This guiding principle determines Philo’s attitude to knowledge, involving, as it does, that we only know by Divine inspiration, or, as he says, by the immanence of the Logoi.[261] The possibility of knowledge was one of the burning questions of the age, and it was the failure of the old dogmatic schools to answer it which led to a great religious movement in Greek philosophy.  How can man attain to true knowledge, it was asked, about the universe, seeing that perceptions vary with each individual, and of conceptions we have no certain standard?  The old Hebrew attitude to this question is expressed by the verse of the Psalmist:  “The heavens are the heavens of the Lord, but the earth hath He given to the sons of men” (Psalm cxv), which implies that man must not try to penetrate the secrets of the universe.  Philo is sufficiently a philosopher to desire knowledge about things Divine and human, but at the same time he has a complete distrust in the powers of human sense and human reason.  About the physical universe he is frankly a skeptic,[262] but his religious faith leads him to hold that God vouchsafes to man some knowledge of Himself and of the proper way of life, i.e., ethics.  “Man knows all things in God."[363] Plato similarly had despaired of knowledge of the physical world, and had turned to the heavenly ideas as the true object of thought.  Moreover, in his early period, while his theory was still poetical and mystical, he had conceived that knowledge was made possible in the subject, by the entrance of “forms,” or emanations, from the ideas.  This theory Philo adapts to his Jewish outlook.  Like Plato, he turns away from the physical to the ideal world,[264] and he regards the ideas of wisdom, virtue, bravery, etc., which are theologically powers of God, as continually sending forth Logoi, forms or forces (the angels of popular belief), to inform and enlighten our minds.  Throughout, God is the cause of all knowledge as well as of being, for these effluences are but an expression of God’s activity.  In Philo’s theory, object and subject are really one.  What can be known are the modes or attributes of God, which philosophically are “Ideas”; what knows is the emanation of the Idea, which God sends into the human soul that is prepared to receive it by pious contemplation.  “Through the heavenly Wisdom, wisdom is seen, for wisdom sees itself.”  “Through God, God is known, for He is His own light."[265]

Thus all knowledge is intuition, and man’s function is not so much to reason as to lead a life of piety and contemplate the Divine work in the hope of being blessed with inspiration.  It would be a mistake, however, to take Philo’s words quite literally.  He does not deny the need of human effort and striving for knowledge; for the Divine influence is not vouchsafed till we have prepared for it and consecrated all our faculties to God.  But, devout mystic as he is, he ascribes every consummation to the direct help of