III. Some again (one of whom is Chœrilus the poet) say that he was the first person who affirmed that the souls of men were immortal; and he was the first person, too, who discovered the path of the sun from one end of the ecliptic to the other: and who, as one account tells us, defined the magnitude of the sun as being seven hundred and twenty times as great as that of the moon. He was also the first person who called the last day of the month the thirtieth. And likewise the first to converse about natural philosophy, as some say. But Aristotle and Hippias say that he attributed souls also to lifeless things, forming his conjecture from the nature of the magnet, and of amber. And Pamphile relates that he, having learnt geometry from the Egyptians, was the first person to describe a right-angled triangle in a circle, and that he sacrificed an ox in honour of his discovery. But others, among whom is Apollodorus the calculator, say that it was Pythagoras who made this discovery. It was Thales also who carried to their greatest point of advancement the discoveries which Callimachus in his iambics says were first made by Euphebus the Phrygian, such as those of the scalene angle, and of the triangle, and of other things which relate to investigations about lines. He seems also to have been a man of the greatest wisdom in political matters. For when Crœsus sent to the Milesians to invite them to an alliance, he prevented them from agreeing to it, which step of his, as Cyrus got the victory, proved the salvation of the city. But Clytus relates, as Heraclides assures us, that he was attached to a solitary and recluse life. IV. Some assert that he was married, and that he had a son named Cibissus; others, on the contrary, say that he never had a wife, but that he adopted the son of his sister; and that once being asked why he did not himself become a father, he answered, that it was because he was fond of children. They say, too, that when his mother exhorted him to marry, he said, “No, by Jove, it is not yet time.” And afterwards, when he was past his youth, and she was again pressing him earnestly, he said, “It is no longer time.” V. Hieronymus, of Rhodes, also tells us, in the second book of his Miscellaneous Memoranda, that when he was desirous to show that it was easy to get rich, he, foreseeing that there would be a great crop of olives, took some large plantations of olive trees, and so made a great deal of money.