Letters 117.10

The objector replies: “It is only an accessory of wisdom.” Very well, then, I say, this quality which you call being wise—does it actively produce wisdom, or is it a passive concomitant of wisdom? It is corporeal in either case. For that which is acted upon and that which acts, are alike corporeal; and, if corporeal, each is a Good. The only quality which could prevent it from being a Good, would be incorporeality.

Seneca, Letters to Lucilius 117.10, translated by Richard Mott Gummere