "oportet enim quod
moventia inferant passiones suis propriis mobilibus, et agentia suis propriis
passivis; et hujusmodi passivi et mobilis generale signum est quando in eo
talis invenitur potentia, quae non indiget nisi uno determinato motore ut ex
eat in actum."
120. Albert, Uber VIII Physiconan tr. Il, 4, 570b: "sicut figura hominis
potentia est in semine hominis, et figura idoli potentia est in cupro eo modo
quo cuprum est subjectum arti." For Plato, unlike for Aristotle, nature itself
is a work of art. Albert compares here to Philoponus ( whom Albert did not
know directly).
123. Albert, Uber VIII Physiconan tr. Il, 3, 566a: "et intelligimus dis
tinctionem secundum esse et diffinitionem, quando movens et mobile differ
unt ratione diffinitiva, et etiam subjecto et loco: distinctionem autem
secundum diffinitionem et non secundum esse, quando diffinitio data per for
mam entis moventis alia est a diffinitione quae est a forma mobilis: sed non
differunt subjecto et loco: eo quod movens est quaedam forma et perfectio
ejus quod movetur."
125. Albert, Uber VIII Physicorum tr. Il, 4, 570b: "Dico autem quod
haec potentia insit illi passivo per se, et non secundum accidens."
266
Nota ro Chaf,rff 6
126. Albert, Liber VIII Plrysicorum tr. II, 4, 570b: "quod calor est dis
solvens et extensivus, fit etiam id quod sit calidum majoris quantitatis: hoc
forte non fuit de intentione agentis: sed ideo fit, quia talis extensio accidit
calori quando est in materia dissolubili et extensibili."
129. Albert, Liber VIII Plrysicorum tr. II, 4, 570b. This comment refers
to the related but independent argument of De Caelo 4.
131. Albert, Liber VIII Plrysicorum tr. II, 4, 571a: "Potentia enim pas,
siva quae receptiva est actus et complementi, dicitur dupliciter: quia nos dici
mus, quod secundum alium modum potentiae receptivae est potentia sciens
ille qui adhuc addiscit et eget ut doceatur."
132. Albert, Liber VIII Plrysicorum tr. Il, 4, 571a: "et secundum alium
modum potentia est sciens ille qui jam habet scientiam in habitu, sed non
considerat secundum actum: prior enim qui eget doctrina, non habet poten
tiam in qua fit complementum, nisi per inchoationem: quia est in potentia
sua habitus confusus non adunatus, qui est in primis principiis scientiarum
quae homo scit per naturam. Secundus autem habet habitum, et potest agere
actiones habitus quando voluerit, nisi sit impeditus: et ideo primus est per se
potentiam sciens: sed secundus non est per se potentia sciens in actu, sed po,
tius per accidens impeditur ab opere scientiae: et generale est in utroque is
torum modorum, quod semper sit actu id quod est potentia, quando simul
sunt activum et passivum."
133. Albert, Liber VIII Plrysicorum tr. II. 4, 571b: "Si autem nos
quaeramus quid moveat eum ad considerandum inter duo moventia, scilicet
utrum moveat eum ad considerandum ille qui docet eum et generat in eo sci,
entiam, vel ille qui removet ei impedimentum postquam doctus est, inven
imus quod docens ipsum movet eum per se ad considerandum: quia dat ei
formam, ad quam necessario consequitur considerare si non impediatur: sed
removens obstaculum, movet eum per accidens: quia motus ejus non dat ei
considerare, nisi per accidens: eo quod considerare inerat ei prius si imped
imentum non habuisset. . . . Est autem adhuc intelligendum, quod consid-
Aristode's Physics and les Medietial Varieries
erare secundum actum est a forma scientiae quam iste accipit a sciente: et
ideo quando docens dat ei scientiam, tune cum scientia dat ei omne quod
sequitur ad scientiam: et ideo docens per se movens est in utroque motu, sicut
supra diximus."
136. For a brief account that relates Albert's argument about elemental
motion here in his commentary on the Plrysics to that of his commentary on
the De Caelo, see A. Goddu, "The Contribution of Albertus Magnus To Dis
cussions of Natural and Violent Motion."
138. ln Augustine, cf. De Gen. ad Utt. IX, 15, 27; IX, 16, 29; De Trin•
irate III, 8, 14-15; III, 9, 16; De Civirate Dei XII, 25; XXII, 24, 2. See
Gilson's account of this issue in Christian Philosoplry of Saint Augustine,
206--9.
Notes ro Chaf,œr 6
140. Albert, Liber Vlll Plrysicorum tr. II, 4, 571b -572a: "Cum autem
generatum est et accipit formam calidi, et fit ignis, tune operabitur opera
tionem calidi, quae est ardere, nisi habeat aliquid quod ipsum impediat ab
operatione: unde ab eo a quo accipit formam ignis et caloris, ab eodem ac·
cipit omnem operationem et omnem proprietatem, quae sequitur formam ig•
nis et caloris."
141. Albert, Liber Vlll Plrysicorum tr. Il, 4, 572a: "Grave enim primum
potentia est leve, et tali potentia quam vocamus per se potentiam passivam
et receptivam, in qua per inchoationem solam est forma levis."
142. Albert, Liber Vlll Plrysicorum tr. li, 4, 572a: "Signum autem hujus
est, quia nos videmus quod quantum generans ei quod generatur, largitur de
sua forma, tantum largitur ei de suo loco et de suo motu." Closing the argu·
ment, 572b, Albert repeats his point in even stronger language: "Causa au
tem quare moventur in propria loca quando non sunt prohibita, nulla alia
est, nisi quia ex forma accepta a generante ipsa apta nata sunt inesse, et non
alibi ubi sunt sua generantia, et hoc esse forma levi et gravi: unde per essen•
tiam est leve sursum, et grave deorsum, et levi sursum moveri, et gravi de•
orsum moveri, sicut diximus."
