Abstract

Don Marquis has argued that abortion is immoral because it deprives the fetus of a "future like ours." But Marquis's argument fails by incorrectly assuming that a zygote and the late-term fetus with which it is physically continuous are numerically identical. In fact, the identity of a prebirth human (PBH) across gestation is indeterminate, such that it is determinately morally permissible to destroy an early-term PBH and determinately immoral to destroy a late-term PBH. Beginning at some indeterminate point during gestation and ending at some indeterminate point later in gestation, destroying a PBH is neither determinately morally permissible nor determinately immoral.