Ordinarily we assume that people have reasons for caring about their own well-being which are different in kind from the reasons they have for caring about the well-being of others. Concern for others may in some instances be greater than concern for oneself, but we believe it to have a different basis. Let’s call this class of reasons ‘self-interested reasons’ or ‘reasons of self-concern’. 1 The existence of self-interested reasons raises obvious questions about how to adjudicate their inevitable conflicts with impersonal, moral reasons. One interesting approach to these questions has developed out of work on the metaphysics of diachronic personal identity. Some philosophers in this field, most notably Derek Parfit, have argued that our idea that there are self-interested reasons which can stand as competitors to moral ones rests on a metaphysical mistake. We believe that there is a deep connection between the different temporal parts of a person’s life, Parfit says, but reflection will show that this cannot be the case. Once we recognize this fact, he continues, we will see that self-interested reasons of the sort we believe we have do not exist.