It is known that he wrote on Babylon and Meroe; he visited Egypt, and Diodorus Siculus states that he lived there for five years. He himself declared that among his contemporaries none had made greater journeys, seen more countries, and met more scholars than himself. He particularly mentions the Egyptian mathematicians, whose knowledge he praises. Theophrastus, too, spoke of him as a man who had seen many countries. During his travels, according to Diogenes Laërtius, he became acquainted with the Chaldean magi. "Ostanes", one of the magi accompanying Xerxes, was said to have taught him. It was also said he learned with the gymnosophists in his journey to India.