Identity Matters: Foetuses, Gametes, and Futures like Ours

Abstract Recently, a number of philosophers have argued that, despite appearances, the success of Don Marquis's well-known future-like-ours argument against abortion does not turn, in an important way, on the metaphysics of identity. I argue that this is false. The success of Marquis's argument turns on precisely two issues: first, whether it is prima facie seriously wrong to deprive something of a future like ours; second, whether, in a counterfactual circumstance in which an abortion does not occur, the foetus is numerically identical with something that, later on, experiences a life like ours. Since the former claim is plausible (albeit disputable), the success of Marquis's argument does turn on the metaphysics of identity in an important way. Before defending a positive argument for this position, I consider what I take to be the most promising way of challenging it. This involves a recent objection to Marquis by Tim Burkhardt (2021). Burkhardt claims that his objection floats free of the metaphysics of identity. I argue that it fails to do so, and that in fact it fails outright. I end by considering the relationship between my arguments and the question of what matters in survival.