Kant-Metaphysics SC
Kant-Metaphysics SC
Kant-Metaphysics SC
Stanford Encyclopedia
of Philosophy
1
Kant’s Critique of Metaphysics
connection, Kant denies that the principles or rules of either general logic
(e.g., the principle of contradiction), or those of his own “transcendental
logic” (the pure concepts of the understanding) by themselves yield
knowledge of objects. These claims follow from Kant’s well-known “kind
distinction” between the understanding and sensibility, together with the
view that knowledge requires the cooperation of both faculties. This
position, articulated throughout the Analytic, entails that independently of
their application to intuitions, the concepts and principles of the
understanding are mere forms of thought which cannot yield knowledge of
objects.
analytic” (cf. A247/B304). Filling this out, Kant suggests that to take
ourselves to have unmediated intellectual access to objects (to have “non-
sensible” knowledge) correlates with the assumption that there are non-
sensible objects that we can know. To assume this, however, is to conflate
“phenomena” (or appearances) with “noumena” (or things in themselves).
The failure to draw the distinction between appearances and things in
themselves is the hallmark of all those pernicious systems of thought that
stand under the title of “transcendental realism.” Kant’s transcendental
idealism is the remedy for these.
immortality of the soul, freedom, and the existence of God. Despite their
contributions to metaphysical illusion, Kant tells us that the goals and
interests in question are unavoidable, inevitable, and inherent in the very
nature of human reason. In the Introduction to the Transcendental
Dialectic Kant thus introduces “reason” as the locus of these metaphysical
interests.
Although the demand for the unconditioned is inherent in the very nature
of our reason, although it is unavoidable and indispensably necessary,
Kant nevertheless does not take it to be without problems of a unique sort;
for the very same demand that guides our rational scientific inquiries and
defines our (human) reason is also the locus of error that needs to be
curbed or prevented. In connection with this principle, then, Kant also
identifies reason as the seat of a unique kind of error, one that is essentially
linked up with metaphysical propensities, and one which he refers to as
“transcendental illusion [transzendentale Illusion].” Kant identifies
transcendental illusion with the propensity to “take a subjective necessity
of a connection of our concepts…for an objective necessity in the
determination of things in themselves” (A297/B354). Very generally,
Kant’s claim is that it is a peculiar feature of reason that it unavoidably
takes its own subjective interests and principles to hold “objectively.” And
it is this propensity, this “transcendental illusion,” according to Kant, that
paves the way for metaphysics. Reason plays this role by generating
principles and interests that incite us to defy the limitations of knowledge
already detailed in the Transcendental Analytic. The Introduction to the
The need for this critical reinterpretation stems from the fact that reason’s
demand for the unconditioned cannot be met or satisfied. The absolutely
“unconditioned,” regardless of the fact that it presents to reason as
objective, is not an object or state of affairs that could be captured in any
possible human experience. In emphasizing this last point, Kant identifies
metaphysics with an effort to acquire knowledge of “objects” conceived,
but in no wise given (or giveable) to us in experience. In its efforts to
bring knowledge to completion, that is, reason posits certain ideas, the
“soul,” the “world” and “God.” Each of these ideas represents reason’s
efforts to think the unconditioned in relation to various sets of objects that
are experienced by us as conditioned.
For more on Kant’s theory of illusion, see Allison (2004), Butts (1997),
Grier (2001, forthcoming), Neiman (1994), Theis (1985), Bird (2006). See
also Ameriks (2006), Dyck (2014).
The claim that the ‘I’ of apperception yields no object of knowledge (for it
is not itself an object, but only the “vehicle” for any representation of
objectivity as such) is fundamental to Kant’s critique of rational
psychology. Kant thus spends a considerable amount of time arguing that
no object is given in transcendental self-consciousness, and thus that the
rational psychologist’s efforts to discern features of the self, construed as a
metaphysical entity, through reason alone are without merit. To elucidate
the ways in which the rational psychologist is nevertheless seduced into
making this slide from formal representations of self consciousness to a
metaphysics of the self, Kant examines each of the psychological
arguments, maintaining that all such arguments about the soul are
dialectical. He refers to the arguments designed to draw such conclusions,
“transcendental paralogisms”, and hence the chapter of the Critique that
criticizes rational psychology goes by the name “The Paralogisms of Pure
Reason.” A transcendental paralogism, according to Kant, is a “syllogism
in which one is constrained, by a transcendental ground, to draw a
formally invalid conclusion” (A341/B399). Kant’s subsequent efforts are
thus directed towards demonstrating the paralogistic (fallacious) nature of
the arguments about the soul.
