Powerful Modality

British Journal of Undergraduate Philosophy Powerful Modality* Ben Page University of Oxford Introduction What account of truth-makers for modal statements is best? In this paper I defend a powerful theory of modality, which is rooted within an ontology of powers. This gives a ‘hardcore actualist’ account of modality and I argue that it is superior to the modal realist and platonic approaches. Having contended that this approach should be preferred, I seek to answer some objections one might raise against the account, eventually contending that a combined theist and power account answers the objections most convincingly, whilst also providing some possible responses for those who don’t wish to embrace theism. It is possible that I won the greatest tennis tournament, Wimbledon, against perhaps the greatest tennis player of all time, Roger Federer – or at least I like to think it is! But what makes this possibility true? Less ambitious modal statements such as, ‘it is possible that I became a bus driver, or went to the shops, or got married’, seem to be possibilities that really do exist. But in virtue of what are they true? In this essay I will provide a theory of modality based on an ontology of powers.1 1 Truth-making When I say it is possible that I take a shower, we intuitively think, ‘Yes, that is possible.’ But then the difficult question arises, ‘In virtue of what is this possible?’ Some people might shrug their shoulders and say, it just is. But those of us philosophically minded will demand something more. We want to know what the truth-maker is of the proposition ‘It is possible that I have a shower’. David Armstrong summarises the basic truth-maker theory nicely when he writes: * Delivered at the BJUPS Spring Conference, 21–22 March 2015 at the University of Southampton. 1 For the most comprehensive account of a power-/disposition-based modality see: Vetter [41]. 36 Issue 9 (1) – Spring Conference 2015 The idea of a truth-maker for a particular truth, then, is just some existent, some portion of reality, in virtue of which that truth is true. . . . To demand truth-makers for particular truths is to accept a realist theory for these truths. There is something that exists in reality, independent of the proposition in question, which makes the truth true.2 This theory of truth will be assumed for the rest of the paper, as we search for the truth-maker of the possibility that I won Wimbledon. 2 Current Solutions Current theories of modality employ the use of possible world semantics. This means that when we say it is possible that I won Wimbledon; the thing that makes this true is that there is some possible world in which I win Wimbledon. In using the language of possible worlds we need to ascertain whether there are any ontological implications, or whether we should “regard that language as no more than a convenient façon de parler, or as merely a useful heuristic device”.3 There are two popular theories that provide an analysis of what possible worlds actually are. First is David Lewis’s modal realism.4 According to this view, there really exist possible worlds in which these possible scenarios play themselves out, which count as the truth-makers of modal statements. Lewis’s theory is categorised as possibilist since it involves possible entities’ existing in the same sense as actual ones. These other worlds exist, for Lewis, and in that sense are real, but the only world that is actual is the world in which we, the observer, find ourselves, with ‘actual’ functioning as an indexical, like ‘here’ and ‘now’. Alvin Plantinga, Robert Adams, and others, hold the second way possible worlds have usually been interpreted – an ersatzist5 or platonic approach.6 On this view “talk about possible world[s] [is] to talk about sets of propositions”, with a possible world perhaps being thought of as a worldstory, “a maximal consistent set[s] of propositions.”7 This view, in contrast 2 Armstrong [2] p. 116. 3 Lowe [22] p. 115. 4 Lewis [20]. 5 Meaning 6 Adams 7 Ibid. ‘replacement’ or ‘substitute’. [1] pp. 211–231. pp. 225. 37 British Journal of Undergraduate Philosophy with Lewis’s, is actualist since these propositions, or world-stories, are actually existing propositions within this world. The theory I will offer will be actualist in flavour but will not rely on abstract platonic propositions or linguistic entities to account for the truth-makers of modal statements. Instead it grounds modality within the ‘physical’ world. Barbara Vetter categorises these modal theorists as ‘hardcore actualists’, since “they do away entirely with the appeal to possible worlds”.8 Possible worlds, on this account, are seen as a mere heuristic device or façon de parler that can be used to illustrate modalities. There is more than one ‘hardcore actualist’ approach in the literature, with some grounding modality in essence,9 whilst others ground it in powers. It is the powers account that I wish to explicate and advocate in the remainder of this paper. 