Alexander to Aristotle, greeting. You have not done well to publish your books of oral doctrine; for what is there now that we excel others in, if those things which we have been particularly instructed in be laid open to all? For my part, I assure you, I had rather excel others in the knowledge of what is excellent, than in the extent of my power and dominion. Farewell.

…Alexander the Great, in a letter to his childhood teacher, Aristotle, as reported by Plutarch in his Life of Alexander.