Kant locates the equivocation contained in the argument in the use of the
term “substance.” According to Kant, the major premise uses this term
“transcendentally” whereas the minor premise and conclusion use the
same term “empirically.” (A403). What Kant appears to mean is this: the
major premise deploys the term “substance” in a very general way, one
which abstracts from the conditions of our sensible intuition (space and
time). As such, the major premise simply offers the most general
definition of substance, and thus expresses the most general rule in
accordance with which objects might be able to be thought as substances.
Nevertheless, in order to apply the concept of substance in such a way as
to determine an object, the category would have to be used empirically.
Unfortunately, such an empirical use is precluded by the fact that the
alleged object to which it is being applied is not empirical. Even more
problematically, on Kant’s view, there is no object given at all. In Kantian
jargon, the category only yields knowledge of objects if it is
“schematized,” applied to given objects under the conditions of time.
There are four “antinomies” of pure reason, and Kant divides them into
two classes. The first two antinomies are dubbed “mathematical”
antinomies, presumably because in each case, we are concerned with the
relation between what are alleged to be sensible objects (either the world
itself, or objects in it) and space and time. An important and fundamental
aspect of Kant’s rejection of each of these sets of arguments rests on his
view that each of these conflicts is traceable back to a fundamental error,
an error that can be discerned, according to Kant, in the following
dialectical syllogism:
This hypostatization of the idea of the world, the fact that it is taken to be
a mind-independent object, acts as the underlying assumption motivating
both parties to the two mathematical antinomies. The first antinomy
concerns the finitude or infinitude of the spatio-temporal world. The thesis
argument seeks to show that the world in space and time is finite, i.e., has
a beginning in time and a limit in space. The antithesis counters that it is
infinite with regard to both space and time. The second antinomy concerns
the ultimate constitution of objects in the world, with the thesis arguing for
ultimately simple substances, whereas the antithesis argues that objects are
infinitely divisible. In this, the thesis positions are each concerned to bring
the explanatory effort to a close, by arguing for ultimate or, as Kant says,
“intelligible beginnings” (cf. A466/B494). The claim that there is a “first
beginning” or an ultimately simple substance is sustained only by
abstracting from the spatio-temporal framework. The alleged proponent of
the antithesis arguments, on the other hand, refuses any conclusion that
goes beyond the sensible conditions of space and time. According to the
antithesis arguments, the world is infinite in both space and time (these
being infinite as well), and bodies are (in accordance with the infinite
divisibility of space) also infinitely divisible.
How does Kant demonstrate this? Both the thesis and antithesis arguments
are apagogic, i.e., that they constitute indirect proofs. An indirect proof
establishes its conclusion by showing the impossibility of its opposite.
Thus, for example, we may want to know, as in the first antinomy, whether
the world is finite or infinite. We can seek to show that it is finite by
demonstrating the impossibility of its infinitude. Alternatively, we may
demonstrate the infinitude of the world by showing that it is impossible
that it is finite. This is exactly what the thesis and antithesis arguments
purport to do, respectively. The same strategy is deployed in the second
antinomy, where the proponent of the thesis position argues for the
necessity of some ultimately simple substance by showing the
impossibility of infinite divisibility of substance, etc.
uses the term “the conditioned” in a very general way, one that considers
things in abstraction from the sensible conditions of our intuition. The
minor premise, however, which specifically refers to objects in space and
time (appearances), is committed to an empirical use of the term. Indeed,
such an empirical use would have to be deployed, if the conclusion is to be
reached. The conclusion is that the entire series of all conditions of
appearances is actually given. Put in other terms, the conclusion is that
there is a world, understood as the sum total of all appearances and their
conditions (A420/B448).
In both cases the thesis opts for a position that is abstracted from the
spatio-temporal framework, and thus adopts the broadly Platonic view.
The postulation of freedom amounts to the postulation of a non-temporal
cause, a causality outside the series of appearances in space and time
(A451/B479). Similarly, in its efforts to argue for a “necessary being,”
The resolution to these antinomies here consists in giving each side its
due, but simultaneously limiting the domain over which the claims hold.
