ABSTRACT
Saadiah ben Joseph was the earliest philosopher of the medieval period. Born in Pithom in the Fayim district of Egypt, he settled in Babylonia in 921. In 928 he became gaon of Sura and wrote studies on various subjects including Hebrew philology, Jewish liturgy and halakhah. In addition he produced the first theological treatise of the Middle Ages, The Book of Beliefs and Opinions. In this work Saadiah countered the religious beliefs of Christians, Muslims and Zoroastrians. Basing his arguments on the kalam (teachings of the Muslim schools), he insisted that there are four sources of knowledge: sense experience, intuition of self-evident truths, logical inference and reliable tradition. The last source (derived from the first three) is the basis of civilization. Of divine origin, it provides guidance and protection against uncertainty.
