SEFER HA-EMUNOT VE-HA-DE‘OT (BOOK OF DOCTRINES AND OPINIONS), RABBI SAADIAH GAON, TRANSLATED BY RABBI JUDAH IBN TIBBON, CONSTANTINOPLE: SOLOMON BEN ISAAC JABEZ, 1562

The first edition of a fundamental work of Jewish philosophy. 

The author of this rare philosophical treatise, Rabbi Saadiah Gaon (Rasag; 882-942), was an important leader of Babylonian Jewry and the greatest Jewish scholar and author of the geonic period. Originally written in Judeo-Arabic, this book was translated into Hebrew by the twelfth-century Spanish scholar Rabbi Judah Ibn Tibbon under the title Sefer ha-emunot ve-ha-de‘ot. It is the earliest work of medieval Jewish philosophy to have survived intact.

After a general presentation of the causes of infidelity and the essence of belief, Rasag describes the three natural sources of knowledge – the perceptions of the senses, the light of reason, and logical necessity – as well as the fourth source of knowledge possessed by those who fear God: the “veritable revelation” contained in the Scriptures. He demonstrates that a belief in the teachings of revelation does not preclude an independent search for knowledge, but rather that speculation on religious subjects endeavors to prove the truth of the teachings received from the prophets and to refute attacks upon revealed doctrine, which must be raised by philosophic investigation to the plane of actual knowledge.

In the scheme of his work, Rasag closely followed the philosophical school of the Mu‘tazilites (the rationalistic dogmatists of Islam, to whom he also owed in part his thesis and arguments), but it is evident that he was influenced as well by Aristotelianism, Platonism, and Stoicism. He, in turn, influenced Jewish Neoplatonists, such as Rabbis Bahya Ibn Paquda (see lot 228), Moses Ibn Ezra, and Abraham Ibn Ezra. The impact of Rasag declined with the appearance of the Moreh nevukhim (see lot 22), in which Maimonides attacks this philosophical approach, alluding to Rasag although never mentioning him by name. In the fourteenth and fifteenth centuries, however, Maimonides’ philosophical opponents drew upon Rasag’s work. Sefer ha-emunot ve-ha-de‘ot has remained influential down to the present day.