The exalted Hebrew idea of God was still too
sublime for the pagan nations, even for their philosophers. The world
in truth was decaying morally and intellectually, and most of all in
powers of imagination; and its hunger for God found expression in
crude and stunted conceptions of His nature. Unable any longer to soar
to Heaven, it sullied the majesty of the Deity, and divided the
Godhead in order to bridge the gap. Numenius represents in philosophy
the Gnostic ideas about God which were widely held by the heretics,
Jewish and Christian, of the second century. He divides the Godhead
into two separate powers: (1) the impersonal Being behind all reality,
free from all activity whatsoever; (2) the Demiurge or active governor
of the universe, who again is subdivided into a transcendent and an
immanent power.

The teaching of Plotinus, the most famous of the later Alexandrian
neo-Platonists, shows a further step in the development of religious
Platonism. Viewed from its higher side it is an attempt to explain
everything as the emanation of the One. But philosophy in the third
century debased itself in order to support the tottering polytheistic
religion of the pagan world against the modified Hebraic creed,
Christianity, which was fast demolishing its power. Against the
Trinity of the Church the philosophers set up a heavenly Trinity of
so-called reason: the Ineffable One, the Demiurgic Mind, and the World
Soul; and between this Trinity and man they placed intermediate
hierarchies of gods, angels, and demons--in fact, the whole fugitive
army of Greek polytheism thinly disguised. All the vulgar fancies and
superstitions which Philo had intellectualized, these later Eastern
Platonists sought to revive and justify by conceptions of physical
emanation blended of false science and mysticism. They hoped to found
a universal religion by finding room in one system for the deities of
all nations!

From Plotinus down to Proclus, neo-Platonism became more
unintellectual, more insane, more pagan, and, finally, with its vapid
dreams, it brought the history of Greek philosophy to an inglorious
close. Its finer teachings, however, deeply affected mediaeval
philosophy, and not least the Arab-Jewish school. The theory of
emanations and spiritual hierarchies pervades the writings of Ibn
Ezra, Ibn Gabirol, and Ibn Daud, and thus indirectly provides a
connection between the culture of Alexandrian Judaism and the culture
of Spanish Judaism.