143. Albert, Liber Vlll Plrysicorum tr. li, 4, 572a: "et ideo locus et mo
tus datur a generante sicut forma: sed forma datur principaliter, et locus et
motus dantur per consequens, sicut ea quae propria accidentia sunt formae
datae per generationem."
146. James A. Weisheipl argues against the view that Aristotle requires
a mover in contact with the moved and so concludes that on this point "the
teaching of Albertus Magnus and Thomas Aquinas is no different from that
of Aristotle himself." Weisheipl, "The Spe cter."
Arisrode's Physics and lu Mediewl Varieâes
147. Albert, Liber Vlll Plrysicorum tr. Il, 4, 572b-573a: "Illud autem
quod est movens sive removens id quod sustinet et prohibet generatum ne
agat operationem suae formae, illud potest dici movens et non movens."
148. Albert, Liber Vlll Plrysicorum tr. Il, 4, 573a: "et similiter movet
ipsum generans dando ei formam, dat ei omnia formam generantis conse
quentia. Sed auferens impedimentum movet ipsum per accidens nihil dando
sibi, sed tantum impediens id quod jam inest ea removendo. Jam enim per
formam sibi datam inest ei esse illud quod per se consequitur formam datam,
licet impediatur ab exteriori."
149. Albert, Liber Vlll Plrysicorum tr. Il, 5, 574a: "Quod omne quod
movetur, reducitur in aliquod movens primum quod movet seipsum."
150. Albert, Liber Vlll Plrysicorum tr. Il, 4, 573a: "Manifestum igitur
ex dictis est, quod nihil horum simplicium corporum movet seipsum, sicut
antiquitus opinatus est Plato, et post eum Galenus, et in processu temporis
Seneca."
151 . Ibid. "Sed omnia talia sui motus in se habent principium, non qui
dem movendi se active et faciendi et recipiendi hoc a generante ipsa, et dante
eis formam cujus est motus et locus ad quem moventur."
152. Albert, Liber Vlll Plrysicorum tr. Il, 4, 573b: "Et similiter ea quae
non moventur a seipsis et moventur natura, ut gravia et levia, moventur et ab
aliquo motore, qui distinctus est ab eis per esse: quia aut moventur a gener
ante et faciente leve et grave in forma levis et gravis, aut ab eo quod solvit et
removet ab eis impedientia et prohibentia, ut agant actum gravis et levis.
Omnia igitur quae moventur, ab aliquo movebuntur distincto ab ipsis per dif
finitionem et esse, aut per diffinitionem solum: et hoc est quod volumus
declarare."
153. Albert, Liber Vlll Plrysicorum tr. Il, 4, 573b: "Nec aliquis miretur
si tantam quaestionem determinamus per inductionem. . . . "
270
Notes ro Chapter 7
16. On the history of this problem and possible solutions to it, see
Pegis, "St. Thomas and the Coherence," 67-117.
17. On this point, see H. Lang, "Aristotle's First Movers and the Re#
lation of Phy sics on Theology."
20. lt is not known when or by whom the logoi comprising the Plrysics
were compiled and set in their present form. Here I am suggesting only that
the internai evidence shows that the present order is the right order.
Notes to Chaprer 7
21. On the literai commentary, its relation to teaching and the daim
that it does not reflect the persona( views of the teacher, cf. A. Kenny and
J. Pinborg, "Medieval Philosophical Literature," 29-30.
22. Thomas, In Phys. Vlll, lect. 23, par 1172. Ali references are to In
Octo Libros Physicorum Aristotelis Expositio.
23. For a clear sense of how Aristotle's argument that motion in things
must be eternal has become both linked to the problem of God's causality
and problematic as an Averroistic teaching, see Gilson, Christian Philosophy
of St. Thomas Aquinas, 147, and Owens, "Aquinas as Aristotelian Commen
tator," 231-32.
27. Thomas, ln Phys. Vlll, lect. l, par. 965; cf. lect. 5, par. 1104.
28. Cf. Thomas, ln Phys. Vlll, lect. 5, par. 1004; lect. 23, par. 1172.
29. Thomas, In Phys. I, lect. 1, par. 3: "de his vero quae dependent a
materia non solum secundum esse sed etiam secundum rationem, est Natu•
ralis, quae Physica dicitur. Et quia omne quod habet materiam mobile est,
consequens est quod ens mobile sit subiectum naturalis philosophiae." This
statement contrasts with Aristotle in Physics 2.2.194bl3: "The physicist is
concerned only with things whose forms are separable indeed, but do not
exist apart from matter." Thomas's point may be more directly drawn from
Meraphysics 7. ll.1036b23-1037b7. Ali translations are my own.
30. See J. Owens, "Aquinas and the Proof," 148-150. Owens con•
cludes that "Thomas tends to view the whole proof in a strongly metaphysical
setting" (149).
273
Arisrode's Physics and lts Medieval Variecies
31. Thomas, ln Plrys. Ill, lect. 1, par. 275: "Postquam Philosophus de
terminavit de principiis rerum naturalium, et de principiis huiius scientiae,
hic incipit prosequi suam intentionem determinando de subiecto huius scien
âae, qu.od est ms mobile simpljciter."
32. Thomas, ln Plrys. IV. lect. 1, par. 406: "Postquam Philosophus de
terminavit in tertio de motu et infinito, quod competit motui intrinsece, se
cundum quod est de genere continuorum, nunc in quarto libro intendit
determinare de iis quae adveniunt motui extrinsece. Et primo de iis quae ad
veniunt motui extrinsece quasi mensurae mobilis."
