wrote a few letters. There are some men too who have written one work only, Melissus, Parmenides, and Anaxagoras; but Zeno wrote many works, Xenophanes still more; Democritus more, Aristotle more, Epicurus more, and Chrysippus more.
XII. Again, of philosophers some derived a surname from cities, as, the Elians, and Megaric sect, the Eretrians, and the Cyrenaics. Some from the places which they frequented, as the Academics and Stoics. Some from accidental circumstances, as the Peripatetics; or, from jests, as the Cynics. Some again from their dispositions, as the Eudæmonics; some from an opinion, as the Elenctic, and Analogical schools. Some from their masters, as the Socratic and Epicurean philosophers; and so on. The Natural Philosophers were so called from their study of nature; the Ethical philosophers from their investigation of questions of morals (περὶ τὰ ἔθη). The Dialecticians are they who devote themselves to quibbling on words.
XIII. Now there are three divisions of philosophy. Natural, Ethical, and Dialectic. Natural philosophy occupies