Foremost medieval spiritual leader, Talmudist, biblical exegete, and philosopher (882–942). Saadiah was born in Egypt, and lived for a time in Tiberias, after which he was appointed by the exilarch, David ben Zakkai, to be the head of the college at Sura in Babylon, hence the title Saadiah Gaon (see GEONIM). But rulers seem to have a habit of falling out with their protégés and David soon deposed Saadiah. The quarrel between the two lasted for seven years, remaining unresolved until Saadiah was reinstated. Saadiah, responding to the Karaite interest in the Bible, wrote a translation of the Bible into Arabic, in which he displays his virtuosity as a grammarian and philologist as well as his vast knowledge of the Jewish traditional sources. His Prayer Book was one of the earliest to be compiled and is more comprehensive than those of his very few predecessors. But Saadiah's fame rests on his philosophical work, Emunot Ve-Deot (Beliefs and Opinions), written in Arabic and translated into Hebrew by Judah Ibn Tibbon. This work is the first systematic Jewish theology. It has a special significance as a philosophical defence of Rabbinic Judaism by the leading representative of that Judaism of his day.
The ‘beliefs’ in the title are the postulates of the Jewish religion, while ‘opinions’ are the truths arrived at by empirical investigation and rational reflection. Saadiah takes issue with those who see philosophy as harmful to faith. On the contrary, faith is strengthened when supported by reason. Influenced strongly by the thought of the Arabic thinkers who sought in similar fashion to reconcile Islam with philosophical enquiry, Saadiah holds that there are two ways to religious truth, reason (see RATIONALISM) and revelation (of the Torah, for Saadiah). Both ways are essential: reason because without it superstitious ideas will proliferate; revelation because not everyone can arrive at the truth by speculation. Saadiah's famous illustration is of the man who is told that a heap of coins contains a certain number of coins. He may not have the time to count them and will then have to rely on those who have told him the number of the coins. But, if he counts the coins, he will know how many there are with a certainty he would not otherwise have had. Saadiah thus proceeds to prove by reason the existence of God, relying chiefly on the cosmological proof. The world could not have created itself since it is a logical absurdity for anything to cause itself. God is the uncaused Cause of the universe but His nature is beyond human comprehension.