3 Powers Before explaining how powers ground modality, it will be important to understand what powers are. Powers, dispositions, capacities, tendencies10 have undergone somewhat of a revival within analytic metaphysics.11 Examples perhaps provide the easiest way to grasp what a power is. We say that I have the power to type on my keyboard, that my car has the power to drive at 30mph, that a hammer has the power to shatter a glass and that my front door key has the power to open my front door. Powers point beyond themselves towards their manifestations. Electrons are negatively charged entities, with negative charge repelling other things with negative charge. The negative charge of an electron, therefore, confers the electron with the power to repel other electrons. But more than this, the electron has the power to repel another electron even if it is never in a suitable environment to manifest this power. The power is not real only when the electron is actually repelling another electron, as the ancient Megarians thought, but rather is real even if it never manifests and repels another electron. We might say, as C. B. Martin 8 Vetter 9 See [40] p. 742. for example: Fine [12] pp. 1–16, Lowe [23] pp. 23–48. 10 These terms have generally been used interchangeably and so should be thought as synonymous, but I shall keep to the terminology of powers for the remainder of this paper. 11 See for example: Mumford [27], Molnar [26], Groff & Greco [13], Marmodoro [24], Jacobs [17]. 38 Issue 9 (1) – Spring Conference 2015 does, that powers are always in a ‘ready to go’ state.12 However, when a power meets its stimulus condition, or mutual manifestation partners, it manifests, with its effect occurring, such as one electron’s repelling another. One final thing to be noted is that the manifestation of a power is essential to the power itself. Thus the property negative charge is linked essentially with ‘will repel other things with negative charge’. This means that my account of modality is non-reductive, since there is a level of primitive modality: the essential link of a power to its manifestation. There is much more that could be said regarding the metaphysics of powers; nevertheless, this brief introduction will suffice for our purposes. 4 A Powerful Modality Supposing that there are powers, how might we ground modality? The basic idea is that objects around us possess certain powers, and these powers ground the possibility of things occurring. The principle could be stated as follows: A state of affairs S is possible iff there is some actual dispositional [powerful] property D, which supports a disposition [power] d, the manifestation of which is (or includes) S.13 What makes it the case that something is possible is that an object has a power which, if manifested, would result in that possibility’s being realised. An example will help explain this further. It is possible that I am unable to take my booked flight to Edinburgh to see my girlfriend because of the plane’s breaking down. What grounds this possibility is that one of the components of the plane has the power to break when overused or placed under increased stress, and it may be the case that this power comes into contact with its stimulus condition or mutual manifestation partner and therefore manifests, resulting in the plane breaking down and my flight being cancelled. Or to take another example, what makes it possible that salt dissolve in water is that it has the power to dissolve in water when met by an appropriate stimulus condition or mutual manifestation partner. When a mutual manifestation partner comes into contact with the salt, such as water, the salt will dissolve, but it may never meet this condition and thus never dissolve. Yet the possibility of the salt’s dissolving is grounded, not in another real possible world where it is dissolv- 12 Martin [25] p. 55. 13 Borghini & Williams [5] p. 28. 39 British Journal of Undergraduate Philosophy ing, nor an abstract platonic world-story, but rather in the powers that the salt possesses. How about the possibility that we started with – my winning Wimbledon – what makes this possible? This possibility is grounded in certain powers manifesting or perhaps not manifesting, which would have made it the case that I won Wimbledon. Such things would seem to include my playing the correct amount of tennis at certain times, my muscles’ being activated to grow in certain ways at certain times from the correct amount of training, my having good training partners, etc. Note that in this case, these powers would have had to have been chain-like and would have needed to start manifesting a very long time ago, requiring many different powers to manifest themselves in order for this possibility to be realised. It might also be the case that had some powers manifested then this realisation wouldn’t have occurred, such as my leg’s breaking