Full Idea
Williams insisted that the feelings we have in situations of moral conflict show that the 'structure' of moral judgements is unlike that of assertions expressing beliefs.
Gist of Idea
Moral conflicts have a different feeling and structure from belief conflicts
Source
report of Bernard Williams (Ethical consistency [1965]) by Philippa Foot - Moral Realism and Moral Dilemma p.36
Book Reference
Foot,Philippa: 'Moral Dilemmas' [OUP 2002], p.36
A Reaction
Foot presents this as a key reason for the non-cognitivist view of ethics, and her paper attacks it. I don't usually react to moral disagreement with the same vigour I have when I think a belief is untrue. It may just be uncertainty, though.