34. Thomas, ln Plrys. IV. lect. 11, par. 520; cf. lect. 12, par. 536.
35. Thomas, ln Plrys. IV. lect. 12, par. 534; on the wider context of this
problem for Thomas and his trcatment of it, see J. A. Weisheipl, "Motion in
a Void: Aquinas and Averroes,'' 467-88.
42. On this point, see, for example, Murdoch, "lnfinity and Continu•
ity,'' 575 n. 33; Edward Grant, "Scient�fic Thought in Fourteenth-Century
Paris: John Buridan and Nicole Oresme," 110.
Notes to Chapter 7
50. Thomas, In Plrys. Vlll, lect. 22, par. 1160: "primo enim ostendit
quod propter diversitatem motorum, deficit continuitas vel unitas motus, in
quibusdam mobilibus quae videntur continue moveri."
51. Thomas, In Plrys. VIII, lect. 22, par. 1163: "quia non habet unum
et idem determinatum movens, sed moventia diversa."
53. Ibid. For an English translation of this text, see Marshall Clagett,
Mechanics, 532-38. lt is beyond the scope of this chapter to provide a full
bibliography of this problem. For a basic introduction to the issues at stake
here, see Clagett, Mechanics, 505-25 and 538-40: the latter commentary is
also reprinted by Grant, Soun:e Boole, 278-80: see E. A. Moody, "Laws of
Motion," 197-201, and A. Maier, Zwei Grundproblmie der scholastischen
Nanaphilosophie, 201-14. On the dissemination and influence of Buridan in
central Europe, cf. M. Markowski, "L'influence de Jean Buridan sur les uni·
versités d'Europe centrale." Gilson comments that the "influence of Buridan
went far beyond what we can imagine." Gilson, History of Christian Philosophy
in the Middle Ages, 795.
275
ATisrode's Physia and lts Medieval VtJTiecies
54. Buridan, Q. Plrys. VIII, 12, fol. 120; Clagett translation, 532.
quam Deus est praesens omnibus. Aut intendit concludere illam praesentiam
quae competit Deo in quantum est immensus, et tune ex operatione ali
cubi-secundum ipsum-sequitur praesentia illa quae pertinet ad immensi
tatem divinam (quae est Dei in quantum Deus est), ita quod prius naturaliter
erit Deus praesens in quantum immensus quam in quantum operans; et hoc
concluditur ex hoc quod est praesens per operationem, sicut ex posteriore
prius. lgitur a simili in proposito, prius naturaliter erit angelus praesens alicui
loco per essentiam, quam sit praesens sibi per suam operationem."
17. Duns Scotus, Ordinacio 2, dist. 2, pars 2, q. 2, par. 204-5. For par.
204, see n. 12, this chapter; for par. 205, see n. 16, this chapter. The issue
here between "contact" and "presence" is at least as old as the relation be
tween Aristotle and Stoic philosophy; cf. E. Bréhier, "la Théorie des incor•
porels dans l'ancien stoïcisme," esp. 116-19.
18. Duns Scotus, Ordinacio 2, dist. 2, pars 2, q. 2, par. 219; see n. 5 this
chapter. Cf. Aristode, Ph,sics 4.4.212a21.
19. For a general discussion C1 place according to Duns Scotus, cf. Du
hem, Le Sysrhne du monde, 6.207-13.
20. Duns Scotus, Ordinaâo 2, dist. 2, pars 2, q. 2, par. 224: "Dico igitur
quod locus habet immobilitatem oppositam motui locali omnino, et incor-
218
Noœs ro Chat>œr 8
21. Ibid., par. 227: "Secundum probo, quia licet locus corrumpatur
moto eius subiecto localiter, ita quod, moto aere localiter, non manet in eo
eadem ratio loci quae prius (sicut patet ex iam probato), nec eadem ratio loci
potest manere in aqua succedente, quia idem accidens numero non potest
manere in duobus subiectis,-tamen illa ratio loci succedens (quae est alia a
ratione praecedente) secundum veritatem est eadem praecedenti per aequiv
alentiam quantum ad motum localem, nam ita incompossibile est localem
motum esse ab hoc loco in hune locum sicut si esset omnino idem locus nu
mero. Nullus autem motus localis potest esse ab uno 'ubi' ad aliud 'ubi,' nisi
quae duo 'ubi' correspondent duobus locis differentibus specie, quia haben
tibus alium respectum-non tantum numero sed etiam specie,-ad totum
universum; ex hoc illi respectus qui sunt tantum alii numero, videntur unus
numero, quia ita sunt indistincti respectu motus localis sicut si tantum essent
unus respectus."
23. Of course, for Aristode, the relation is not arbitrary at ail. The
elements and place go together as potency and actuality.
24. Duns Scotus, Ordinario 2, dist. 2, pars 2, q. 2, par. 229. "Sic dico
in proposito quod locus est immobilis per se et per accidens, localiter,
tamen est corruptibilis moto subiecto localiter, quia tune non manet in eo
illa ratio loci; et tamen non est corruptibilis in se et secundum aequivalen
tiam, quia necessario succedit illi corpori-in quo fuit illa ratio loci-aliud
corpus, in quo est alia ratio loci numero a praecedente et tamen eadem
praecedenti secundum aequivalentiam per comparationem ad motum lo
calem." On Ockham's analysis and understanding of Duns Scotus on this
point, cf. H. Shapiro, Motion, Time, and Ploce accmdmg to William Ockham,
124-25.
279
ATistotle's Physics and lts Mediewl VaTieâes
31. Duns Scotus, Ordinaâo 2, dist. 2, pars 2, q. 2, par. 231; see n. 27,
this chapter.
