Phronesis, or practical wisdom, or prudence, is, to me, a profound concept. Aristotle identifies phronesis as one of the dianoetic virtues, that is, those intellectual virtues that characterize the well-ordered mind. The dianoetic virtues are: Sophia (wisdom of first principles), episteme (scientific knowledge), phronesis (practical wisdom), techne (craft knowledge), and nous (intuition).
Phronesis is important to rhetoric in a variety of ways. The links here each elucidate one facet of its importance.
Much more to come . . .