These are the times of the oldest wise men and philosophers among the Greeks. And that the most of them were barbarians by extraction, and were trained among barbarians, what need is there to say? Pythagoras is shown to have been either a Tuscan or a Tyrian. And Antisthenes was a Phrygian. And Orpheus was an Odrysian or a Thracian. The most, too, show Homer to have been an Egyptian. Thales was a Phoenician by birth, and was said to have consorted with the prophets of the Egyptians; as also Pythagoras did with the same persons, by whom he was circumcised, that he might enter the adytum and learn from the Egyptians the mystic philosophy. He held converse with the chief of the Chaldeans and the Magi; and he gave a hint of the church, now so called, in the common hall which he maintained.
Source: Translated by William Wilson. From Ante-Nicene Fathers, Vol. 2. Edited by Alexander Roberts, James Donaldson, and A. Cleveland Coxe. (Buffalo, NY: Christian Literature Publishing Co., 1885.)