due to increased stress. Therefore the possibility of my winning Wimbledon would require a very particular chain, precisely tuned, so that powers manifested or did not manifest at particular times. Equally, however, this chain of powers also almost grounds the heart-breaking possibility that I am denied winning Wimbledon, as in the final I receive an injury in the last game and cannot continue. This example is highly complex and to see how powers ground modality it is easier to start with examples which do not require such long chains into the past, with very many different manifestations happening or not happening at specific times. Nevertheless, once one appreciates how this account grounds more basic possibilities, such as ‘it is possible that this salt dissolve’, one should be able to see how this account would ground larger more complex possibilities. One way that may help us better understand this way of grounding possibility is through a branching tree. When a power manifests, it creates a new branch, where new possibilities emerge in virtue of that power’s manifesting at a certain time. So we could say that the power A not manifesting at time t 1 , means that X will happen, but if A does manifest at t 1 , then Y will happen. If X occurs, then at t 2 , if X manifests, Z will happen; but if X does not manifest, W will occur. If, on the other hand, A did manifest then Y happens at t 1 , meaning that at t 2 if Y manifests then B will occur, but if it doesn’t C will. The tree becomes more complex when we realise that A does not manifest in isolation, but rather many, many, many different things manifest at t 1 , or do not manifest at t 1 , resulting in the amount of possibilities that are realisable being very large. Adopting a theory such as this allows us to remove possible worlds from our ontology, grounding possibility purely in powers, and providing us with a ‘hardcore actualist’ ontology in which every metaphysical possibility is grounded in this world’s objects’ powers. Truth-makers to our 40 Issue 9 (1) – Spring Conference 2015 modal claims, therefore, are found in the powers of objects in the actual world. John Heil summarises this nicely writing, “Claims about possibility and necessity, modal claims, are made true by the dispositional [powerful] structure of the universe.”14 5 Why This Account? Having explicated a powerful modality, why would anyone adopt it rather than embrace the account of Lewis or Plantinga? In this section I will argue that the powers account should be favoured over these two suggestions. On Lewis’s account, the truth-maker of ‘possibly: I win Wimbledon’ is that there is a real world where I win Wimbledon, although, as it turns out, I don’t actually win Wimbledon. Lewis is well aware that I cannot be in the actual world, this one, and another real world, since that world would then also have to be actual for me, and I would be in two places at once. So who wins Wimbledon? For Lewis, it is my counterpart that wins Wimbledon, which somehow is the truth-maker of my possibly winning Wimbledon. My counterpart, for Lewis, would be something that is as similar to me as possible, and yet it is not me. So there are many different possible worlds on this account, some very similar to this actual world, and some very different. The truth-maker of my possibly winning Wimbledon is that in some similar world my counterpart does win Wimbledon. To make things easier to understand, we might liken what Lewis is saying to a scenario that might occur between identical twins. It just so happens that within the tennis world there is a pair of identical twin brothers that are the most successful doubles pair of all time: the Bryan brothers, Mike and Bob. Now Lewis’s account seems to me similar to this scenario. Mike and Bob decide they are going to compete for the Wimbledon singles title, Mike proceeds to lose in the first round, whilst Bob goes all the way and wins the title. When Mike asks Bob “Is it really possible that I could have won Wimbledon?”, Bob replies “Yes, my winning Wimbledon provides the truthmaker for your winning Wimbledon since we are pretty much the same.” I have a strong intuition that Mike would find this reply far from comforting. What it seems to come down to is saying that I can take comfort in the fact that someone extremely similar to me has won Wimbledon; but this doesn’t seem to provide a truth-maker for the statement ‘possibly: I win Wimbledon’, since I am not this similar person. 14 Heil [15]. 