The significance of personal identity to abortion.

In ‘The Insignificance of Personal Identity to Bioethics,’ David Shoemaker argues that, contrary to common opinion, considerations of personal identity have no relevance to certain important debates in bioethics, such as abortion, the definition of death, and advanced directives. My aim is to show that Shoemaker is mistaken concerning the relevance of personal identity to the abortion debate – in particular, to Don Marquis’ well-known anti-abortion argument. After highlighting two ways in which considerations of personal identity seem relevant to Marquis’ argument, I will explain Shoemaker’s reasons for thinking personal identity irrelevant to it. Then I will explain why I believe Shoemaker’s argument to be unsound. According to Marquis, most abortions are seriously prima facie immoral because most abortions deprive the fetus of the valuable future it would have had had the abortion not been performed. The sort of future we take away from a fetus by aborting it is, typically, the same sort of future you and I have in store: a future as a person, with valuable experiences and worthwhile projects – a ‘future like ours.’ Just as it would be wrong to take this future away from you by killing you, so it is with human fetuses. It would certainly seem that whether Marquis’ argument can succeed depends upon issues of personal identity. For in order for the killing of a fetus to deprive it of a future like ours, it must be the case that, were the fetus not killed, there would later be some future person who is identical to the fetus – the person the fetus would grow up to become. To put it another way, killing a fetus can deprive it of a future like ours only if each of us was once a fetus. But whether each of us was once a fetus turns on the nature of personal identity. Different theories of personal identity will give different answers. Indeed, the two leading theories of personal identity – the psychological theory and the biological, or animalist, theory – give different answers. The psychological theory of personal identity has the consequence that you were never a fetus – or at least never an early-term fetus – since you lack the requisite psychological connections to the early-term fetus that was in your mother’s womb several months before your birth. The psychological theory thus implies that killing an early-term fetus does not deprive it of a future like ours. The biological theory of personal identity, by contrast, implies that each of us was indeed once an early-term fetus, and even an embryo. The human organism that is in your chair right now surely used to be an embryo, and according to the biological theory, you just are this organism. The biological theory of personal identity is therefore friendly to Marquis’ argument, while the psychological theory is unfriendly to it. Indeed, it would seem that the psychological theory would positively undermine Marquis’ argument, while the biological theory leaves the argument standing. This is the first way in which the question of personal identity is relevant to Marquis’ argument. The second way, which is the focus of Shoemaker’s discussion, has to do with whether Marquis’ argument commits its advocates to the view that contraception, or any failure to conceive, is as immoral as abortion.