For a long time the Jews had taken no part in the development of Hellenistic philosophy, although in the latter Syriac period they had participated in medical studies and in natural science, of which we have seen evidence in the important work of Jewish physicians and scientists at Baghdad under al-Ma´mun and the early `Abbasids. Outside medicine and natural science Jewish interest seems to have been mainly confined to Biblical exegesis, tradition, and canon law. One of the few exceptions to this restriction of interests was _Sa`id al-Fayyumi_ or Saadya ben Joseph (d. 331 A.H. = 942 A.D.), a native of Upper Egypt, who became one of the Geonim of the academy at Sora on the Euphrates, and is best known as the translator of the Old Testament into Arabic, which had now replaced Aramaic as the speech of the Jews both in Asia and in Spain. As an author his most important work was the _Kitab al-Amanat wa-l-´Itiqadat_, or “Book of the articles of faith and dogmatics,” which was finished in 321-2 (= A.D. 933), and was afterwards translated into Hebrew as _Sefer Emunot we-De´ot_ by Judah b. Tibbon. He was the author also of a commentary on the Pentateuch, of which only a portion (on Exod. 30, 11-16) survives, as well as other works; but it is in the first-named and in the commentary that his views appear most clearly. For the first time a Jewish writer shows familiarity with the problems raised by the Mu`tazilites, and gives these a serious attention from the Jewish stand-point. It does not seem, however, that we should class Sa`id as a Mu`tazilite; he more properly represents the movement which produced his Muslim contemporaries, al-Ash`ari and al-Mataridi, that is to say, he is one of those who use orthodox _kalam_ and adapt philosophy to apologetic purposes. His position is shown most clearly in the “Book of the articles of faith and dogmatics” in dealing with the three problems of (_a_) creation, (_b_) the Divine Unity, and (_c_) free will. In the first of these he defends the doctrine of a creation _ex nihilo_, but in giving proofs of the necessity of a creator he shows in three out of the four arguments employed distinct traces of Aristotelian influences. In treating the doctrine of the Divine Unity he is chiefly concerned with opposing the Christian teaching of the Trinity, but incidentally is compelled to deal with the idea of God and the Divine attributes, and in doing so maintains that none of the Aristotelian categories can be applied to God. As to the human will he defends its freedom, and his task is mainly an effort to reconcile this with the omnipotence and omniscience of God. In the fragment on Exodus he refers to the commands of revelation and the commands of reason, these latter, he asserts, being based on philosophical speculation.