Time and Identity

5 Identity through Change and Substitutivity Salva Veritate

Introduction This chapter has three modest aims: to present a puzzle, to show why some obvious solutions aren’t really “easy outs,” and to introduce our own solution. The puzzle is this. When it was small and had waterlogged streets, Toronto carried the moniker ‘Muddy York’. Later, the streets were drained, it grew, and Muddy York officially changed its name to ‘Toronto’. Given this, each premise in the following argument seems true. Yet the conclusion is a contradiction. (P1) Muddy York = Toronto (P2) Muddy York evolved into Toronto. (P3) The context ‘__ evolved into Toronto’ is transparent, that is, it allows substitution of coreferring singular terms. (P4) It’s not the case that Toronto evolved into Toronto. (C1) Toronto evolved into Toronto (by P1, P2, and P3). (C2) Toronto both did and did not evolve into Toronto (by P4 and C1). Of course the puzzle isn’t about Toronto. It’s not even about cities: the same conundrum arises with names of people (think of the well-known case of ‘Cassius Clay’ and ‘Mohammed Ali’), diseases (‘coronovirus’ and ‘SARS’), and so on. Nor is the puzzle just about “evolving into”: it can be generated with ‘changed into’, ‘turned into’, ‘became’, and so forth. Generalizing , an instance of the puzzle can be got whenever we have both accidental change—that is, qualitative change that preserves numerical identity—together with a change in name. 5 Identity through Change and Substitutivity Salva Veritate Reinaldo Elugardo and Robert J. Stainton 114 R. Elugardo and R. J. Stainton Before moving forward, two caveats are in order. We approach the puzzle as philosophers of language, not as metaphysicians; and our proposed solution to it is linguistic. No doubt the puzzle, being about change, time, identity, and the like, also raises metaphysical questions galore; but we take our linguistic points to be compatible with any remotely plausible metaphysical account of these.1 Related to this, we do not put forward our solution as definitive. We think it’s superior to the “easy outs” that we reject, but it’s not without its problems. In particular, it does leave us with one nonobvious metaphysical commitment. Four “Easy Outs” We now consider four natural reactions to the puzzle.2 Each corresponds to the rejection of a premise in the argument above. All four “outs” are initially attractive. We will try to show, however, that in each case the supposed “easy out” either requires biting a hard philosophical bullet or suffers from obvious empirical faults. Start with (P1) and (P2), since they can be dealt with quickly. Giving up (P1) avoids the substitution of ‘Toronto’ for ‘Muddy York’ at (C1). But to deny that Muddy York is, that is, is numerically identical to, Toronto, apparently involves giving up the identity over time of the one city. That’s a very significant cost, to say the least. It means, for example, that the city’s residents didn’t truly celebrate Toronto’s bicentennial in 1993, since no one thing has lasted that long. One might say: Cities are such fluid social creations that this isn’t such a cost after all. But remember: the puzzle generalizes. We mentioned people (and diseases). Thus, rejecting (P1) means, for instance, that one can’t really punish the very person who did the crime, after a name change, but only some other person who stands in the right causal-historical relation to the renamed evil-doer. We could equally have given examples of land-masses, species, etc. It seems, then, that for any changing object that has different labels at different times, we’d have to abandon identity. Of course some philosophers might be tempted to give up genuine identity over time. But this just is bullet-biting , and we think that can be avoided. Giving up (P2) doesn’t look any more promising. It seems a matter of historical fact: Muddy York evolved into Toronto. (You can look it up, if you don’t believe us.) You might object that given (P4) and (P1), we simply have to reject (P2). But again, that’s another bullet: this move lets metaphysical scruples trump seemingly obvious empirical observations. We hope to show that all such moves can be avoided. Identity through Change and Substitutivity 115 Abandoning (P3) seems a far more attractive option. In fact, when we first noticed the puzzle we thought we had found a new kind of opacity...