These, then, are the beginnings, these are the successive masters, these are the divisions, and schools of philosophy. XIV. Moreover, it is not long ago, that a new Eclectic school was set up by Potamo, of Alexandria, who picked out of the doctrines of each school what pleased him most. And as he himself says, in his Elementary Instruction, he thinks that there are certain criteria of truth: first of all the faculty which judges, and this is the superior one; the other that which is the foundation of the judgment, being a most exact appearance of the objects. And the first principles of everything he calls matter, and the agent, and the quality, and the place. For they show out of what, and by what, and how, and where anything is done. The end is that to which everything is referred; namely, a life made perfect with every virtue, not without the natural and external qualities of the body. But we must now speak of the men themselves; and first of all about Thales. LIFE OF THALES. I. Thales, then, as Herodotus and Duris and Democritus say, was the son of Euxamius and Cleobule; of the family of the Thelidæ, who are Phœnicians by descent, among the most noble of all the descendants of Cadmus and Agenor, as Plato testifies. And he was the first man to whom the name of Wise was given, when Damasius was Archon at Athens, in whose time also the seven wise men had that title given to them, as Demetrius Phalereus records in his Catalogue of the Archons. He was enrolled as a citizen at Miletus when he came thither with Neleus, who had been banished from Phœnicia; but a more common statement is that he was a native Milesian, of noble extraction. II. After having been immersed in state affairs he applied himself to speculations in natural philosophy; though, as some people state, he left no writings behind him. For the book on Naval Astronomy, which is attributed to him is said in reality to be the work of Phocus the Samian. But Callimachus was aware that he was the discoverer of the Lesser Bear; for in his Iambics he speaks of him thus: And, he, ’tis said, did first compute the stars Which beam in Charles’s wain, and guide the bark Of the Phœnician sailor o’er the sea. According to others he wrote two books, and no more, about the solstice and the equinox; thinking that everything else was easily to be comprehended. According to other statements, he is said to have been the first who studied astronomy, and who foretold the eclipses and motions of the sun, as Eudemus relates in his history of the discoveries made in astronomy; on which account Xenophanes and Herodotus praise him greatly; and Heraclitus and Democritus confirm this statement.