Full Idea
It is a fundamental criticism of many ethical theories that their accounts of moral conflict and its resolution do not do justice to the facts of regret...: basically because they eliminate from the scene the ought that is not acted upon.
Gist of Idea
Many ethical theories neglect the power of regretting the ought not acted upon
Source
Bernard Williams (Ethical consistency [1965], p.175), quoted by Philippa Foot - Moral Realism and Moral Dilemma p.39
Book Reference
Foot,Philippa: 'Moral Dilemmas' [OUP 2002], p.39
A Reaction
[p.175 in Problems of the Self] Williams seems to have initiated this idea. It doesn't matter much for Kantians and Utilitarians (any more than a wrong answer in maths), but it matters if character is the focus. The virtuous have regrets.