This chapter describes and defends moral pluralist theories, that is, ethical theories that hold there is no one single principle to which all other principles may be reduced. It overviews Frankena's 'mixed deontological theory', Beauchamp and Childress' 'Principlism' and Gert's 'common morality', emphasizing the commonalities across these pluralist theories. It responds to the major philosophical challenges to moral pluralism, and - drawing especially on Beauchamp and Childress' work - develops a three-stage process of specification and conflict resolution to resolve clashes between principles in cases of conflict.