David Shoemaker

Ethical theories must include an account of the concept of a person. They also need a criterion of personal identity over time. This requirement is most needed in theories involving distributions of resources or questions of moral responsibility. For instance, in using ethical theories involving compensations of burdens, we must be able to keep track of the identities of persons earlier burdened in order to ensure that they are the same people who now are to receive the compensatory benefits. Similarly, in order to attribute moral responsibility to someone for an act, we must be able to determine that that person is the same person as the person who performed the act. Unfortunately, ethical theories generally include a concept of a person and criteria of personal identity either as notions implied or presupposed by the already worked out theory, with little or no argument given in support of them. But both approaches are unsatisfactory, for each runs the risk of ignoring certain fundamental features of the way persons actually are. What is needed first is a plausible metaphysical account of persons and personal identity to which an ethical theory might then conform and apply. Derek Parfit has attempted to provide such an account in Reasons and Persons, where he argues for what he calls the reductionist view of persons and personal identity and then attempts to show how such a conception provides a metaphysical background that lends important partial support to utilitarianism. 1 But Parfit’s metaphysical view is neutral between two possible conceptions of personhood, and utilitarianism presupposes the truth of the more radical of the two conceptions, which precludes the possibility of there being a class of goods crucial to any plausible ethical theory. Utilitarianism thus presupposes a wildly implausible conception of persons, and so is itself implausible

Personal Identity and Ethics provides a lively overview of the relationship between the metaphysics of personal identity and ethics. How does personal identity affect our ethical judgments? It is a commonplace to hold that moral responsibility for past actions requires that the responsible agent is in some relevant respect identical to the agent who performed the action. Is this true? On the other hand, can ethics constrain our account of personal identity? Do the practical requirements of moral theory commit us to holding that persons do remain identical over time? Or is it the case that personal identity is not, in fact, relevant to ethics? Shoemaker provides the first comprehensive examination of these issues for the undergraduate audience. Topics include personal identity and prudential rationality; personal identity's significance for moral responsibility and ethical theory; and the practical consequences of accounts of personal identity for issues such as abortion, stem cell research, cloning, advance directives, populations ethics, multiple personality disorder, and the definition of death.