Accounts of moral reasoning have tended either to ignore the differences in what men count as good reasons for their moral judgments, or, in emphasizing these differences, to imply that anything whatsoever can count as a moral reason. This book shows that both of these positions rest on a mistaken assumption, and by rejecting this assumption brings out important features of moral discourse. Although moral disagreement is seen to be far more radical than empirical disagreement, a framework of agreement is shown to be a precondition of moral discourse, and even of the possibility of individual moral decision.