[Marcus,] the one also [called] Antoninus; emperor of [the] Romans,[1] the philosopher admirable in every respect. He attended the lectures of many different [instructors], but ultimately ended up as a student of Sextus, a philosopher from Boeotia, in Rome itself, seeking him out and going to [his] house. A certain rhetorician named Lucius, an associate of the rhetorician Herodes Atticus, asked him, as he was going out, where he was going and why. And Marcus responded, "[It is] good even for an aging man to learn. I am on my way to Sextus the philosopher to learn things I do not yet know." And Lucius lifted up his hand to heaven and said "o Helios, the emperor of Rome in his old age is still taking up his slate and going to his teacher's house. But my king Alexander died at thirty-two."[2]
This man recorded the conduct of his own life in 12 books.[3]