XXXI. The disciples of Zeno were very numerous. The most eminent were, first of all, Persæus, of Cittium, the son of Demetrius, whom some call a friend of his, but others describe him as a servant and one of the amanuenses who were sent to him by Antigonus, to whose son, Halcyoneus, he also acted as tutor. And Antigonus once, wishing to make trial of him, caused some false news to be brought to him that his estate had been ravaged by the enemy; and as he began to look gloomy at this news, he said to him, “You see that wealth is not a matter of indifference.” The following works are attributed to him. One on Kingly Power; one entitled the Constitution of the Lacedæmonians; one on Marriage; one on Impiety; the Thyestes; an Essay on Love; a volume of Exhortations; one of Conversations; four of Apophthegms; one of Reminiscences; seven treatises, the Laws of Plato. The next was Ariston, of Chios, the son of Miltiades, who was the first author of the doctrine of indifference; then Herillus, who called knowledge the chief good; then Dionysius, who transferred this description to pleasure; as, on account of the violent disease which he had in his eyes, he could not yet bring himself to call pain a thing indifferent. He was a native of Heraclea; there was also Sphærus, of the Bosphorus; and Cleanthes, of Assos, the son of Phanias, who succeeded him in his school, and whom he used to liken to tablets of hard wax, which are written upon with difficulty, but which retain what is written upon them. And after Zeno’s death, Sphærus became a pupil of Cleanthes. And we shall speak of him in our account of Cleanthes. These also were all disciples of Zeno, as we are told by Hippobotus, namely:—Philonides, of Thebes; Callippus, of Corinth; Posidonius, of Alexandria; Athenodorus, of Soli; and Zeno, a Sidonian. XXXII. And I have thought it best to give a general account of all the Stoic doctrines in the life of Zeno, because he it was who was the founder of the sect. He has written a great many books, of which I have already given a list, in which he has spoken as no other of the Stoics has. And his doctrines in general are these. But we will enumerate them briefly, as we have been in the habit of doing in the case of the other philosophers.