Full Idea
It makes sense to say that a man acts out of vanity on a particular occasion although he is not in general vain, or even vain about this kind of thing.
Gist of Idea
People can act out of vanity without being vain, or even vain about this kind of thing
Source
Philippa Foot (Free Will as Involving Determinism [1957], p.69)
Book Reference
Foot,Philippa: 'Virtues and Vices' [Blackwell 1981], p.69
A Reaction
Aristotle tells us that virtues and vices are habits, and also have an intellectual component, implying that the person believes in that sort of behaviour. Anyone can have 'a little moment of vanity'.