The birthplace of Pythagoras is uncertain. He is generally called the Samian, and we know, at all events, that he lived for some time in that island, during or immediately before the famous tyranny [43] of Polycrates. All manner of legends are told of the travels of Pythagoras to Egypt, Chaldaea, Phoenicia, and even to India. Others tell of a mysterious initiation at the sacred cave of Jupiter in Crete, and of a similar ceremony at the Delphic oracle. What is certain is that at some date towards the end of the sixth century B.C. he removed to Southern Italy, which was then extensively colonised by Greeks, and that there he became a great philosophic teacher, and ultimately even a predominating political influence. [46] He instituted a school in the strictest sense, with its various grades of learners, subject for years to a vow of silence, holding all things in common, and admitted, according to their approved fitness, to {23} [47] successive revelations of the true doctrine of the Master. Those in the lower grades were called Listeners; those in the higher, Mathematicians or Students; those in the most advanced stage, Physicists or Philosophers. With the political relations of the school we need not here concern ourselves. In Crotona and many other Greek cities in Italy Pythagoreans became a predominant aristocracy, who, having learned obedience under their master, applied what they had learned in an anti-democratic policy of government. This lasted for some thirty years, but ultimately democracy gained the day, and Pythagoreanism as a political power was violently rooted out. Returning to the philosophy of Pythagoras, in its relation to the general development of Greek theory, we may note, to begin with, that it is not necessary, or perhaps possible, to disentangle the theory of Pythagoras himself from that of his followers, Philolaus and others. The teaching was largely oral, and was developed by successive leaders of the school. The doctrine, therefore, is generally spoken of as that, not of Pythagoras, but of the Pythagoreans. Nor can we fix for certain on one fundamental conception, upon which the whole structure of their doctrine was built. [52] One dictum we may start with because of its analogies with what has been said of the earlier {24} philosophies. The universe, said the Pythagoreans, was constituted of _indefinites_ and _definers_, _i.e._ of that which has no character, but has infinite capacities of taking a character; and secondly, of things or forces which impose a character upon this. Out of the combination of these two elements or principles all knowable [53] existences come into being. "All things," they said, "as known have _Number_; and this number has two natures, the Odd and the Even; the known thing is the Odd-Even or union of the two." [66]