Derek Parfit’s argument against the platitude that identity is what matters in survival does not work given his intended reading of the platitude, namely, that what matters in survival to some future time is being identical with someone who is alive at that time. I develop Parfit’s argument so that it works against the platitude on this intended reading.

Derek Parfit has offered numerous arguments in an attempt to establish that identity is not what matters. Jens Johannson has recently argued that Parfit's various arguments for the claim that identity is not what matters fail to establish what Parfit takes such arguments to establish. Johannson contends that this is due in part to the invalidity of one of Parfit's key arguments, and the fact that Parfit ignores a position that is compatible with the conclusions of his successful arguments and (...) the claim that identity is in fact what matters, namely, that I survive fission as either one of the fission products or the other, but it is indeterminate which one I survive as. I aim to establish here that both of Johannson's assertions are problematic. As a corollary of this task, I hope to shed some light on the relationship between indeterminacy and fission-based arguments for the claim that identity is not what matters. (shrink)