The history of Christian philosophy begins not with a Christian but with a Jew, Philo of Alexandria, elder contemporary of St Paul. He was born probably about 25 B.C. and was dead by a.d. 50. Unyielding in meticulous observance of the Mosaic law as the infallibly revealed will of God not only for the chosen people but also for Gentile proselytes (for whose edification some of his writing is directed), Philo is also fully hellenized, presenting a very Greek face to the world. Hebrew he knew imperfectly if at all. His Bible is the Greek Old Testament, in which the Pentateuch towers in authority above the rest; and his belief that the Septuagint translation was divinely inspired relieved him of any need or responsibility to refer to the original text.

Judaism had come into violent conflict with ‘Hellenism’ at the time of the Maccabean struggle which saved Israel from the destruction of its distinctiveness. Monotheistic Jews could never accept a syncretism which identified Yahweh with Zeus. Yet neither could they turn their back on Hellenism and devote themselves to their private pieties in a mood of nationalistic particularism. For Judaism was a missionary religion, and the ancient prophetic vision of Israel's call to be a light to lighten the Gentiles precluded isolationism, even if this had been a practical possibility, which it was not. The Jews were dispersed through the Mediterranean world. Their language and culture became Greek through and through, and well-to-do Jewish parents (like Philo's) provided their sons with a liberal education under Greek tutors.