The thesis demand for an absolute causal beginning or a necessary being
might well be allowed to stand, but certainly not as “part of” or as an
explication of appearances in nature. Similarly, the antithesis conclusions
can stand, but only in relation to objects in nature, considered as
appearances. Here, the conflict seems irresolvable only on the assumption
that appearances are things in themselves. If appearances were things in
themselves, for example, then it would certainly seem true that either they
are one and all subject to mechanistic causality, or not. In such a case, it
makes sense both to argue for a non-temporal beginning and to deny such
a beginning. Left unresolved, then, this antinomy leaves us wit the
following dilemma: on the assumption of transcendental realism, both
spends a considerable amount of time tracing the idea of God back to its
rational, speculative, sources. According to Kant, “….the Ideal …is based
on a natural, not a merely arbitrary idea” (A581/B607). On this score,
Kant wants to tell us that we are compelled to think the idea of God (the
ens realissimum) when pursuing certain speculative or philosophical
interests. More specifically, the idea of a supremely real being (the ens
realissimum) is one to which we are inevitably led during our attempts to
account for the pure possibility of things in general. The upshot that the
idea of the ens realissimum is not an arbitrary or easily dispensable one.
Instead, Kant suggests that reason is philosophically constrained to move
to such an idea in its efforts to thoroughly determine every thing. Such
efforts require thinking the totality, or “All” of reality (the omnitudo
realitatis). Such an idea is philosophically required because, in our efforts
to thoroughly determine each thing (to know it completely, specify it
exhaustively), we must be able to say, of every possible predicate and its
contradictory (p v ˜p) which of the two holds of the thing in question. (For
every object, it is either A or not A, either B or not B, etc., and this process
is iterated until each predicate pair (each positive reality) is exhausted —
Kant clearly has a Leibnizian procedure of complete determination in
mind here.) This process is parasitic upon the idea of “sum total of all
predicates of things in general.” Or, put in another way, we represent
“every thing as deriving its own possibility from the share it has in the
whole of possibility” (A572/B600). Such an idea, the All of reality,
however, defines itself as an individual thing, and leads us to the
representation of the “supremely real being.” The problem seems to come
in, according to Kant, when the “All” of reality gets hypostatized, and
(eventually) personified, thus yielding the ens realissimum (cf.
A583/B611n). Here again, Kant thinks that this idea itself gets transmuted
into the notion of a given object by virtue of a unique subreption, whereby
we dialectically substitute for a principle that is only meant for empirical
employment one which holds of things in general. The argument Kant
offers is excruciating, but the essential point is that, just as the idea of the
soul involved the subreption of the hypostatized consciousness, so too, the
idea of the ens realissimum is generated by both a subrepted principle and
a hypostatization.
Thus, although Kant is most well known for his attacks on the specific
arguments for God’s existence, his criticisms of rational theology are in
fact more detailed, and involve a robust critique of the idea of God itself.
This account of the rational origin and the importance of the idea of God
clears the way for Kant’s rejection of the metaphysical arguments about
God’s existence. Kant identifies three traditional arguments, the
ontological, the cosmological, and the physico-theological (the argument
from design). What all such arguments do is attempt to wed the idea of the
ens realissimum with the notion of necessary existence. Whereas the
Ontological argument moves from the concept of the ens realissimum to
the claim that such a being exists necessarily, the Cosmological and
physico-theological arguments move from some necessary being to the
conclusion that such a being must be the ens realissimum.
1. God, the ens realissimum, is the concept of a being that contains all
reality/predicates.
2. Existence is a reality/predicate.
3. Therefore God exists.
At the heart of this complaint is a more general one, to wit, that there is a
problem with the attempt to infer anything as necessarily existing.
Although, according to Kant, reason is unavoidably led to the notion of an
absolutely necessary being, the understanding is in no position to identify
any candidate answering to the idea. (cf. A592/B620). Clearly, the
ontological argument is designed to show that, in fact, there is one (and
only one) candidate answering to this idea, namely, the ens realissimum.
But it does so by deducing the necessary existence from the concept of the
ens realissimum (a being that contains all reality or predicates) only via
the minor premise that “existence” is a predicate or reality. Kant, however,
famously denies that existence is a “real predicate,” or determination.