41 British Journal of Undergraduate Philosophy But things seem even worse when we think about my winning Wimbledon, or rather my counterpart’s winning Wimbledon. My counterpart is as similar to me as he can be in order to win Wimbledon, but perhaps that just isn’t very similar at all. Maybe in order for my counterpart to win Wimbledon the world has to radically change; perhaps everyone else who would beat me becomes injured at the same time and so my counterpart with my DNA actually wins since no one else is in a state to play. Or perhaps my DNA is such that I just am unable to win Wimbledon, and so the closest possible world that my counterpart wins Wimbledon, is one where my counterpart is born from different parents, or is bitten by a radioactive tennis ball (rather than a spider) so that my genetic makeup changes in order that I win the tournament. But even though this counterpart is the closest it can be to me whilst also winning Wimbledon, it doesn’t seem that it provides a truth-maker of its being possible that I won Wimbledon. I don’t win Wimbledon and it doesn’t look like it is possible that I could. This modal intuition of mine – against the counterpart theory – I take to be pretty strong and for this reason I am not convinced that Lewis’s account can provide truth-makers for modal truths such as ‘possibly: I win Wimbledon’. However, we have seen, although it would require a long and complex chain – or better, a web – of powers manifesting or not manifesting precisely at certain times throughout my life, and perhaps even before my life, that we can provide a truth-maker for this proposition rooted in the powers of things. Another reason for accepting my account over Lewis’s and the platonic approach is that it is more ontologically parsimonious. Rather than accepting, as Lewis does, that there are many other real worlds, or that there are platonic entities as the platonist account does, one need only postulate this world to account for the truth-makers of modal statements. Only things, ‘material’ things, are needed to account for the truth-makers of modal statements. David Peroutka puts it succinctly when he writes, “Something is possible if there are active and passive causal capabilities enabling its production.”15 Since this world is a world full of powers it can do the job itself of providing the truthmakers of modal statements. Perhaps you think there is little reason for accepting one theory of modality over the other. It therefore seems that we need other grounds in order to determine which account we should favour. I happen to think there are strong grounds to believe in an ontology that includes powers, but this paper is not 15 Peroutka [34] p. 204. 42 Issue 9 (1) – Spring Conference 2015 the place to present them. Instead I shall contend that one should accept an ontology of powers due to the different range of phenomena powers can help explain.16 For instance, powers have been used by some to help explain causality. For instance Stephen Mumford and Rani Anjum, in a book-length treatment ‘Getting Causes From Powers’ write, “This gives the simple essence of the dispositional [powerful] theory of causation. Effects are brought about by powersmanifesting themselves.”17 Heil agrees with this sentiment, arguing that “causings are typically mutual manifestings of many reciprocal powers”.18 Another area in which powers have proved useful is in explaining the ontology of laws of nature.19 George Molnar for instance writes, “Natural laws of a world have as their truthmakers the essential irreducible powers of the objects of that world.”20 Brian Ellis echoes this, claiming that “the truth-makers for the relevant laws of nature are, we hold, just the fundamental dispositional [powerful] properties”.21 Further, a theory of powers allows one to revive a theory of natural law in ethics. Anthony Lisska for instance writes, “Moral ‘properties’ are based upon dispositional [powerful] or developmental properties”, and later, “A disposition [power] has, as a part of its very nature a tendency toward a specific end. This end, when realised, contributes to the well-being of the individual.”22 Finally, Stephen Boulter has argued that a power-inspired theory of modality best explains the modality involved within evolutionary explanations.23 Since parsimony is seen as virtuous in ontology, and since powers seem to be able to do much work in our metaphysics, through flexing their powerful muscles, broader grounds should persuade us to adopt this view of modality. 16 Karen Bennett defends a similar approach to this. See Bennett [3]. 17 Mumford 18 Heil 19 I & Anjum [28] p. 7. [14] p. 120. discuss this elsewhere. See Page [33] pp. 114–122. 20 Molnar 21 Ellis [26] p. 162. [9] p. 128. 22 Lisska [21] p. 88, p. 107. 23 Boulter [6] pp. 116–132. 