Full Idea
The good of any virtue …is referable to the common good, to which justice directs, so that all acts of virtue can pertain to justice insofar as it directs man to the common good.
Gist of Idea
All acts of virtue relate to justice, which is directed towards the common good
Source
Thomas Aquinas (Summa Theologicae [1265], II-II Q58 5)
Book Reference
Aquinas,Thomas: 'On Law, Morality and Politics', ed/tr. Baumgarth,W. /Regan R. [Hackett 1988], p.152
A Reaction
Michael Sandel has recently lamented to fading of the concept of 'the common good' from our moral and political life. In which case this thought of Aquinas takes on great importance. I certainly like it. It seems to apply to courage, for example.