 The emergence of a philosophical literature analyzing and invoking what has become known as “the moral/conventional distinction” can be traced to a growing awareness, among philosophers, of the enormously influential work of developmental psychologist Elliot Turiel and his many collaborators, most notably Melanie Killen, Larry Nucci, and Judith  Smetana.[2]  This group of researchers are often called “social domain theorists”. The sections 3 through 10 of this entry will focus on debates, in both psychology and philosophy, about the existence, the nature, and the importance of the moral/conventional distinction.  Section 11  will consider some of the ways in which the social domain theorists’ account of the moral/conventional distinction, and related ideas, have been used in philosophical discussions of a variety of issues.