33. Duns Scotus, Ordinaâo 2, dist. 2, pars 2, q. 2, par. 231; cf. n. 27,
this chapter. Also cf. Gilson, Hisror, of Chrisrian Philosoplry. 409ff,
37. Duns Scotus, Ordinaâo 2, dist. 2, pars 2, q. 2, par. 231 (see n. 27,
this chapter).
38. Ibid., par. 236: "Ad propositum igitur ista applicando, de angelo,
dico quod angelus non necessario est in loco, quia multo magis posset fieri
Notes to Chapter 8
sine creatione creaturae corporalis, vel facta creatura corporali posset fieri et
esse extra omnem creaturam corporalem. Et tamen in angelo est potentia
passiva, qua potest esse in loco; et ipsa potentia vel fundatur immediate in
eius substantia, vel in ipsa in quantum est natura limitata actualiter existens,
vel in aliquo extrinseco angelo (quidquid sit illud). Et ideo non oportet
quaerere aliquam intrinsecam rationem essendi angelum in loco, necessario,
quia ibi nulla est,-sed tantum est in ipso potentialitas passiva, qua potest
esse in loco quia non repugnat sibi." On potency, see A. B. Wolter, The
Transcendentals and TheiT Function in the Metaphysics of Duns Scotus, 145-48.
39. Duns Scotus, Onlinatio 2, dist. 2, pars 2, q. 2, par. 232: "De se
cundo articule dico quod-supposito primo--corpus 'quantum' est in loco in
actu, quia in praecise continente actualiter; non enim potest esse in loco,
quin illud ultimum (quod est proximum continens) faciat illud actu, quia
facit latera corporis continentis distare. Secus autem est de parte in toto,
quae non facit superficiem in potentia continentem, ipsam in actu; et ideo
non est pars in toto sicut locatum in loco ([V Ph,sicorum)."
41. Ibid., par. 237: "Supposito igitur isto primo, non oportet quod sit
in loco in actu, quia non oportet quod sit in aliquo continente indivisibili
actualiter existente; non enim facit latera continentis distare, et ideo non
facit superficiem continentem esse in actu."
42. Ibid., par. 233: "De tertio dico quod-propter eandem quanti·
tatem-necessario coexigit corpus locum sibi aequalem.
"Et propter illud est in loco commensurative, ita quod pars superficiei
contentae correspondet parti superficiei continentis, et totum toti."
43. Ibid., par. 245: "De quarto patet quod non est in loco commen
surative, quia non habet partem et partem cum parte loci."
45. Ibid., par. 246: "De quinto dico quod est in hoc loco vel in illo,
quia non est ubique. Et huius ratio quaerenda est.
"Dico quod licet aliquid possit esse secundum se in potentia passiva ad
aliquod genus physicum, et non determinate in potentia ad aliquam speciem
illius generis, tamen ab eodem reducitur illud ad actum generis et speciei:
sicut, licet superficies (unde superficies) sit ex se determinata ad colorem, et
non sit ex se determinata ad albedinem vel nigredinem, tamen ab eodem
281
Arisrotle's Physics and lts Medieval Varieiies
agente reducitur ad actum coloris et huiusmodi coloris, quia non est colorata
nisi quia sic est colorata. lta dico hic quod licet angelus sit in potentia ad 'ubi'
in communi, et non ex se determinatus ad hoc 'ubi' vel illud, tamen ab eo
dem agente reducitur ad hoc ut sit actualiter in loco, et in hoc loco vel in illo
adesse quo primo est in loco, producente ipsum supra creaturam corporalem
continentem; sed ex tune potest se ipsum reducere ad actum istum, sicut
patebit in quaestione de motu angeli."
48. Ibid., par. 247: "De sexto dico quod non est in loco aliquo natu•
raliter, quia tune esset in alio loco violenter; tune etiam aliquod corpus
haberet naturalem habitudinem ad ipsum conservandum in loco, et aliud
corpus ad ipsum corrumpendum."
50. Duns Scotus, Ordinatio 2, dist. 2, pars 2, q. 2, par. 238: "De tertio
autem est dubium, et de hoc mota est secunda quaestio. Conceditur tamen
quod non potest esse in loco quantumcumque magno, quia hoc est proprium
Dei. Et ex hoc videtur non posse esse in loco quantumcumque parvo, ex 35
1 Euclidis; vult enim ibi Euclides,-quaere eum ibi."
51. Ibid., par. 239-40: "Ex hoc arguo sic: quidquid potest esse in uno
aequali, potest esse in altero, si sibi non repugnat figuratio aliqua secundum
quam unum distinguitur ab alio; sed in angelo nulla figuratio loci, in quo est,
sibi repugnat; igitur si potest esse in uno aequali, et in altero,-et per con
sequens, si potest esse in quadrato parvo, et non repugnat sibi esse in
quadrato quantumcumque stricto (quod oportet dicere, dicendo quod non re
pugnat sibi esse in quantocumque loco), videtur quod non repugnat sibi esse
in loco quantumcumque longo, quia quadrangulus est aequalis ipsi quadrato
parvo, in quo potest esse.
"lstud declaratur per oppositum in corpore naturali. ldeo enim aqua,
quae potest esse in quadrato, non potest esse in quadrangulo quantumcumque
Nora ro Chapœr 8
longo, quia non potest esse in loco quantumcumque stricto; et ideo non
potest quantumcumque protendi secundum magnitudinem: non enim potest
protendi secundum longitudinem nisi constringatur secundum latitudinem,
et si non potest in infinitum constringi secundum latitudinem, non potest in
infinituni protendi secundum longitudinem. Oppositum est in proposito: si
enim angelus non determinet quantumcumque locum in minus (quia tune
poterit esse in loco quantumcumque stricto et strictiore), igitur etc."
