This important step in advance would appear to have been taken in the sixth century B.C. at latest, when the theories of the Orphic-Pythagorean school became widely diffused. M. Foucart, as we have seen in the last note, holds that this movement was due to the Egyptian researches carried on by the early Greek philosophers in the course of their travels; Rohde, on the other hand, regards it as a strictly national movement, and denies the late adoption of any alien faith of a highly developed character. In any case, it is certain that the theories of which Pythagoras was the most famous exponent assumed great prominence at this time. The leading principle of these was the doctrine of the soul’s rebirth on earth, in another body, after undergoing a process of purification in the Otherworld. It was one of the primary objects of the mysteries to ensure that the soul’s progress through the intermediate state should be as easy, and the conditions of its rebirth as favourable, as could be effected by the due performance of the mystical rites; and while the great progress of ethics, which with the early philosophers went hand and hand with philosophical speculation, effected a fuller recognition of moral conduct in this life as one of the means most conducive to the desired end, preference was still given, even among the righteous, to those who had undergone the initiation ceremony.[43] Professor Gardner even traces the Hades theory from the mystic rites (_loc. cit._); probably this derivation would only apply to that theory in its more fully developed form. He holds that the Orphic cult ‘occupies the background of religious life’ in Greece; that it was an enthusiastic type of religion, and capable of ready association with the ideals of such moral and political revivalists as Pythagoras and Empedocles. According to this authority, there were two foci of the Orphic cult: at Eleusis, and in the rites of Dionysos. M. Foucart, it will be remembered, denies any connection between Eleusis and the Orphic mysteries; in which contention he would appear to be supported by Plato, who speaks slightingly of the latter, while several passages in his writings testify to his respect for the mysteries of Eleusis. Certainly the two were respectively connected, originally, with the worship of two separate and widely different divinities, although, both having to do with the earth as the source and the renewer of life, they soon tended towards certain common developments. Perhaps we may not greatly err if we assume that the Orphic mysteries, in their most perfected form, were more especially concerned with the orgiastic ritual and with the doctrine of reincarnation, now reduced to a philosophical system, while in the Eleusinian school ritual became more closely connected with personal morality, thus assuming an aspect more strictly ‘religious,’ in the modern sense of the word.