Turning to Philosophical Literature, we find that the early Greek and Indian philosophers have many points in common. Some of the leading doctrines of the Eleatics, that God and the universe are one, that everything existing in multiplicity has no reality, that thinking and being are identical, are all to be found in the philosophy of the Upanishads and the Vedanta system, which is its outcome. Again, the doctrine of Empedocles, that nothing can arise which has not existed before, and that nothing existing can be annihilated, has its exact parallel in the characteristic doctrine of the Sankhya system about the eternity and indestructibility of matter. According to Greek tradition, Thales, Empedocles, Anaxagoras, Democritus, and others undertook journeys to Oriental countries in order to study philosophy. Hence there is at least the historical possibility of the Greeks having been influenced by Indian thought through Persia. Whatever may be the truth in the cases just mentioned, the dependence of Pythagoras on Indian philosophy and science certainly seems to have a high degree of probability. Almost all the doctrines ascribed to him, religious, philosophical, mathematical, were known in India in the sixth century B.C. The coincidences are so numerous that their cumulative force becomes considerable. The transmigration theory, the assumption of five elements, the Pythagorean theorem in geometry, the prohibition as to eating beans, the religio-philosophical character of the Pythagorean fraternity, and the mystical speculations of the Pythagorean school, all have their close parallels in ancient India. The doctrine of metempsychosis in the case of Pythagoras appears without any connection or explanatory background, and was regarded by the Greeks as of foreign origin. He could not have derived it from Egypt, as it was not known to the ancient Egyptians. In spite, however, of the later tradition, it seems impossible that Pythagoras should have made his way to India at so early a date, but he could quite well have met Indians in Persia.