52. Ibid., par. 239-42. For par 239-40, see n. 51, this chapter. Par.
241-42 reads: "Praeterea, si quantitas aliqua virtutis est in angelo secundum
quam potest esse in aliquo loco proportionaliter secundum ultimum poten•
tiae suae (puta iste tantum et ille tantum), posset tamen secundum ultimum
potentiae suae facere se in minore isto quantumcumque, sibi adaequato (hoc
autem 'posse' est alicuius virtutis activae in eo, quia in potestate sua est ut
possit ea uti ad effectum sibi adaequatum, vel non),-igitur magis posse
habere istam quantitatem in potestate sua, est perfectius, quia maiorem habet
potentiam activam: et ita est potens uti ista virtute activa in infinitum, ad
causandum vel essendum in minore et minore loco quam sit ille locus sibi
adaequatus; igitur potentiam habet infinitam. Consequens est inconveniens,
igitur et antecedens; sicut igitur si posset in infinitum esse in maiore et
maiore loco, concluderetur infinitas virtutis eius, ita concludetur infinitas
virtutis eius si posset esse in loco minore et minore semper in infinitum.
"Si tamen posset esse in puncto, vel non,-non videtur ratio neces
saria ad unam partem nec ad aliam: quia licet sit indivisibilis, non tamen
habet indivisibilitatem limitatem sicut punctus, et ideo non oportet ipsum
esse in puncto sicut in loco; nec forte repugnat sibi esse in puncto sicut in
loco, quia nullum inconveniens videtur ex hoc inferri,--quia si ex hoc in•
feratur quod non posset moveri localiter nisi spatium esset ex punctis, non
sequitur (posset enim immediate ex loco punctali facere se in continuum,
cuius continui punctus est terminus)."
53. Ibid., par. 249: "Ex isto sexto patet quod ista potentia passiva (quae
est in angelo ad essendum in loco) non est naturalis nec violenta, sed neu•
tra,--quia nec istud passum inclinatur ex se naturaliter ad istam formam, nec
ad oppositum, sed neutro modo se habet ad ista, sicut superficies ad albed
inem vel nigredinem indifferenter se habet."
56. The question of how many angels can dance on the point of a nee
dle, or the head of a pin, is often attributed to "lare medieval writers." ln his
standard reference work, Mencken refers it to "various writers c. 1400." ln
point of fact, the question has never been found in this form and, l believe,
may not exist. lt stands as a jibe and represents a hostile attitude toward ail
discussions like this one in Duns. Such hostility is not characteristic of
fourteenth-century Scotists such as John of Ripa, William Alnwiclc, or Rob
ert Cowton. (For a good bibliography of these Scotists, cf. Gilson, Hisr.ory of
Christian Philos<>Ph, 763-73.) For an outstanding example of a serious argu
ment against the Scotist position, see the writings of William of Ockham,
where the problem of angels in place is treated very seriously in itself and is
also connected with problems conceming transubstantiation; cf. De Sacm
mento, chaps. 11-14, 16, 25-30. Rather, hostility toward this type of ques
tion occurs only in much later post-Renaissance thinlcers for whom these
discussions seem remote and obscure. Hence we can speculate that the jibe
concerning angels dancing on the point of a needle is a general reference to
discussions lilce this one in Duns and the responses that it generated, rather
than a specific reference to a question quoted directly.
58. Ibid., 8.
59. This problem is, of course, notorious in Descartes and one of the
major areas of criticism by his detractors. For the classic texts, cf. Meditaâons
on First Philosoplry. Meditation VI letter to Regius, mid-December 1641, and
letter to Princess Elizabeth in response to her letter of 6/16 May 1643. These
may be found in any standard edition of Descartes's worlcs.
Bibliography
Texts of Aristotle
Aristotle's De Anima Books Il and Ill. Translatcd with introduction and notes
by O. W. Hamlyn. Oxford: Clarendon Press, 1968.
Aristode's Plr,sics: Boolcs I and li. Translated with introduction and notes by
W. Charlton. Oxi>rd: Clarendon Press, 1970.
Aristode's Plr,sics: Boolcs Ill and IV. Translated with notes by E. Hussey. Qx.
ford: Clarendon Press, 1983.
Albertus Magnus. Plr,siœrum Libri. Vol. 3 of Alberti Magni Opera omnia. Ed
ited by Borgnet. Paris: Vives, 1890-99.
Averroes. Aristot.elis De Plr,sico .Audicu Libri Octo. Venice: Junctas, 1562. Vol.
4 in Aristot.elis Opera Cum Allffl'Ois Commentariis. Venice: Junctas,
1562-1574. Reprint by Minerva, 1962.
Oiels, H. Die Fmpienr.e deT VOTSokmtilcer, GTiechisch und Deutsch. 5th ed. Ed
ited by E. Kranz. Berlin: Weidmann, 1934-37.
Galen.
· On Natvral Faculties. Greek text, and English translation by A. J.
Broek. The Loeb Classical Library. New York: G. P. Putnam, 1916.
Proclus. The Elements of Theolog,. 2nd ed. Revised text, with translation and
commentary by E. R. Dodds. Oxford: Clarendon Press, 1963.
Modern Authors
Afnan, S. M. Allicenna: His Life and Works. London: George Allen & Un
win, 1958.
Ashley, Benedict M. "St. Albert and the Nature of Natural Science." ln Al
bertus Magnus and the Sciences: Commemorative Essays 1980, edited by
James A. Weisheipl, 73-102. Toronto: Pontifical lnstitute of Medieval
Studies, 1980.
