We tend to think of the moral agent as someone who engages in positive actions, who is honest, generous, brave, and so on. However, as David Braybrooke pointed out in an important essay of the 1980s, '[A]ll [social] rules are at bottom or canonically rules of one sort, namely prohibitions.' The basic form of a social rule is the 'overgeneralised formula' completing a Thou Shalt Not phrase. Departing from this insight, I aim to resolve the impasse between expressivism and moral realism. This can be accomplished by analysing separately first, the anthropology of moral discourse, including its roots in moralistic aggression (Trivers); second, the ideational content of normative claims, which involves possible world thinking; and third, the concrete social processes by which the acceptability of some claims is established.
