From the period of the New Academy the decline of Greek philosophy was uninterrupted. Inventive genius no longer existed; its place was occupied by the commentator. Instead of troubling themselves with inquiries after absolute truth, philosophers sought support in the opinions of the ancient times, and the real or imputed views of Pythagoras, Plato, or Aristotle were received as a criterion. In this, the old age of philosophy, men began to act as though there had never been such things as original investigation and discovery among the human race, and that whatever truth there was in the world was not the product of thought, but the remains of an ancient and now all but forgotten revelation from heaven--forgotten through the guilt and fall of man. There is something very melancholy in this total cessation of inquiry. The mental impetus, which one would have expected to continue for a season by reason of the momentum that had been gathered in so many ages, seems to have been all at once abruptly lost. So complete a pause is surprising: the arrow still flies on after it has parted from the bow; the potter's wheel runs round though all the vessels are finished. In producing this sudden stoppage, the policy of the early Cæsars greatly assisted. The principle of liberty of thought, which the very existence of the divers philosophical schools necessarily implied, was too liable to make itself manifest in aspirations for political liberty. While through the emperors the schools of Greece, of Alexandria, and Rome were depressed from that supremacy to which they might have aspired, and those of the provinces, as Marseilles and Rhodes, were relatively exalted, the former, in a silent and private way, were commencing those rivalries, the forerunners of the great theological struggles between them in after ages for political power. Christianity in its dawn was attended by a general belief that in the East there had been preserved a purer recollection of the ancient revelation, and that hence from that quarter the light would presently shine forth. Under the favouring influence of such an expectation, Orientalism, to which, as we have seen, Grecian thought had spontaneously arrived, was greatly re-enforced. [Sidenote: Philo the Jew thinks he is inspired.] [Sidenote: His mystical philosophy.]