Letters 20.5

Therefore, to omit the ancient definitions of wisdom and to include the whole manner of human life, I can be satisfied with the following: “What is wisdom? Always desiring the same things, and always refusing the same things.” You may be excused from adding the little proviso,—that what you wish, should be right; since no man can always be satisfied with the same thing, unless it is right.

Seneca, Letters to Lucilius 20.5, translated by Richard Mott Gummere