How should we understand the question "Why be moral?" Can we answer this question? If so, how? In this paper I develop an exemplarist theory of practical moral justification; that is, a theory of the justification of the prima facie moral things that we do, not the moral beliefs that we have. I take as my starting point that morality is, essentially, a set of practices in which all persons, in virtue of their being persons, participate. I argue that skillful practitioners of these various practices should be understood as moral authorities, and that the appeal to a moral authority for the purpose of one's justifying one's moral doings is necessarily justified for the appealer whenever she is practicing the same practice as the moral authority. This theory holds that moral authorities, so circumscribed, are Authoritative Exemplars, and as the appeal to their authority is necessarily justified they are able to provide a foundation for practical moral justifications, and thus rebutting the objection that all such justifications will run to regress. Among other things this account allows us to interpret the "Why be moral?" question as a question asking for more than can be had posed from a position of misunderstanding the nature of morality and practical moral justification. We cannot answer the "Why be moral?" question any more than we can answer the "Why be human?" question.