Letter 89 — On the Parts of Philosophy (§5)

“Certain persons have defined wisdom as the knowledge of things divine and things human. Still others say: “Wisdom is knowing things divine and things human, and their causes also.” This added phrase seems to me to be superfluous, since the causes of things divine and things human are a part of the divine system. Philosophy also has been defined in various ways; some have called it “the study of virtue,” others have referred to it as “a study of the way to amend the mind,” and some have named it “the search for right reason.””