Bréhier, E. "La Théorie des incorporels dans l'ancien stoïcisme." Archi11 fwr
Geschicht.e der Philosophie 22 (1909): 114-25.
tiraire dumoyen•·
D'Alvemy, M.-T. "Avicenna Latinus, I-X." Archwes d'lùsr.oiR doctrinale et lit
Vols. 29-37. 1962-70.
Aristode's Physics and lts Mediewl Varietia
-- . Proofs for EternitJ, Creation, and rite Exisrenœ of Ood in Mediewd Is
lamic and Jewish Philosoplr,. Oxford: Oxford University Press, 1987.
de Vaux, R. Notes et Textes sur L'A'1iœnnisme Latin aux confins des XIIe-XIIIe
Siècles. Paris: Vrin, 1934.
Dunphy, W. B. "St. Albert and the Five Causes." ArcMltS d'histoire doclTinal.e
et littbaire du Mo,en Age 33 (1966): 7-21.
Ebbesen, Sten. "Proof and lts Limits according to Buridan, Summulae 8." In
Pmic.oe et raisons à l'Uni11e1Siré de Paris: Logique, ontologie, et théologie au
XIVe Sièck, edited by Z. Kaluza and P. Vignaux, 97-110. Paris: Vrin,
1984.
Fakhry, Majid. "The Arabs and the Encounter with Philosophy." ln Arabie
Plùlosoplry and the West: Continuït, and Interaction, edited by Therese
Anne Drurat, 1-17. Washington, D.C.: Georgetown University Cen
ter for Contemporary Arab Studies, 1988.
Ficino, Marsilio. The Letters of Marsilio Ficino. Translated from the Latin by
members of the Language Department of the School of Economies.
Vol. 1. London: Shepheard-Walwyn, 1975.
2 93
Arisrode's Physics and lts Mcdieval Vcarielies
Frede, M., "The Original Notion of Cause." ln Doubt and Oogmaiism, edited
by M. Schofield, M. Burnyeat, and J. Bames, 217-49. Oxford: Clar
endon Press, 1980.
Gersh, Stephen. Midt:fk Platonism and Neoplaronism: The Latin Tradition. Vol.
1. Notre Dame: University ci Notre Dame Press, 1986.
Orabmann, Martin. "Der Einfluss Alberts des Orossen auf das mitterlalter
liche Oeistesleben." ln Miu.elalrerliches Geisresltben: .Abhandlungen tur
Geschicltte der Scholastik und M:ystilc, vol. 2. Munich: M. Hueber, 1936.
295
Aristode's Physics and lts Mediewl Vcarieâa
297
Aristode's Physics and lts Mtdiew.d Varietia
The Cambr•
Kenny, Anthony, and Jan Pinborg. "Medieval Philosophical Literature." ln
Hisror, of Lato- Mediewl Plùlosoplry: From the Redisc:owry
of Arisrode ro die Disintegraâon of Schowrü:ism, 1100-1600, edited by N.
Kretzmann, A. Kenny, J. Pinborg, and assoc. ed. E. Stump, 10-42.
Cambridge: Cambridge University Press, 1982.
Konstan, David. "Points, Lines, and lnfinity: Aristotle's Plrysia Zeta and
Hellenistic Philosophy." In � of the Bosron Area Colloqwium in
Ancieni Philosophy, edited by John J. Cleary, vol. 3, 1-32. New York:
University Press of America, 1988.
Kovach, F. J. "The lnfinity of the Divine Essence and Power in the Worlcs of
St. Albert the Great." ln Albert des Grosse: Seine Zeit, Sein Werlc, Seine
Wirlamg, edited by Albert Zimmerman, 24-40. Vol. 14 of Miscellanea
Mediaevalia. New York and Berlin: Walter De Gruyter: 1981.
Kramer, Joel. "A Lost Passage from Philoponus' Contra Arisrotelem in Arabie
Translation." American Journal of Oriental Studies 85 (1965): 318-27.
Lang, Helen S. "Aristotle's First Movers and the Relation of Physics to The
ology." New Scholasticism 52 (1978): 500-517.
-- . "God or Soul: The Problem of the First Mover in Plrysics VII." Pai
deia: St>tcial Arisrode Issue 52 ( 1978): 86-104.
300
-- • Die Vor'li.iu.fer Galileis. Rome: Edizioni di Storia e Letteratura, 1949.
McVaugh, Michael. "A List of Translations Made from Arabie into Latin in
the Twelfth Century." ln Sourceboolc in Medie1,al Science, edited by Ed
ward Orant, 35-38. Cambridge: Harvard University Press, 1974.
Miller, Fred D., Jr. "Aristotle against the Atomists." ln lnfinir, and Conti
mdty in Ancient and Medie1,al Tlwught, edited by N. Kretzmann, 87-
111. lthaca, N.Y.: Comell University Press, 1982.
301
Aristade's Physics and lu Mtdieval Varielies
Murdoch, John E., and Edith D. Sylla. "The Science ci Motion." ln Science
in the Mid& �. edited by D. C. Lindberg, 206-64. Chicago: Uni
versity ci Chicago Press, 1978.
Neusner, Jacob. Form-Analysis and Exegesis: A Fresh APf1rOaCh t.o the lnterpre
taâon ,f the Mislmah. Minneapolis: University of Minnesota Press,
1980.
302
Bibliogra,,h,
303
Arisrode's Physics and lrs Maliewd Varieries
Pegis, A. C. The Middle Ages and Philosoplry. Chicago: Henry Regnery, 1963.
Preiffer, Rudolf. History of Classical Scholarship: From the Beginnings ro the End
of the Hellenistic Age. Oxford: Clarendon Press, 1968.
