Systematic and philosophic exposition of the tenets of Judaism by R. Saadiah ben Joseph Gaon (882-942), translated into Hebrew by R. Judah ben Saul ibn Tibbon. Saadiah states his purpose in writing Emunot ve-De'ot in the introduction, that is, he is responding to the moral, spiritual, and intellectual confusion of his age by providing a guide and inspiration to his people. There is an introduction from David Slutzki, a publisher and businessman who brought several works to press. R. Saadia writes, "I will begin this book . . . with an exposition of the reasons why men, in their search for truth, become involved in errors, and how these errors can be removed . . .; moreover, why some of these errors have such a powerful hold on some people so that they affirm them as the truth, deluding themselves that they know something." R. Saadiah firmly believes that philosophy and religion are not in contradiction, but rather are meant to help and supplement each other in finding and propagating truth. Both have a divine source and can not, therefore, teach anything that is incompatible with the other. Saadiah wrote Emunot ve-De’ot in 4633 (873) in Arabic and it was translated into Hebrew by Judah ben Saul ibn Tibbon in 4946 (1186). This volume is part two of the entire work. In the prologomen, Saadiah addresses doubt and belief, identifying three sources of knowledge: 1) sense-perception; 2) reason or intuitive, such as approval of truth and disapproval of falsehood; and 3) inferential or logically derived knowledge. In addition, for the Congregation of Believers in the unity of God there is a fourth source of knowledge, that is, the Bible and tradition. The book is divided into ten ma'amrim (chapters), that is, 1) on creation ex nihilo; 2) the unity of the Creator; 3) commandment and prohibition, that is, the precepts ordained by the creator; 4) obedience and disobedience, which encompasses human happiness; 5) merits and demerits, which encompasses free will; 6) the essence of the soul, death, and what follows it; 7) resurrection of the dead in the present world; 8) on the redemption of Israel; 9) reward and punishment in the future world; and 10) about that which is best for man to do in this world. This last ethical chapter is not a continuation of the previous chapters but an added ethical unit, offering practical advice.

Emunot ve-De'ot may have been written and issued by Saadiah in separate monographs, and combined by him later into an organic whole, suggested by references within the work to other parts. Several chapters have been printed independently and the entire work has been translated into a number of languages.

בסוף הספר: "ר' דוד סלוצקי... הגיע בהגהותיו ופירושיו... עד דף [צ"ל: עמ'] 87. קמתי אני תחתיו להגיה ולפרש את השארית... י' דינעס". (ספרי חכמת ישראל... נסדרו ונערכו עם הוספות... והוגהו... ע"י הוצאות שונות וכתבי יד עתיקים, ע"י דוד סלוצקי, חלק שני)