43 British Journal of Undergraduate Philosophy 6 Objections One objection to the account I have given is that powers are already modal and so cannot do the job I have supposed they can. That they are modal can be conceded, and so we should think of this account of modality as non-reductive, which shouldn’t be taken as problematic.24 A more serious objection could be given as follows. Consider the thought that this table might not have existed. This seems prima facie plausible, namely that the table is a contingent existent. What power of the table makes this claim true? It seems that the answer to this question is that certain powers would have to manifest in order that the table exist. But it is possible that they never manifested, and so it is possible that the table never existed. This seems an adequate response for a table, but things become more troublesome when we think of the world.25 When I think of this world I think that most things in it are contingent entities: things might have failed to exist, this world might have failed to exist. Power theorists can plausibly argue that laws of nature are necessary given the powers in the world.26 And one might accept this, but the laws of nature don’t seem necessary in that there couldn’t have been different powers instantiated. Neither does it seem that any of the powers should have existed at all. Since I have argued that what ground possibilities are powers that may or may not manifest, it seems we have contingencies all the way down. Thinking of this in terms of a tree, as I suggested above, we are asking what grounds the root from which we start. Some may claim that this is unproblematic, suggesting that this contingency is just a brute fact. Nevertheless, this may not satisfy us. In asking what powers were manifest in order for the world to exist, we might reply that contingency is merely apparent. The powers that start the whole process are just constantly manifesting, and so are necessary. It thus turns out that there are fewer contingencies than we think. Perhaps the particles of particle physics are necessary, and thus there just couldn’t have been any different fundamental particles. However, this results in a radically diminished modal landscape. The need to ground these contingencies in something necessary might cause us to seek another option.27 God, classically conceived, is what grounds all exis- 24 Jacobs 25 Pruss [16] p. 233. [38] pp. 216–217. 26 Oderberg 27 This [30] pp. 143–151. seems to be similar to the basis of Aquinas’s first way, see: Feser [10] pp. 65–81, Oderberg 44 Issue 9 (1) – Spring Conference 2015 tence through being pure actuality, or in our terminology pure powerfulness, and is therefore necessary.28 It can be argued that pure power cannot be anything physical, and therefore the suggestion above regarding physics may fail.29 Therefore, if we want to embrace pure power, something necessary, we should think of God, traditionally conceived, as the ground of these powers. This should not be seen as a postulation, but rather a conclusion based on the need for a pure power to ground all other contingencies. This results in a contingent world and allows for the possibility of other worlds with different powers. However, the problematic element of this suggestion is that we no longer rely on purely physical powers, but also on God, traditionally conceived as pure powerfulness. This problem seems linked to another, David Lewis’s so-called ‘alien properties’, these being “properties that nothing in this world shares”.30 If there are such things as alien properties, what makes them possible? On my account of modality it seems that we are stuck only with the properties or powers of this world. But this won’t be able to provide us with Lewis’s alien properties. One might argue that there are some things that we think are possible, which just aren’t. Perhaps we can alter Walter Ott’s advice regarding causation to answer Lewis. Malebranche and Hume find no difficulty whatever in conceiving of alternative courses of nature; any sublunary event might be followed by any other. It is open to their opponents to argue that they have either misdescribed what they are conceiving or failed to conceive anything at all.31 Lewis might think that he can conceive of alien properties but he cannot do so at all. It is the nature of actual powers that determine what there could be, and therefore we can just reject that there are such things as these possible alien properties. This response seems a little heavy handed, and it would be beneficial if we could accommodate alien properties in our account of possibility since there do appear to be some strong examples of alien properties. One might be that there appears to be a gap within the periodic table, element 113 [31]. 28 Davies [7] pp. 2–9. 29 Oderberg 30 Lewis 31 Ott [30] pp. 138–143. [20] p. 1. [32] p. 248. 