Material Constitution

Material Constitution

Ordinary objects are constituted by, or made up out of, aggregates of matter. A gold ring is constituted by a certain piece of gold. Clay statues are constituted by pieces of clay. We are naturally inclined to regard the statue and the piece of clay as being one and the same object, an object that simply belongs to multiple kinds (statue and piece of clay).
The puzzles of material constitution put pressure on this natural inclination. Here is one such puzzle. Let ‘Athena’ name a certain clay statue and let ‘Piece’ name the piece of clay that constitutes it. What is puzzling is that all of the following seem true:

(MC1)Athena exists and Piece exists.
(MC2)If Athena exists and Piece exists, then Athena = Piece.
(MC3)Athena has different properties from Piece.
(MC4)If Athena has different properties from Piece, then Athena ≠ Piece.

The motivation behind MC2 is that Athena seemingly has exactly the same location and exactly the same parts as Piece. So ‘Athena’ and ‘Piece’ are plausibly just different names for the same thing. The motivation behind MC3 is that Piece and Athena seem to have different modal properties: Piece is able to survive being flattened and Athena isn’t. MC4 follows from the Principle of the Indiscernibility of Identicals (a.k.a. Leibniz’s Law): ∀x∀y(x=y → ∀P(Px iff Py)). In other words, if x and y are identical, then they had better have all the same properties. After all, if they are identical, then there is only one thing there to have or lack any given property.[21]
The puzzles are sometimes taken to motivate eliminativism, since eliminativists can simply deny MC1: there are no statues (and perhaps no pieces of clay either).[22]
More often, however, the puzzles are taken to motivate constitutional pluralism, the thesis that ordinary objects are typically, if not always, distinct from the aggregates of matter that constitute them. (‘Typically’ because, in rare cases in which the ordinary object and the aggregate come into existence at the same time and cease to exist at the same time, some pluralists will take the ordinary object to be identical to the aggregate.) Pluralists reject MC2: clay statues are not identical to the pieces of clay that constitute them. Pluralists may deny that having the same parts at a given time suffices for identity, or they may instead deny that the statue and the piece of clay have all of the same parts.[23]
One of the main problems facing the pluralist solution is the grounding problem: the modal differences between Athena and Piece (e.g., that the one but not the other can survive being flattened) seem to stand in need of explanation and yet there seems to be no further difference between them that is poised to explain, or ground, these differences.[24]
Defenders of the pluralist response to these puzzles may, by similar reasoning, be led to accept that, in special cases, two objects of the same kind can coincide. Suppose, for instance, that we have a fantastically big net (Thin) with very thin netting. We then roll it up into a long rope, and we weave that rope into a smaller net (Thick) with a thicker weave. Since the nets intuitively have different modal properties—Thin, but not Thick, can survive the unraveling of the thicker net—the same sort of reasoning that leads one to reject MC2 underwrites an argument that the nets are not identical. In other words, there are two exactly colocated objects, both of which are nets.[25]
Constitutional monists, according to whom Athena is identical to Piece, will deny MC3. There are various ways of developing the monist response. First, one might insist that both Athena and Piece (which, on this view, are identical) can survive flattening: upon flattening, Athena ceases to be a statue, but does not cease to exist. We can call those who opt for this approach ‘phasalists’, since they take being a statue to be a temporary phase that Piece (i.e., Athena) is passing through.[26]
Alternatively, monists might deny that Piece (i.e., Athena) can survive being flattened. When Piece is flattened, Piece ceases to exist, at which point an entirely new piece of clay (composed of the same atoms) comes into existence. This strategy is sometimes called “the doctrine of dominant kinds”, since the idea is that when an object belongs to multiple kinds, the object has the persistence conditions associated with whichever of the kinds “dominates” the others. Because statue dominates piece, Piece is a statue essentially, and therefore cannot survive ceasing to be statue-shaped.[27]
Finally, monists might agree that Piece is able to survive being flattened and that Athena is not able to survive being flattened, and yet deny that Athena and Piece have different modal properties. How can that be? On one version of this approach (often associated with counterpart theory), the idea is that ‘is able to survive being flattened’ is context-sensitive, expressing one property when affixed to ‘Athena’ and another when affixed to ‘Piece’. On another, the idea is that ‘is able to survive being flattened’ does not express a property at all. Either way, we do not end up with any one property that Piece has but Athena lacks.[28]

2.4 Indeterminate Identity

A wooden ship is constructed and christened ‘Theseus II’. As planks come loose over the years, they are discarded and replaced. After three hundred years, the last of the original planks is replaced. Call the resulting ship ‘the mended ship’. The descendants of the original owners have been collecting the discarded original planks, and—three hundred years after the christening—they obtain the last of them and construct a ship that is indistinguishable from the original. Call the resulting ship ‘the reconstructed ship’. Which, if either, of these two ships is identical to Theseus II? It is natural to suppose that there is no fact of the matter: it is indeterminate which of the two ships is Theseus II.
However, there arguably can never be indeterminate cases of identity:

(ST1)Suppose that it is indeterminate whether Theseus II = the mended ship.
(ST2)If so, then Theseus II has the property of being indeterminately identical to the mended ship.
(ST3)The mended ship does not have the property of being indeterminately identical to the mended ship.
(ST4)If Theseus II has this property and the mended ship lacks this property, then Theseus II ≠ the mended ship.
(ST5)If Theseus II ≠ the mended ship, then it isn’t indeterminate whether Theseus II = the mended ship.
(ST6)So (by reductio), it isn’t indeterminate whether Theseus II = the mended ship.

