In short, the initiate of the mysteries believed that they found in them a warrant of immortality. By the virtue of the rites their souls were united to their god; thus they became themselves divine, and were ensured an everlasting life. Inevitably, every Oriental religion affirmed that it held the only sacred tradition leading surely to eternal felicity. Outside the sect there was no certain salvation. But philosophy always opposed these claims. Philosophy, too, thought itself able to lead through wisdom to happiness in this world and in the next, and there was rivalry between it and the positive cults, as soon as it took on a religious character and set up religious claims. The Neo-Pythagoreans who formed esoteric communities opposed their purifications and initiations to those of the mysteries. But the eschatological doctrine, of which Posidonius was, if not the author, at least the powerful promoter, and which was to be taken up again and transformed by the Neo-Platonists, exempted the wise man from any obligation to religious observances as ensuring his immortality. He was no longer in need of sacraments and sacrifices, but could by his own unaided force become a pure intelligence, win the complete mastery of himself by reason, and thereafter be certain of raising himself to the godhead. At the most, certain thinkers granted a “propaedeutic” or preparatory value to ritual observances, and saw in them a means of predisposing the soul to ecstasy, but the mystic philosophers, of whom Plotinus represents the purest type, discarded for themselves all religious practices. Their proud doctrine places man alone face to face with God.[291] Or else, like Porphyry, they admit that sacred ceremonies can purify the spiritual or pneumatic soul but not its highest part, the intellectual soul; that they can raise it to the region of the stars but not bring it back to the Supreme Being. The late pagan philosophy asserts constantly and forcibly that the wise man’s reason is able by itself, or rather through a celestial grace, without the intervention of any liturgy, to ensure its own return to its divine source. “As,” says Porphyry, “he who is the priest of a particular god knows how to consecrate his statues, celebrate orgies, perform initiations and lustrations, so the true philosopher, who is the priest of the universal God, knows how to make His sacred images and to carry out His purifications and all the processes which will unite him to this God.”[292]