Letter 76 — On Learning Wisdom in Old Age (§16)

“It is this that is called virtue; this is what we mean by “honourable”; it is man’s unique good. For since reason alone brings man to perfection, reason alone, when perfected, makes man happy. This, moreover, is man’s only good, the only means by which he is made happy. We do indeed say that those things also are goods which are furthered and brought together by virtue,—that is, all the works of virtue; but virtue itself is for this reason the only good, because there is no good without virtue.”