Full Idea
Virtue ensures the correctness of the end at which we aim, and prudence that of the means towards it.
Clarification
'Prudence' is Greek word 'phronesis', for which the translation 'practical reason' is nowadays preferred
Gist of Idea
Virtue ensures that we have correct aims, and prudence that we have correct means of achieving them
Source
Aristotle (Nicomachean Ethics [c.334 BCE], 1144a07)
Book Reference
Aristotle: 'Ethics (Nicomachean)', ed/tr. ThomsonJ A K/TredennickH [Penguin 1976], p.222
A Reaction
I'm not wholly clear about how virtue identifies correct aims. Virtue finds the mean, but how? Prudence is busy with strategy. Theoretical reason stands back from the world. A gap in the theory?