Are animals – and persons – morally “replaceable”?

Abstract This article critically examines Peter Singer’s arguments for two conclusions: first, that non-self-conscious animals are “replaceable” in the sense that the killing of one can be morally offset by the creation of another; and, second, that persons are not replaceable in this sense. Much of the support that Singer provides for the second of these claims is found in his defense of “the debit view of preferences,” which he advanced in response to an earlier critic of his preference utilitarianism. The author argues that the debit view is untenable for several reasons. The author argues further that Singer’s appeal to Parfit’s Non-Identity Problem in support of the replaceability of non-self-conscious individuals is also mistaken. In spite of these problems, however, the author contends that there is a genuine insight in Singer’s “replaceability thesis,” and develops and defends different arguments for both the claim that some animals – and, indeed, some human beings – are replaceable and the claim that persons are not.