Greco-Jewish philosophy may be described as an effort to harmonize the
sacred books of the Hebrews with the tenets of Greek philosophy. The
Jews of Alexandria were steadfast in the belief that their sacred books
contained wisdom infinitely superior to the wisdom of philosophers, yet
they could neither resist the inroad of Greek culture and Greek
philosophy nor refrain from admiring the wisdom of the Greeks. They set
themselves, therefore, the task of finding Plato in the law and of
finding the law in Plato, being guided in the accomplishment of this
purpose by some such principles as the following:
1. Revelation is the highest possible philosophy: it includes what is
best in Greek philosophy.
2. The Greeks derived their doctrines ultimately from the Jewish
Scriptures, or at least from Jewish tradition.
3. "The difference between the revealed doctrines of the Jews and the
philosophy of the Greeks consists chiefly in this, that in the sacred
books of the Jews truth is expressed in symbols and figures, whereas
Greek philosophy puts the figure aside and sets before us the thought
which the figure expressed." 
 Stöckl, Lehrbuck der Geschichte der Philosophie
(Münster, 1870; Mainz, 1888). I, 183; English trans. (Dublin,
1887), p. 161.
The practical conclusion of all this was the adoption by the
Alexandrian Jews of the allegorical method of interpretation.
Aristobulus (about 160 B.C.) was the first to apply these
exegetical principles in a treatise of which some fragments are
preserved by Eusebius.  The first to build on them a system of
thought was Philo of Alexandria.
 Pr. Ev., VII, 14, etc.
Life. Philo was an Alexandrian Jew. Little is known of his life
beyond the fact that in A.D. 40 he was sent to Rome to represent his
co-religionists in their contest with Apion.
Sources. Philo's works, composed in Greek, are very voluminous.
Besides these writings we have as sources of information the references
which Eusebius, and other writers of the early Church make to the
teachings of Philo. 
 For bibliography, cf. Ritter and Preller, op. cit.,
p. 489; Suidas, op. cit., art Philon.
General Aim of Philo's Philosophy. It was Philo's aim so to
expound the Scriptures as to bring the revealed religion of the Old
Testament into agreement with the philosophy of the Greeks and
especially with Platonism, Aristotelianism, and Stoicism; for to each
of these systems he had recourse according as each in turn seemed best
suited to the text under consideration. On account of this mixture of
different elements it is impossible to find harmony or unity in his
God, the first cause, is the starting point of Philo's system. He is
above all created things. From His works we know that He exists, but
what He is is above our comprehension; He transcends all predicates,
except the predicate of Being, ho on, which He applied to
Himself: "I am who am." Nevertheless, since men will speak of God after
their own fashion, He is called One, Unbegotten, Unchangeable, Free,
Independent of all things. 
 For authorities, cf. Ritter and Preller, op. cit.,
pp. 491 ff.
The World. The Stoics taught that the world is God: Philo
teaches that it is the work of God. It is not eternal; it was made, in
time, by God, who wished, by creating, to manifest His goodness. God,
being supremely immaterial, did not create the world by His own
immediate action; He had recourse to the intermediate agency of certain
powers (dunameis), which are described at one time as
Divine Ideas and at another as agents,
souls, angels, and demons. All these powers are comprehended in the
The Logos. This is one of the peculiar tenets of Philo's
philosophy. Philo might have taken the Platonic term Idea to
designate the Logos, for his notion of the Logos is more akin to the
Platonic world of Ideas than to any other notion in Greek philosophy.
He chose the word Logos, however, because of the biblical use of
the term in the expression "Word of God," and because of the Stoic use
of it in the phrase logos spermatikos. Indeed, the Logos in
Philo's philosophy corresponds to the Stoic concept of a world-soul as
well as to the Platonic world of Ideas; for just as in man there are
the extrinsic word and the indwelling reason, so in the
Divine Logos we may consider the logos endiathetos, or aggregate
of Ideas in the divine mind, which is divine wisdom, and the logos
prophorikos, or world-soul, which is divine power pervading all
things and giving life to all.
The Logos, then, is the first begotten of God, the Son of God, a
God, but not God Himself. Its principal function is that of
mediation: like the high priest, it stands between the Creator and
the creature. Philo, however, fails to determine in any definite manner
what the Logos is in itself: the obscurity, the vacillation, the
apparent contradiction of the expressions which he employs, show how
vague is his concept of the nature of the Logos, although he has a
definite concept of its function.
Anthropology. In his doctrine concerning man Philo distinguishes
the ideal man, made to the image and likeness of God, and the man of
our own experience, in whom he makes a further distinction of rational
and irrational natures. At times he elaborates this distinction still
further, teaching that there are eight different natures in man. In
speaking of the rational soul, he renews the Pythagorean doctrine of
transmigration, the Stoic doctrine of the kinship of the soul to God,
and the Platonic doctrine of the soul's preexistence. The soul of man
does not differ from the angelic nature, In punishment for some
original sin it was degraded to a union with the body, which is its prison, its
grave, the source of all its ills and all its misery.
Theory of Knowledge. Philo distinguishes three faculties of
Cognition aisthêsis, which has for its object the concrete
and sensible; logos, which is the reasoning faculty; and
Nous, which is the faculty of immediate contemplation of
intellectual truths. Contemplation, then, is the highest kind of
knowledge; by it only can man attain absolute certainty. It is not,
however, like reason and sense, dependent on the natural powers of the
mind; its light is a light from above, an illumination which God alone
can give, and which He gives through the Logos to those who pray for
it. This doctrine of mystical illumination leads to the ethical
doctrine of mystical ecstasy.
Ethics. The body is constantly inclining the soul towards sin.
Man's first duty is, therefore, to free his soul from the trammels of
the body, to rise above the world of sense, to acquire the
apathy which the Stoics inculcated. His next duty is to rise
from reason to contemplation, until the soul at last becomes one with
the Divine Wisdom, and man and God become united in mystical
ecstasy. In this ecstatic union consists the supreme happiness of
man. Philo, true to his Oriental instinct, places contemplation above
action; above the cardinal virtues, which belong to the active life, he
places confidence in God, piety, penance, and contemplative wisdom. The
possessor of this wisdom, the truly wise, is truly free: wisdom rescues
him from the dominion of matter.
Historical Position. Despite the inconsistency of many of his
doctrines, Philo exercised a considerable influence not merely on the
Gnostics of the first centuries of the Church but also on the Jewish
opponents of Scholasticism during the Middle Ages. The most
characteristic qualities of his philosophy are its spirit of mysticism,
its ethical quietism, and its psychological and ethical dualism --
the separation of body and soul, the sources of evil and of good in