Thus, one criticism is that the argument conflates merely logical with real
(determining) predicates. A real (determining) predicate is one that
enlarges the concept to which it is attached. It seems clear that the locus of
the error here, as in the other metaphysical disciplines, is the view that the
idea of the ens realissimum provides us with a concept of an “object” to
which it would be appropriate to apply categories or concepts in a
determining way. Thus, included in Kant’s criticism is the claim that the
category of existence is being subject to a transcendental misemployment
(A598/B626). This misapplication of the category is problematic precisely
because, according to Kant, we are dealing only with an object of pure
thought, whose existence cannot be known (A602/B630).
If the ontological argument seeks to move from the concept of the ens
realissimum to the concept of an absolutely necessary being, both the
cosmological and physicotheological proofs move in the opposite
direction. Each, that is, argues that there is something that must exist with
absolute necessity and concludes that this being is the ens realissimum.
Because these proofs aim to identify the ens realissimum with the
necessary being, and because the attempt to do this requires an a priori
argument (it cannot be demonstrated empirically), Kant thinks that they
are both (ultimately) vitiated by their reliance on the ontological proof.
More specifically, they are both mitigated by their assumption that the ens
realissimum is the only object or candidate that can do the job of existing
necessarily. Since he thinks that the ontological argument is in some sense
implicitly relied upon in making such a claim, these arguments stand or
fall with it. On Kant’s view, as we shall see, they fall.
The cosmological proof has, according to Kant, two parts. As above, the
proponent of the argument first seeks to demonstrate the existence of an
absolutely necessary being. Second, the rational cosmologist seeks to
show that this absolutely necessary being is the ens realissimum.
As above, the theist will ultimately want to identify this necessary being
with the ens realissimum, an identification which Kant thinks
surreptitiously smuggles in the (dialectical) ontological argument. The
claim here is that the proponent of the cosmological argument is
committed ultimately to accepting the ontological argument, given her
attempt to identify the necessary being with the ens realissimum. Although
this suggests that the cosmological argument relies on the ontological,
Kant also indicates that the effort to produce a purely a priori argument
for God’s existence (the ontological argument) itself gets momentum from
reason’s need to find the necessary ground for existence in general, a need
expressed in the cosmological argument (cf. A603–04/B631–32). This
suggests that Kant takes the ontological and cosmological arguments to be
complementary expressions of the one underlying rational demand for the
unconditioned.
Even aside from its alleged commitment to the ontological argument, Kant
has a number of complaints about the cosmological argument. Indeed,
according to Kant, the cosmological argument is characterized by an
“entire nest of dialectical presumptions” which must be illuminated and
Kant’s claim is that even if we could grant that the order and
purposiveness of nature gives us good reason to suppose some intelligent
For some discussions of the Ideal of Pure Reason and Rational Theology,
see Caimi (1995). England (1968), Grier (2001, forthcoming), Henrich
(1960), Longuenesse (1995, 2005), Rohs (1978), Walsh (1975), and Wood
(1978), Chignell (2009), Grier (2010), Chignell (2014), Wuerth (2021),
Willaschek (2018)
Kant is quite clear that he takes reason’s demand for systematicity to play
an important role in empirical inquiry. In connection with this, Kant
suggests that the coherent operation of the understanding somehow
requires reason’s guiding influence, particularly if we are to unify the
knowledge given through the real use of the understanding into scientific
theory (cf. A651–52/B679–80). To order knowledge systematically, for
Kant, means to subsume or unify it under fewer and fewer principles in
light of the idea of one “whole of knowledge” so that its parts are
exhibited in their necessary connections (cf. 646/B674). The idea of the
form of a whole of knowledge is thus said to postulate “complete unity in
the knowledge obtained by the understanding, by which this knowledge is
to be not a mere contingent aggregate, but a system connected according
to necessary laws” (A646/B676). Having said this, it should be noted that
Kant’s position is, in its details, difficult to pin down. Sometimes Kant
suggests merely that we ought to seek systematic unity of knowledge, and
this merely for own theoretical convenience (A771/B799-A772/B800).
Other times, however, he suggests that we must assume that the nature
itself conforms to our demands for systematic unity, and this necessarily, if
we are to secure even an empirical criterion of truth (cf. A651–53/B679–
81). The precise status of the demand for systematicity is therefore
somewhat controversial.
