Full Idea
If justice is a virtue it must make action good by disposing its possessor to goodness in practical rationality; the latter consisting of the right recognition of reasons, and corresponding action.
Gist of Idea
Possessing the virtue of justice disposes a person to good practical rationality
Source
Philippa Foot (Rationality and Virtue [1994], p.174)
Book Reference
Foot,Philippa: 'Moral Dilemmas' [OUP 2002], p.174
A Reaction
This somewhat inverts Aristotle, who says the possessing of good practical reason is the key to acquiring the virtues. Foot suggests that possessing the virtue promotes the practical rationality. Someone can be sensible without being virtuous.