Philosophy 2 Discussion Board

● The problem of material constitution is that the following assumptions are all plausible, but together lead to a contradiction The Existence Assumption (i) there is an F and there are ps that compose it The Essentialist Assumption (ii) if the ps compose an F, then they compose an object that is essentially such that it bears a certain relation R to its parts The Principle of Alternative Compositional Possibilities (PACP) (iii) if the ps compose an F, then they compose an object that can exist and not bear R to its parts The Identity Assumption (iv) if the ps compose both a and b, then a is identical with b The Necessity Assumption (v) if a is identical with b then a is necessarily identical with b ● Rea observes that none of the three puzzles he has considered so far—the Growing Argument, the Ship of Theseus and the Body-minus Argument—presents a problem to the “four-dimensionalist” A four-dimensionalist is someone who believes that ordinary material objects persist, that is, exist through time, by perduring A thing perdures if it is partially present at any given moment; a thing endures if it is wholly present at each moment it exists So a four-dimensionalist, aka a perdurantist, thinks that material objects are spread out in time in the way that everyone thinks that material objects are spread out in space A material object is a space-time worm, then, with only a temporal part present at each moment The whole material object is the thing from the beginning of its existence to its end ● None of the puzzles considered so far raises a problem for the four-dimensionalist because in each case they can deny that the ps at t compose a cat or a ship or a human person a material object, like a cat, is not composed of any ps at one time—that cat is composed of a bunch of ps at many times so Tib (or Body-minus) in the Tibbles case is just a proper part of Tibbles the cat Tib is never identical to Tibbles

likewise, a body is never identical to a human person, it just sometimes has an exactly overlapping part just like my nail can be a part of my finger and my hand, Tib at a moment, that one thing, can be a part of Body and part of Tibbles, which are distinct similar things can be said in the case of the human person/body in the Growing Argument and the continuously repaired/reassembled ship in the Ship of Theseus ● Does this show that there is no problem of material constitution, then? If one just accepts four- dimensionalism, all the puzzles seem to be resolved Well, this is not correct, for a similar puzzle arises even for the four-dimensionalist, the puzzle of Lumpl and Goliath, the ancient problem of the Statue and the Clay “A sculptor sets out to create a statue of the infant Goliath, but he does so in the following way: he sculpts Goliath’s upper body from one piece of clay, his lower body from another, and then finishes the statue by sticking the two pieces of clay together. Thus, in joining the two pieces of clay he simultaneously brings into existence a new piece of clay and a completed statue of the infant Goliath. He allows the clay to harden, but then a day later (perhaps dissatisfied with his work) he smashes the statue, thereby terminating the careers of both the statue and the piece of clay. The question is whether the statue in this story (Goliath) is identical with the piece of clay (Lumpl)” (Rea, 543) ● This is yet another version of the problem of material constitution, so the five assumptions above are operative and lead to a contradiction —The argument involves an Existence Assumption, there is a statue composed of particles —It involves an Essentialist Assumption, namely, where this statue is is a lump of clay composed of particles where a lump is such that it must be made up of just the things that compose it, that very lump, Lumpl, could not have been made up of other particles in other words, there is an object such that, necessarily, for all qs and t, the qs compose z at t only if z bears R3 to the qs, where R3 is defined as follows: z bears R3 to the qs =DF the qs are the ps —the (PACP) is made, for one assumes the ps compose a statue, something that could have been made up of different parts, that is, the ps compose something that does not bear R3 to the things that compose it —The Identity Assumption is made; thus, one assumes that the statue is identical to the lump

—The Necessity Assumption is made, otherwise one could assume that the statue could be identical to different lumps in other possible scenarios (and, hence, different things in different scenarios) ● Rea notes there is actually a second puzzle here: Goliath could not survive being squashed, but Lumpl could This version is captured with a different Essentialist Assumption, namely, where this thing is is a statue composed of particles where a statue is such that it must be made up of ps arranged in a certain way in other words, there is an object such that, necessarily, for all qs and t, the qs compose z at t only if z bears R4 to the qs, where R4 is defined as follows: z bears R4 to the qs =DF the qs compose a statue