caught the spark, and the flame of philosophy was never extinguished on the Athenian altars for almost a thousand years, until the Emperor Justinian closed the philosophic schools in 529 A.D. Now philosophy aimed from the very first to explain the origin and structure of the universe by reducing all things to a single principle, or to a few principles at most. The purpose of the philosopher was to carry out a more systematic search for unity than the thought of the poet or of the ordinary man could accomplish. We have seen how Hesiod and the Orphics tried by cosmogonies to explain the origin of the world. The philosophers turned to physical science for their explanation. But in every case their work was from its very nature antagonistic to popular polytheism, which saw a separate divinity in every phenomenon. It was inevitable that the conflict should become an open one sooner or later. Xenophanes of Colophon (flor. c. 540 B.C.) was the first to enter the lists. Driven into exile by civil disturbances at about the age of twenty-five, he lived most of his life in Sicily. He was as much a social and religious reformer and satirist as philosopher. With a frankness which passed beyond the freedom of his age he struck at the popular beliefs with regard to the gods, which taught that the gods were born and had clothes and voices and forms like mortals. He illustrated the folly of the Greeks in making the gods after their own image by reminding them that the Ethiopians made their gods flat-nosed and black, and the Thracians theirs blue-eyed and red-haired, while if cattle and horses and lions had but hands and could draw and mould and fashion like men, then each would draw and fashion the gods in his own image.[155] For the current notions of divinity he held Homer and Hesiod responsible and charged that these poets had attributed to the gods everything that was reckoned as shame and reproach among men—stealing, adultery, and cheating.[156] He likewise opposed the doctrine that the gods had taught men their knowledge, but declared that man had always learned through experience and investigation the better way for himself.[157] Xenophanes went even further than this and used the science of his day to prove that what was regarded as the appearances of the gods was merely meteorological phenomena. In the place of many gods he declared that there was but one, and he not like mortal men either in form or intelligence, but that he was wholly sight, wholly intelligence, wholly hearing—that is to say, god and the universe are identical, and the cosmos is eternal, sentient, and intelligent.[158] There could hardly have been a greater contrast than between this pantheism and the polytheism of the day. It is true that Xenophanes offers no adequate explanation of the way in which phenomena arise; he does not solve the problem of deriving the transient out of that which is permanent and fixed. But nevertheless he crudely anticipated