A certain artist, whom we may call “Art Garfinkel”, often visits so-called junkyards, in search of such scraps of metal as will not just catch his eye, but, more than that, which will hold his attention quite enjoyably. On one of these visits, as it happens, he finds most appealing a certain junky piece of copper, shaped just like a lump, and nothing like, say, a disk. Purchasing the piece for just a pittance, and naming his acquisition “Peter Copperfield,” Art has it in mind to use this newly named Peter in a certain moderately complex artistic endeavor, a brief description of which I now provide.

Covering Copperfield with a suitable sort of wax, Garfinkel first uses the purchased piece to make a suitably shaped mold, the mold being made not of copper, of course, but of some quite different material, very well suited for making a mold of just the sort Art knowledgeably aims to produce. What the mold will be used for, once completed, is to make a sculpture, from molten copper. For Garfinkel, the point of that is this: After that copper hardens, he will have produced, in that way, a sculpture that, at least in all intrinsic regards and respects, is very like Peter Copperfield, the purchased piece of coppery junk. Using this mold, Art pours into it (at least very nearly) exactly as much (molten) copper—at least down to the nearest one thousandth of a milligram—as is contained in Copperfield. That copper hardens so as to form a piece of copper, one that’s always spatially distant from, and that’s ever so separate from, the purchased Copperfield. This newly hard piece of copper, it may be noted, contains no matter that ever served to compose the piece bought in the junkyard, Peter Copperfield. Amusingly, Garfinkel names the piece of copper he intentionally produced “Peter Copyfield”.

Having studied philosophy when in college, AG was quite uncertain that any piece of copper could ever be a copper sculpture; indeed, he was inclined to think not. In any case, he gave another name, “Untitled #42”, to the sculpture he produced exactly when and where he produced Peter Copyfield. So it was that, entirely made of copper, there came to be Untitled #42, an artwork that, fairly rocking even the coolest of the cognoscenti, brought AG a cool $6,000,000, with an equal amount going, of course, to his very fashionable dealer.

With that said, we’re almost done with our little story. The rest is just this: After resting in a billionaire’s penthouse for a while, perhaps about a month, the matter composing Untitled #42—matter also composing Peter Copyfield—is annihilated. In a moderately realistic case of that, the matter may be nuked. Perhaps better for our consideration, though not a great deal better, is a case where the matter is converted to energy. In this latter case, even the matter itself suddenly ceases to be.

In the story just told, a certain piece of copper and a certain copper sculpture are, from the first moment of their existence until their very last, always spatially perfectly coincident. And, throughout their history, each is composed of the same (copper) matter as the other. Still and all, it may well be that there are, indeed, those two distinct things I mentioned, Peter Copyfield being one of them, and Untitled #42 being the other notable thing. Just so, there will be only some quite confused thinking on the part of anyone who may think that, in our little story, we mentioned just one most salient cuprous thing, mentioning twice over just a single salient cuprous thing—with our sometimes using one of its names, “Peter Copyfield” and, with our using, at other times, another of its names, “Untitled #42”. As the chapter progresses, how confused that is will become very clear.

Toward beginning to make that clearer, we may ask about what could have been done to Untitled #42 with the result that it should then continue to exist, and also what could have been done to it with the opposite result, with the result that it should then cease to exist. Additionally, we may ask parallel questions concerning Peter Copyfield. In philosophically favored terminology, when asking those questions, what we’re asking is this: What are the persistence conditions of Untitled #42, the expensive copper sculpture? And, of about equal interest, what are the persistence conditions of Peter Copyfield, the piece of copper composed of just the very same copper that, throughout all the very same period of time, also serves to compose the pricey copper sculpture, Untitled #42?”

Peter Unger, Empty Ideas: A Critique of Analytic Philosophy, New York, 2014, pp. 110-112