Pines, S. "�tudes sur Awhad al-Zaman Abu'l Barakal al-Baghdadi." Rewe des
etudes
}uitJeS 103 (1938): 33-64; 104:1-33. Reprinted in Studies in
Abu'l-Barakat Al-Baghdadi Pleysics and Metaplrysics: The Collected Works
of Shlomo Pines, vol. 1, 1-95. Jerusalem: Magnes Press, 1979.
-- . "Omne quod movetur necesse est ab aliquo moveri: A Refutation of
Galen by Alexander of Aphrodisias and the Theory of Motion." ISIS
52 (1960): 21-54. Reprinted in Studies in Arabie Versions of Greek Texts
and in Mediewù Science: Collected Works of Shlomo Pines, vol. 2, 218-51.
Jerusalem: Magnes Press, 1986.
Quinn, John M. "The Concept of Time in Albert the Great." ln Albert the
Great Commemorative Essa,s, edited by F. J. Kovach and Robert W.
Shahan, 21-47. Norman: University of Oklahoma Press, 1980.
Ross, W. D., Aristode. 5th ed. Oxford: Methuen and Co., 1949.
Shapiro, H. Motion, Tnne, and Place according ro William Ockham. St. Bon
aventure: Franciscan lnstitute, 1957.
3o6
BibliogrtJl>lr,
Sweeney, Leo. "The Meaning of Esse in Albert the Great's Texts on Creation
in Summa de Creaturis and Scripra Super Sententias. " ln Albert the Great
Commemorative Essa,s, edited by F. J. Kovach and Robert W. Shahan,
65-96. Norman: University of Oklahoma Press, 1980.
307
Arisrode's Physics and lrs Mediewl Varieries
Synan, E. A. "Brother Thomas, the Master, and the Masters." In St. Thomas
Aquinas 1274-1974: Commemorative Studies, editor in chief A. Maurer,
vol. 2, 219-42. Toronto: Pontifical lnstitute of Medieval Studies,
1974.
-- . Friar Thomas D'Aquino: His Ufe, Thought, and Work. New York:
Doubleday, 1974.
-- . "The Life and Works of St. Albert the Great." ln Albertus Magnus
and the Sciences: Commemorative Essays 1980, edited by James A.
Weisheipl, 13-51. Toronto: Pontifical lnstitute of Medieval Studies,
1980.
Wengel, P. M. Die Lehre wn den raâones seminales bei Albert dem Gros.sen:
Eine r.erminologisch und �he Unrersuclumg. Würzburg:
Buchdruckerei Richard Mayr, 1937.
310
Bibliography
311
Index of Nam.es
313
Arisrode's Physics and lrs Mmwl Varaa
314
Index of Nomes
Plato,4-6; 6,n. 20; 7-8; 8,n. 33; 26; Solmsen,F.,3; 3,n. 6; 6,n. 24; 35,
26,nn. 31-32; 27; 27,nn. 34- n. 4; 42,n. 38; 44,n. 45; 52,
37; 28; 28,nn. 43-48,51; 33; nn. 78,81; 59, n. 47
35-37; 40; 40,nn. 23-27; 41; Sorabji,R.,7,n. 30; 15,nn. 51,
41,n. 29; 42-44; 44,n. 45; 50; 59,60; 27; 38; 80,n. 99;
56; 69,n. 47; 98; 101,n. 28; 83,n. 113,98,n. 10; 106,
106,n. 59; 112,nn. 91-93; 96; n. 59; 120,n. 122
113; 113,nn. 97-100; 125,n. l; Stanford,W. B.,33; 33,nn. 74-77
131,nn. 40,42; 133,n. 55; 136; Sweeney,L.,125,nn. 2,3; 135,n. 69
136,n. 73; 137; 137, nn. 74-75; Sylla,E. D.,64,n. 5; 172,n. 59
138,n. 79; 140; 146, n. 121; Synan,E. A.,158,n. 156
151; 153; 156-57; 159
Plotinus,125,n. 5; 131,n. 39; 146
Plutarch,112,n. 88 Taylor,A. E.,69,n. 47
Pocock,L. G.,32,n. 69 Tempier,E.,18; 175; 180
Pohle,W.,69,n. 47 Themistius,81; 82; 82,n. 112
Praechter,K.,106,n. 60 Theophraatus,37,n. 9
Proclus,41,n. 29 Thomas Aquinas,2; 14; 17; 41,n. 29;
42,n. 40; 46,n. 50; 47; 47,
n. 60; 79,n. 92; 84,n. ll9; 86,
Quinn,J. M.,133,n. 53 n. 3; 107; 107,n. 63; 133,n. 57;
140,n. 88; 153,n. 146; 161-
171; 161,n. l; 164,n. 22; 187
Raven,J. E.,44,n. 46
Robert Cowton,187,n. 56
Robinson,T. M.,40,n. 23 Verbelœ,G.,16,n. 64; 35,n. 4; 46,
Rose,V.,35,n. 2 n. 53; 51,n. 77; 54,nn. 90,92;
Ross,W. D.,3,n. 3; 4,nn. 8-9; 35, 125,n. 5
nn. 2-3; 36; 43; 43,n. 41; 46, Verryclœn,K.,98,n. 8
nn. 51,54; 47; 47,n. 57; 49, Vivanti,P.,32,n. 71
n. 64; 52,n. 82; 75,n. 76; 79, Von Arnim,H.,37,n. 9; 54,n. 92
n. 91; 85,n. 2
Wieland, W., 10; 10, nn. 42-43; 83, Wolfson, H. A., 6, n. 25; 82, n. 105;
n. 115 83, n. 116; 85, n. 2; 133, n. 58;
Wildbcrg, C., 3, n. 4 181, nn. 28, 32
William Alnwick, 187, n. 56
William ofOclcham, 187; 187,
nn. 55-56 Zcllcr, E., 3, n. 2; 35, n. 2
Wippcl, J., 162, n. 5 Zimmcrman, F., 98, n. 11; 107, n. 62
Wolff', M., 83, n. 116; 100, n. 20; 103,
