Phronēsis

Phronēsis (φρόνησις) is practical wisdom, prudence, good judgment — the excellence of mind that knows how to live and act well. It comes from phronein, 'to think' or 'to be of sound mind', rooted in phrēn, which the Greeks took to be a seat of thought and feeling.

The wisdom of action

Aristotle gave the word its classic definition in the Nicomachean Ethics, where he carefully distinguishes it from sophia. Sophia is theoretical wisdom about things eternal and unchanging; phronēsis is concerned with the variable world of human action — with deliberating rightly about what is good for oneself and others, here and now, in all the particularity of a situation. It cannot be reduced to rules, for it is precisely the skill of discerning what this case requires.

The captain of the virtues

For Aristotle phronēsis is indispensable to character: the moral virtues set the right ends, but practical wisdom finds the right means and hits the mean between excess and defect. One cannot be truly good, he held, without it, nor practically wise without virtue — the two grow up together. It is the intellectual virtue that steers a whole life toward flourishing.