Intuitionism—in some form or another—is the most widely recognized and thoroughly discussed method of justification for moral theories. It rests on the claim that a moral theory must not deviate too much from our pre-theoretical moral convictions. In some form or another, this methodology goes back at least as far as Aristotle, and has been discussed, refined, and defended by such contemporary philosophers as John Rawls and Norman Daniels.There is, however, another methodology for constructing and defending moral theories. It draws (...) on premises about human nature or the nature of persons to support conclusions about the nature and structure of morality. This method—which I will call thenature to morality methodology—evaluates a moral claim or moral theory on the basis of its relation to some facts about the kind of beings we are. For brevity, I will use the term ‘nature-claims’ to refer to claims about human nature or the nature of persons, and the term ‘nature-facts’ to refer to true nature-claims. The nature-claims that have been used to support or criticize various moral theories include claims about human motivation, personal identity, the human soul, and the conceptual features of personhood or rational agency. (shrink)