n. 41, 108, n. 71; 112, n. 91
317
Index of Subjects
Earth, 64, 69, 72, 98-99, 101-2, 108, infinite power 176, 187
116, ll8, 120, 122-23, 128, 138, immensity, 176
152, 176. See also elements; stone moving cause, 12
center, 79, 93, 125, 134-35, 147-48 object of love, 60
Elements,63-64, 67, 69, 70-72, 76- omnipresence, 176, 186-87
84, 93, 98-99, 101-3, 106-8, thinking on thinking, 60
114-23, 125, 128,132-37, 139, unmoved mover, 105
141-44, 147-48, 150-53, 155, Oravity, 187
158-59, 176, 179. See also earth; Orowth, 104
air; fire; water
End, 54. 124, 136-38, 147, 164-65,
168. See also Final cause Habit, 73-75, 77-80, 82, 84, 148-
Etemity, 129 50, 153
Evaporation, 76, 79 Heaven(s), 60, 85, 87, 110, 116-17,
"Everything moved is moved by some• 128, 136, 138, 140, 148, 176,
thing", 9, 35-37, 39-53, 55-61, 179-82
64, 66-69, 72, 75, 79, 81-82, Hindrance, 74, 77-81, 100-1, 105,
89, 93, 99, 108, 123, 140-41, 137, 139, 144, 149, 151, 153-54
153-55, 177, 186
Extension, 42, 113, 119, 121
Ignorance, 77
lmpediment. See Hindrance
Final cause, 54, 63--64, 83, 124. See lmpetus, 64, 144-45, 171
also End Inclination, 16, 103-8, 112-15, ll7-
Fire,64,69-70,72,76,84,98-99, 101- 22. See also rhope; impetus; furce
2, 105, 108, ll6, 118, 120-23, lncrease, 88, 105
125, 134-35, 138-39, 147-48, lnfinite, ·ity, 9, 24, 44-49, 51, 53, 56,
151-53, 180. See also Elements 66, 163, 166, 176
Force, 64, 112, 145, 151, 170, 187 Intellect, 133
Form, 23, 25-26, 30-31, 41, 99-101, lnterval, 121
103-6, 108-15, ll7, 121-23,
132-38, 143-49, 151-54, 156,
158, 185 Knowledge, 73, 77-79, 115, 135,
Free will, 128, 135-39, 157-58, 149-50
183, 186 acquisition of, 73
exercise c:J, 73, 75-77
320
Index of Subjects
Materialism,•ists,24,33 Moved,first,35-36,44,52-53,56,
Mathematics,25 59-60,65-66,87,92-93. See
Matter,23,25-26,31,99-102,105-6, also Heavens
108-14,121,123, 132-35,137- Mover(s),accidentai,68
38,143,146,167,176-77,181 essential,69,71,81-82,101-2,
Mishna,126 128,146,170,177
Motion,62,73,84-85,88,97-98, extrinsic,intrinsic,37,53,107-8,
100-1,lll-13,117,124-25, 110-11,114-15,117-18,120-
127,130-31,139,141,145-46, 23,143
152,155-57,160,167,169-70. first,4,12,18,35-37,44,48-50,
See also locomotion 52-59,63,65-66,83,85-94,
accidentai,68,109,141-44 127,133,139-42,155-56,
animate,69,80-81,133,142 164-66
continuous,86,88-91,130 moved,44-53,56,58
definition of,9,14,24,57,59-60, natural,70-71,119
82-83, 88,137-39,169 problem of,16,64, 107-8
elemental,72,73-80,84,99,104- unnatural,70-71
5, 114-19,122,126,128-30, unmoved, 60,65,67,90-91,110,
133-34,136,138-39,142-45, 156,163-64,166,168
147-48. 150-52,154-55,157- Moving cause,54, 63-64,83,124
58,160,179,181
essential,68,80,141-45,147,149 Nature,8,14,24-25,31,33-34,61,
eternal,eternity of,11,12,18,57, 80,82,97-117,119-21,123-24,
59-61, 63-67, 81-83, 86,88- 129,134-36,138,146,153,
89,94,127-34,140,158, 157-58,160,166-67,183
163-65 definition of,16,23,29,162
first,11,66-67,86-89,92-93,165 innate principle of motion,24-27,
first cause of,ll,40, 43,45 163-64,166-67,169.
first principle of,3,4 Necessity, 135-36,179
inanimate,67,69,73,79-81 Neoplatonic,Neoplatonism,2,14-17,
intrinsic principle of,8 lll,125-26, 129-32, 150-52,
of a magnitude,91-92 154,156-60
natural,69,70-73,77,79-81,99,
101,103-5,110,114,138-39, Perfection,136-38
141,145,151,153,171,179 Phantasm,133
a perfection in the moved,130-32 Physics,principles and objects,8,97,
perpetual,129-30 100,134,163-65,178,181
projectile,169-70 science of,10,13,19,25,63,65-
special terms required by,9 66,68,80,86,88,92-94,115-
source of,3 7,68 16,121,126-30,132, 136,138-
unnatural,69,72. See also 41,147. 154-60,162,164,166-
violent motion 69,171-75,179-87
violent,69,80-81,141,145,151, Place,9,24,64, 69,72,76-82,84,
153,179. See also unnatural 87,102-7,115-22,135,137-38,
wholes and parts, 36,38-43,46, 147,151-55,163,166-67,
51-52,55, 57,59,61 174-87
321
ATistode's Physics and lu Mec:fiewl VaTieâes
322