Most of us are brought up to think that stealing is wrong, that you should keep your promises, that morality requires us not to hurt others, and so on. We recognize that moral principles like these may need to be made a bit sharper to deal with exceptions, such as its being morally permissible to hurt someone to defend yourself from them. But it is commonplace to think that there are correct moral principles at least in their vicinity. Moral particularism, as it figures in the past few decades of moral philosophy, is a family of views united by an opposition to giving moral principles a fundamental or important role in morality. 1 particularism challenges the project of ambitious moral theory in the traditional style of Kant, Mill, and most other major figures in the history of moral philosophy. Moral generalism is, likewise, not a single sharply defined position but a family of views united by the thought that moral principles do play some such fundamental or important role.this chapter first distinguishes two central roles that moral principles have traditionally been asked to play in moral theory and three different forms which opposition to principles playing either of those roles has taken. It then surveys some of the leading arguments for and against thinking that principles play these central roles and notes various questions that remain live.