ST2 relies on two seemingly trivial inferences: (a) from its being indeterminate whether Theseus II is identical to the mended ship to Theseus II’s being indeterminately identical to the mended ship and (b) from there to Theseus II’s having the property of being indeterminately identical to the mended ship. ST3 seems trivial as well: the mended ship is definitely self-identical, so it does not itself have this property. ST4 looks to be an immediate consequence of Leibniz’s Law: if Theseus II and the mended ship differ with respect to even one property, then they are distinct. ST5 is trivial: if they’re not identical, then it isn’t indeterminate whether they are identical.[29]
Eliminativists may go on to argue from ST6 to the conclusion that there are no ships, as follows. If indeed it isn’t indeterminate whether Theseus II is the mended ship, then there would seem to be five options:

(i)Theseus II is identical only to the mended ship.
(ii)Theseus II is identical only to the reconstructed ship.
(iii)Theseus II is identical both to the mended ship and to the reconstructed ship.
(iv)Theseus II is neither ship; it has ceased to exist.
(v)Theseus II never existed in the first place; there are no ships.

Options (i) and (ii) seem intolerably arbitrary, since the mended ship and reconstructed ship seem to have equal claim to being Theseus II. Option (iii) is out as well. If Theseus II is identical to both ships, then (by the transitivity of identity) they must be identical to one another; but they cannot be identical because they have different properties (e.g., the one but not the other is composed of the original planks). Option (iv) is problematic as well. The history of maintenance by itself would have sufficed for the persistence of Theseus II; the preservation and reassembly of the original parts by itself would likewise have sufficed for the persistence of Theseus II; and here we have managed to secure both. As Parfit (1971: 5) would say, “How could a double success be a failure?” Thus, we get (v) from argument by elimination. Fitting.[30]
Some respond to the argument by maintaining that it is indeterminate which of various objects ‘Theseus II’ picks out. If that’s right, then ST2 is arguably false. One cannot infer the existence of an individual who is indeterminately identical to Sue from the fact that it is indeterminate whether Sue (or rather Morgan) is Harry’s best friend. Analogously, one cannot infer the existence of an individual that is indeterminately identical to the mended ship from the fact that it is indeterminate whether Theseus II is the mended ship.[31]
The prima facie problem with this response is that there do not seem to be multiple objects such that it’s indeterminate which one ‘Theseus II’ picks out. After all, when ‘Theseus II’ was first introduced, there was only one ship around to receive the name! One can address this problem by maintaining that, despite appearances, two ships were present at the christening: one that would later be composed of entirely different planks and another that would later be reassembled from a pile of discarded planks. What is indeterminate is which of these two temporarily colocated ships was christened ‘Theseus II’.[32]
Other responses are available. One might reject ST1 on the grounds that the object christened ‘Theseus II’ ceases to exist as soon as the first plank is discarded, either because ships have all of their parts essentially, or because the ship that existed at the time of the christening is not identical to any ship that exists at any earlier or later time. One might deny ST2 on the grounds that there is no such property as the property of being indeterminately identical to Theseus II. One might deny ST3, affirming that the mended ship is indeterminately identical to the mended ship. Or one might deny ST4 by denying that the distinctness of Theseus II and the mended ship can be inferred from the fact that they do not share the indicated property.[33]

2.5 Arbitrariness Arguments

Arguments from arbitrariness turn on the observation that there would seem to be no ontologically significant difference between certain ordinary and extraordinary objects, that is, no difference between them that can account for why there would be things of the one kind but not the other. Here is an example (drawn from Hawthorne 2006: vii):

(AR1)There are islands.
(AR2)There is no ontologically significant difference between islands and incars.
(AR3)If there is no ontologically significant difference between islands and incars, then: if there are islands then there are incars.
(AR4)So, there are incars.

The idea behind AR2 is that islands and incars (see §1.3) would seem to be objects of broadly the same sort, namely, objects that go out of existence simply by virtue of changing their orientation with respect to some other thing (the water level in the one case, the garage in the other), without their constitutive matter undergoing any intrinsic change. The idea behind AR3 is that, if there truly are islands but no incars, then this is something that would seem to stand in need of explanation: there would have to be something in virtue of which it’s the case. To think otherwise would be to take the facts about what exists to be arbitrary in a way that they plausibly are not.
Similar arguments may be used to establish the existence of leg complements (on the grounds that there’s no ontologically significant difference between them and legs) and trout-turkeys (on the grounds that there’s no ontologically significant difference between them and scattered objects like solar systems).[34]
Eliminativists may of course resist the argument by denying AR1.[35]
The argument may also be resisted by denying AR2 and identifying some ontologically significant difference between islands and incars. For instance, a certain sort of anti-realist will say that which objects there are is largely determined by which objects we take there to be. Accordingly, the very fact that we take there to be islands but not incars marks an ontologically significant difference between them. Alternatively, one may attempt to identify an ontologically significant difference between the ordinary and extraordinary objects without endorsing anti-realism. In the case at hand, one might resist AR2 by insisting that islands have importantly different persistence conditions from incars. Incars are meant to cease to exist when their matter ceases to be inside a garage. But islands, contra hypothesis, do not cease to exist when they are completely submerged; they merely cease to be islands.[36]
How about AR3? Part of why it seems arbitrary to countenance islands but not incars is that one would seem to be privileging islands over incars by virtue of taking them to exist. For this reason, proponents of certain deflationary ontological views are well positioned to deny AR3. Relativists, for instance, may maintain that islands exist and incars do not exist—relative to our conceptual scheme, that is. Relative to other possible schemes, incars exist and islands do not. Quantifier variantists, who maintain that there are counterparts of our quantifiers that are on a par with ours and that range over things that do not exist—but rather exist*—may maintain that islands exist but do not exist* while incars exist* but do not exist. On such views, islands and incars receive a uniform treatment at bottom; islands are not getting any sort of “special treatment” that cries out for explanation.[37]

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Material Constitution