Through Aristotle these doctrines were first introduced into Eastern Europe; indeed, eventually, as we shall see, he was regarded as the author of them.  They exerted a dominating influence in the later period of the Alexandrian school.  Philo, the Jew, who lived in the time of Caligula, based his philosophy on the theory of emanation.  Plotinus not only accepted that theory as applicable to the soul of man, but as affording an illustration of the nature of the Trinity.  For, as a beam of light emanates from the sun, and as warmth emanates from the beam when it touches material bodies, so from the Father the Son emanates, and thence the Holy Ghost.  From these views Plotinus derived a practical religious system, teaching the devout how to pass into a condition of ecstasy, a foretaste of absorption into the universal mundane soul.  In that condition the soul loses its individual consciousness.  In like manner Porphyry sought absorption in or union with God.  He was a Tyrian by birth, established a school at Rome, and wrote against Christianity; his treatise on that subject was answered by Eusebius and St. Jerome, but the Emperor Theodosius silenced it more effectually by causing all the copies to be burnt.  Porphyry bewails his own unworthiness, saying that he had been united to God in ecstasy but once in eighty-six years, whereas his master Plotinus had been so united six times in sixty years.  A complete system of theology, based on the theory of emanation, was constructed by Proclus, who speculated on the manner in which absorption takes place:  whether the soul is instantly reabsorbed and reunited in the moment of death, or whether it retains the sentiment of personality for a time, and subsides into complete reunion by successive steps.

Arabic psychology.  From the Alexandrian Greeks these ideas passed to the Saracen philosophers, who very soon after the capture of the great Egyptian city abandoned to the lower orders their anthropomorphic notions of the nature of God and the simulachral form of the spirit of man.  As Arabism developed itself into a distinct scientific system, the theories of emanation and absorption were among its characteristic features.  In this abandonment of vulgar Mohammedanism, the example of the Jews greatly assisted.  They, too, had given up the anthropomorphism of their ancestors; they had exchanged the God who of old lived behind the veil of the temple for an infinite Intelligence pervading the universe, and, avowing their inability to conceive that any thing which had on a sudden been called into existence should be capable of immortality, they affirmed that the soul of man is connected with a past of which there was no beginning,, and with a future to which there is no end.