Mark Moyer's Dissertation

For the non-philosopher, material objects are entirely unproblematic: beyond the ken of common sense there is certainly a mysterious realm of science, but this is merely a realm of things too small to see or feel. According to the metaphysician, however, material objects present deep puzzles that call into question the beliefs that, one might think, are constantly confirmed through direct perception. With our first steps into metaphysics we learn a single overarching moral: "We will have to say something counter-intuitive, but we get a choice of evils." The statue on the mantle does not exist! Only part of the statue is currently upon the mantle! Multiple objects sit upon the mantle exactly where the statue sits! Such are the revelations of metaphysicians. In A Semantic Approach to Material Constitution, I attempt to dissolve some of these puzzles, i.e., to show that we need not contradict common sense after all. This dissertation consists of a short introduction and four chapters. One common thread tying together the four chapters is the claim that once we properly distinguish temporary and contingent identity, relations holding only at a time or world, from absolute identity, various puzzles dissolve of their own. Several philosophers before have drawn this distinction, though I show how this one equivocation underlies several different metaphysical mysteries. A second common thread that weaves together the four chapters is the free use of what has been called 'the semantic approach'. Many of the disputes within material constitution take place against a background of an agreed upon supervenience base. Given a particular arrangement of matter, one philosopher claims there is both a statue and a lump of clay, another says there is only a statue, and a third denies that even the statue exists. But where is the truth-maker that can distinguish such positions? Since the idea of an unobservable 'metaphysical extra' seems rather dubious, one natural place to look is with our language. I apply semantic, or conceptual, analyses to argue that such disputes do indeed ride on semantic facts. Thus, the dissertation brings together arguments of a style typical of metaphysics with arguments and a methodology that draw upon traditional philosophy of language. In this way, the arguments I offer may be seen as part of a larger project of coming to understand the extent to which, and the ways in which, philosophical disputes seemingly about the structure of the world can turn out to be disguised problems about the structure of our language or thought. The first chapter addresses the question of whether material objects can coincide. Because the statue and the lump of clay, for example, have different temporal and modal properties, Leibniz's Law dictates they are distinct. But common sense tells us that there is only one thing on the mantle, that two things can't occupy the same place at the same time, that the weight of two objects is the sum of their individual weights, and so forth. These and similar reasons for denying coincidence have been supported by Burke, Doepke, Heller, Lewis, Myro, Rea, Sider, Wiggins, and Zimmerman. I argue that the distinction between temporary and absolute identity, if consistently applied, preserves common sense and yet shows that, in an important sense, multiple things do coincide. Burke and Heller also offer another sort of argument against coincidence, now quite popular. They claim that the statue and the lump of clay could not be distinct, for there would then be no explanation of their differences in sort. Both arguments fail, giving rise to a positive account of what explains an object's sort, viz. its temporal and modal properties. The second chapter compares two varieties of temporal parts theory, 'Worm Theory,' which claims that objects are time worms, and 'Slice Theory', which says that objects are momentary time slices. Taking a cue from Lewis's modal counterpart theory, Slice Theory adopts a temporal counterpart theory. That is, Slice Theory evaluates temporal predications using counterpart relations that span times. I offer a criticism of Slice Theory which shows that the account needs a modification: we do not refer to the current slice, as Slice Theorists aver, but to the slice causally responsible for our knowledge of the object, a position motivated by theories of reference. Slice Theorists have conceded various costs to their account, but I argue that they use temporal predicates like 'persists' ambiguously. Once we distinguish English from the homonymous technical terms of the theory, their concessions are unnecessary. As a result, Slice Theory matches Worm Theory truth condition for truth condition, differing only in what they call 'the referent'. Is this then a case of indeterminacy of reference, as Quine would have it? I say no. By preserving common sense through the use of a temporal counterpart theory, Slice Theory sows the seeds of the denial of its own claim to a radical metaphysic of momentary objects. The arguments of the second chapter are extended in the third chapter to address the modal counterpart theory Lewis endorses. Do objects span worlds or, as Lewis would have it, are objects instead world-bound, with counterpart relations underwriting the semantics of modal statements? First, we might consider a trans-world theory according to which objects span worlds by having parts at different worlds. Pace Lewis, such a theory is not equivalent to counterpart theory. To generate equivalent semantics, a trans-world theory would have to postulate more worlds than a corresponding counterpart theory. More importantly, the trans-world theorist would have to appeal to non-qualitative determinants of cross-world identity. Thus, the modal realist has two good reasons to reject trans-world theory. For the ersatzer, however, these objections do not apply, and, in fact, an investigation of the semantics shows that counterpart theory and trans-world theory generate exactly the same truth conditions for all modal statements. However, what conclusions we draw depends upon what is meant by a 'possible world'. Given one natural understanding, objects do exist at multiple worlds and, ipso facto, counterpart theory is wrong. Given another natural understanding, it is indeterminate whether objects span worlds, and on this understanding counterpart theory and trans-world theory are simply notational variants. Finally, in the fourth chapter I examine 'the paradox of fission'. If Adam undergoes fission, and we call the products of that fission Cain and Abel, who is identical to whom? Common sense says that Adam does not die at the time of fission, that he somehow lives on through Abel and Cain. Yet common sense also tells us that Abel is not the same person as Cain. It would be arbitrary to say that Adam is identical to only one of Abel or Cain, so it seems common sense commits us to the denial of the transitivity of identity. Lewis has offered one way to escape these consequences: 'Adam' is ambiguous, referring to one of two coincident people. Yet this ambiguity is itself contrary to common sense. Lewis applies enough semantics to argue that it is correct to say that there is only one person present before the fission. Merely by pursuing the same distinction of temporary and absolute identity, I argue that 'Adam' refers to one person and that the name is not ambiguous. The result is that 'Abel' refers to one time worm, 'Cain' refers to a partially overlapping time worm, and 'Adam' refers to a two-headed, or Y-shaped worm that includes both of the previous worms. It may seem that this result is even more jarring to common sense than the ambiguity Lewis posits, but this perception rides on a conflation of temporary and absolute identity. The semantics, once spelled out, generate no claims that conflict with intuition.