It is connection with this that Kant argues, in the second part of the
Appendix (“On the Final Aim of the Natural Dialectic of Human Reason”
(A669/B697)), that the three highest ideas of reason have an important
theoretical function. More specifically, in this section Kant turns from a
general discussion of the important (regulative) use of the principle of
systematicity, to a consideration of the three transcendental ideas (the
Soul, the World, and God) at issue in the Dialectic. As examples of the
unifying and guiding role of reason’s ideas, Kant had earlier appealed to
the ideas of “pure earth” and “pure air” in Chemistry, or the idea of a
“fundamental power” in psychological investigations (cf. A650/B678).
His suggestion earlier was that these ideas are implicit in the practices
governing scientific classification, and enjoin us to seek explanatory
connections between disparate phenomena. As such, reason’s postulations
serve to provide an orienting point towards which our explanations strive,
For discussions on the Appendix and the role of reason and systematicity,
see Allison (2004), Brandt (1989), Buchdahl (1967), Britton (1978),
Forster (2000), Friedman (1992), Ginsborg (1990), Grier (2001,
forthcoming), Guyer (1990a, 1990b), Horstmann (1989), O’Neill (1992),
Patricia Kitcher (1991), Philip Kitcher (1984), Nieman (1994),
MacFarland (1970), Walker (1990), Walsh (1975), Wartenberg (1979,
1992), Rauscher (2010), Willaschek (2018).
Bibliography
Relevant Works by Kant (includes German editions and
translations):
Unviersity press.
Rauscher, F., 2010, “The Appendix to the Dialectic and the Canon of Pure
Reason: The Positive Role of Reason,” in P. Guyer (ed.) 2010, pp.
290–309.
Rohs, P., 1978, “Kants Prinzip der durchgangigen Bestimmung alles
Seienden,” Kant-Studien, 69: 170-180.
Sellers, W., 1969, “Metaphysics and the Concept of a Person,” in The
Logical Way of Doing Things, ed. K. Lambert, New Haven: Yale
University Press: 219–232
–––, 1971, “…This I of He or It (the Thing) which Thinks…” Proceedings
and Addresses of the American Philosophical Association 44: 5–31
Powell, C. T., 1990, Kant’s Theory of Self-Consciousness, Oxford:
Clarendon Press
Proops, I., 2010, “Kant’s First Paralogism,” Philosophical Review, 119:
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Strawson, P.F., 1966, The Bounds of Sense: An Essay on Kant’s Critique of
Pure Reason, London: Methuen.
Theis, R., 1985, “De L’illusion transcendentale,” Kant-Studien, 76: 119-
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Theil, U., 2006, “The Critique of Rational Psychology,” in Bird (ed.)
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Van Cleve, J., 1981, “Reflections on Kant’s Second Antinomy,” Synthese,
47: 481–494.
Velkley, R. 1989, Freedom and the End of Reason: On the Moral
Foundations of Kant’s Critical Philosophy, Chicago and London:
University of Chicago Press.
Walker, R., 1990, “Kant’s Conception of Empirical Law,” Proceedings of
the Aristotelian Society (Supplementary Volume), 64: 243–258.
Walsh, W. H., 1975, Kant’s Criticisms of Metaphysics, Edinburgh:
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Wartenberg, T., 1979, “Order Through Reason,” Kant-Studien, 70: 409-
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–––, 1992, “Reason and the Practice of Science,” in Cambridge
Companion to Kant, ed. Paul Guyer, Cambridge: Cambridge
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Watkins, E., 1998, “Kant’s Antinomies: Sections 3–8,” Kooperativer
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Willaschek (eds.), Berlin: Akademie Verlag: 445–462
–––, 2000, “Kant on Rational Cosmology” in Kant and the Sciences, ed E.
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Wilson, M., 1974, “Leibniz and Materialism,” Canadian Journal of
Philosophy 3: 495–513
Willaschek, M., 2018, Kant on the Sources of Metaphysics: The Dialectic
of Pure Reason, Cambridge: Cambridge University Press.
Wuerth, J., 2010, “The Paralogisms of Pure Reason,” in P. Guyer (ed.)
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–––, 2021, The Cambridge Kant Lexicon, Cambridge: Cambridge
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–––, 1978, Kant’s Rational Theology, Ithaca: Cornell University Press.
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Wood, A. (ed.), 1984, Self and Nature in Kant’s Philosophy, Ithaca:
Cornell University Press
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