The first significant Jewish philosopher is recognized as Philo (ca 13 BC - 45/50 AD), who lived in Alexandria, Egypt. His biblical commentaries (written in Greek) powerfully influenced Christian philosophy; in fact, Philo is considered the forerunner of "biblical exegesis," a Christian tradition of critically explaining and interpreting scripture. Philo said the lower, literal level of interpretation applies to the perfection of the body, while the higher allegorical or symbolic level applies to the perfection of the soul.
Sa'adia ben Joseph al-Fayyumi (892-942) preserved and enlivened a dying Jewish tradition by translating the Hebrew Bible (The Torah) into Arabic. He wrote polemics in response to sectarian Jews; pedagogical works as head of the Academy in Sura, Babylonia; and philosophical works, including The Book of Doctrines and Beliefs. Sa'adia argued that the four roots of knowledge are the senses, reason, inference, and reliable tradition, and he said there can be no real conflict between reason and revelation. Sa'adia wrote that complete or reliable knowledge of the divine is not available to humans, so we must rely on speculative inquiry about the highest and most valuable aspects of knowledge.
Moses ben Maimon (1138-1204), popularly known as Maimonides, was a physician, jurist, philosopher and spiritual authority for exiled Jewish communities. Maimonides believed that the prophets were most perfectly knowledgeable, but he also admired Aristotle and the Islamic philosopher al-Farabi. He insisted that God is a perfect, incorporeal unity that has no attributes atall; to speak of God's characteristics, features, or attributes is idolatry. Humans cannot know what God is; we can only know what God is not, and that there is a radical distinction between God and human beings. Maimonides defended a theory of creation ex nihilo (or "out of nothing"), arguing that a provident, omniscient God uniquely created "first matter." Maimonides associated eternity and immortality with permanent intellect, which he said is perfectible when unconstrained by human mortality.