Full Idea
The virtues are corrective, each one standing at a point at which there is some temptation to be resisted or deficiency of motivation to be made good.
Gist of Idea
Virtues are corrective, to resist temptation or strengthen motivation
Source
Philippa Foot (Virtues and Vices [1978], II)
Book Reference
Foot,Philippa: 'Virtues and Vices' [Blackwell 1981], p.8
A Reaction
A beautifully simple and accurate observation, which I don't remember meeting in Aristotle (...though she cites him as saying that virtues concern what is difficult for us). Justice and charity are given as examples of inadequate motivation.