The chief figures in the philosophical history of the period were Pythagoras of Samos and Xenophanes of Kolophon. Both were Ionians by birth, and yet both spent the greater part of their lives in the West. We see from Herodotos how the Persian advance in Asia Minor occasioned a series of migrations to Sicily and Southern Italy;[170] and this, of course, made a great difference to philosophy as well as to religion. The new views had probably grown up so naturally and gradually in Ionia that the shock of conflict and reaction was avoided; but that could no longer be so, when they were transplanted to a region where men were wholly unprepared to receive them. Footnote 170: Cf. Herod. i. 170 (advice of Bias); vi. 22 sqq. (Kale Akte). Another, though a somewhat later, effect of these migrations was to bring Science into contact with Rhetoric, one of the most characteristic products of Western Hellas. Already in Parmenides we may note the presence of that dialectical and controversial spirit which was destined to have so great an influence on Greek thought, and it was just this fusion of the art of arguing for victory with the search for truth that before long gave birth to Logic. [Sidenote: The religious revival.] 33. Most important of all in its influence on philosophy was the religious revival which culminated about this time. The religion of continental Hellas had developed in a very different way from that of Ionia. In particular, the worship of Dionysos, which came from Thrace, and is barely mentioned in Homer, contained in germ a wholly new way of looking at man’s relation to the world. It would certainly be wrong to credit the Thracians themselves with any very exalted views; but there can be no doubt that, to the Greeks, the phenomenon of ecstasy suggested that the soul was something more than a feeble double of the self, and that it was only when “out of the body” it could show its true nature.[171] To a less extent, such ideas were also suggested by the worship of Demeter, whose mysteries were celebrated at Eleusis; though, in later days, these came to take the leading place in men’s minds. That was because they were incorporated in the public religion of Athens. Footnote 171: On all this, see Rohde, _Psyche_, pp. 327 sqq. It is probable that he exaggerated the degree to which these ideas were already developed among the Thracians, but the essential connexion of the new view of the soul with Northern worships is confirmed by the tradition over and over again.