 The nonidentity problem raises questions regarding the obligations we think we have in respect of people who, by our own acts, are caused both to exist and to have existences that are, though worth having, unavoidably flawed – existences, that is, that are flawed if those people are ever to have them at all. If a person’s existence is unavoidably flawed, then the agent’s only alternatives to bringing that person into the flawed existence are to bring no one into existence at all or to bring a different person – a nonidentical but better off person – into existence in place of the one person. If the existence is worth having and no one else’s interests are at stake, it is unclear on what ground morality would insist that the choice to bring the one person into the flawed existence is morally wrong. And yet at the same time – as we shall see – it seems that in some cases such a choice clearly is morally wrong. The nonidentity problem is the problem of resolving this apparent paradox.