45 British Journal of Undergraduate Philosophy (ununtrium), whose empirical discovery, at this time of writing, still awaits confirmation. If we suppose it never gets confirmed or created, it still looks like a possible property and yet it would have to be considered an alien property. Another property might be one that makes gravitational forces weaken less rapidly as the distance between masses becomes greater than they actually do. What other ways could we account for such properties? The Scholastics, who in the Middle Ages systematised a power ontology,32 distinguished between two types of powers, or potencies.33 Subjective potencies “are grounded in a real subject, rather than merely existing in an object of thought”,34 and objective potencies are merely possible existents, but as merely possible entities do not exist in the actual world.35 So far we have talked more of subjective potencies rather than objective ones. An objective potency, such as a unicorn existing, is really a possible existent, since it contains no contradiction, but nevertheless does not actually exist. It seems we could say that there are actual powers in this world, subjective potencies, which if activated in a chain-like fashion would result in a unicorn. Thus, if we mean by ‘alien properties’ things such as unicorns, then this account can ground the possibilities of these existents. But there are other properties which are alien, in the sense of non-existent in this world, that cannot be accounted for by merely the powers in this world and I suspect that it is these properties that Lewis’s alien problem is directly concerned with. The problem, in scholastic language, is that the subjective potencies, grounded in things in this actual world, cannot account for all the objective potencies, merely possible entities. Recombinations of this world’s powers may provide us with some objective potencies, but by no means all of them. Put this way, how one answers the previous difficulty, the contingency of this world, will determine what one may be able to say in response to Lewis. If one adopted a brute fact approach to the previous objection, then perhaps one can reply to Lewis that there may be other brute facts which would ground the possibility of alien properties. The problem with the suggestion is that it seems to remove the ‘hardcore actualist’ nature of the account, since presumably these brute facts are not physical. Further, as I noted above, the brute fact 32 Kenny [18] p. 66. 33 Phillips 34 Feser [35] pp. 182–183, Bittle [4] pp. 60–61. [11] p. 39. 35 Runggaldier [39] p. 188. 46 Issue 9 (1) – Spring Conference 2015 approach does not seem to be a particularly robust answer and so we should try to avoid it. If we adopted the view that the fundamental particles are necessary, as they are always manifesting, then we must take the hard line to Lewis’s question, as spelled out above, that there are no – or only a limited number of – alien properties. A different answer, not suggested previously, would be to become a modal realist like Lewis and make a commitment to the existence of possible worlds which are causally or nomologically unlike this world, the actual one, in which these alien properties exist. This again loses one the status of ‘hardcore actualism’, but seems to solve the problem. The only other way we seem able to ground these types of properties is by embracing a being that is pure powerfulness: God traditionally conceived. Jonathan Jacobs suggests this writing: On this view God could bring it about that any number of actually uninstantiated properties are instantiated. The plenitude of possibility would then be grounded in the powers of actually existing objects, including the power of an omnipotent God, to bring about various instantiations of properties, including alien properties.36 A being that is pure powerfulness can instantiate any objective potency when realising the universe, since its power is not limited by anything, including matter. The realised subjective potencies then determine the natural possibilities of the world, and thus powers provide the truth-makers of our worldly modal statements.37 The problematic element of this suggestion is once more that physical powers are not doing all the modal work: God is now also involved. Some will no doubt baulk at this suggestion in which case they may adopt a brute fact or restrictedly modal world. However, it should be remembered that we drew God as a conclusion, due to needing something purely powerful to ground contingent powers, and this is what God, traditionally thought of, is. With some current power theorists also arguing that God is required to ground a robust modality, I do not feel lonely in offering this suggestion.38 36 Jacobs 37 For [16] p. 238. a similar account see: Dvořák [8] pp. 72–83, Pruss [37] and [38]. 38 Pruss [37] and [38], Leftow [19], O’Connor [29], Jacobs [16]. 47 British Journal of Undergraduate Philosophy Conclusion Powers, then, provide a powerful ‘hardcore actualist’ theory for the truthmakers of modal claims, and do not commit us to postulating other entities to do the job, such as other non-actual worlds, or non-spatiotemporal platonic entities. I have suggested some responses that a power theorist might make when countering objections to this view, advocating that the combined theist and power account answers the objections most thoroughly whilst also providing some suggested responses for non-theists. Given all this I take it that powers are able to provide us with a powerful theory of modality.39 References [1] Adams, R. M. 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