The account just given of the views of Pythagoras is, no doubt, conjectural and incomplete. We have simply assigned to him those portions of the Pythagorean system which appear to be the oldest, and it has not even been possible at this stage to cite fully the evidence on which our discussion is based. It will only appear in its true light when we have examined the second part of the poem of Parmenides and the system of the later Pythagoreans.[264] For reasons which will then be apparent, I do not venture to ascribe to Pythagoras himself the theory of the earth’s revolution round the central fire. It seems safest to suppose that he still adhered to the geocentric hypothesis of Anaximander. In spite of this, however, it will be clear that he opened a new period in the development of Greek science, and it was certainly to his school that its greatest discoveries were directly or indirectly due. When Plato deliberately attributes some of his own most important discoveries to the Pythagoreans, he was acknowledging in a characteristic way the debt he owed them. Footnote 264: See Chap. IV. §§ 92-93, and Chap. VII. §§ 150-152. II. XENOPHANES OF KOLOPHON [Sidenote: Life.] 55. We have seen how Pythagoras identified himself with the religious movement of his time; we have now to consider a very different manifestation of the reaction against that view of the gods which the poets had made familiar to every one. Xenophanes denied the anthropomorphic gods altogether, but was quite unaffected by the revival of more primitive ideas that was going on all round him. We still have a fragment of an elegy in which he ridiculed Pythagoras and the doctrine of transmigration. “Once, they say, he was passing by when a dog was being ill-treated. ‘Stop!’ he said, ‘don’t hit it! It is the soul of a friend! I knew it when I heard its voice.’”[265] We are also told that he opposed the views of Thales and Pythagoras, and attacked Epimenides, which is likely enough, though no fragments of the kind have come down to us.[266] His chief importance lies in the fact that he was the author of the quarrel between philosophy and poetry which culminated in Plato’s _Republic_. Footnote 265: See fr. 7 (= 18 Karst.), _ap._ Diog. viii. 36 (R. P. 88). Footnote 266: Diog. ix. 18 (R. P. 97). We know that Xenophanes referred to the prediction of an eclipse by Thales (Chap. I. p. 41, _n._ 62). We shall see that his own view of the sun was hardly consistent with the possibility of such a prediction, so it may have been in connexion with this that he opposed him.