Full Idea
Maybe so far from forming a unity ...., the virtues actually conflict with each other: that is, if someone has one of them he inevitably fails to have some other. ...Maybe he a man can only be good in one way be being bad in another.
Gist of Idea
Maybe virtues conflict with each other, if some virtue needs a vice for its achievement
Source
Philippa Foot (Moral Realism and Moral Dilemma [1983], p.57)
Book Reference
Foot,Philippa: 'Moral Dilemmas' [OUP 2002], p.57
A Reaction
She suggests the self-loathing needed to rein in evil desires. She cites Nietzsche having a similar thought. Presumably the ideal virtuous person has no such conflicts, and the self-loathing undermines eudaimonia. Unity in theory but not in practice?