Letter 89 — On the Parts of Philosophy (§13)

“Aristo of Chios remarked that the natural and the rational were not only superfluous, but were also contradictory. He even limited the “moral,” which was all that was left to him; for he abolished that heading which embraced advice, maintaining that it was the business of the pedagogue, and not of the philosopher—as if the wise man were anything else than the pedagogue of the human race!”