BRETHREN OF SINCERITY, EPISTLES OF

BRETHREN OF SINCERITY, EPISTLES OF (Arab. Ikhwān al-ṯafā'), series of Arabic treatises ostensibly covering the spectrum of philosophic studies: mathematics and logic, the natural sciences, metaphysics, and the political and religious organization of society including a discussion of the nature and organization of the "Sincere Brethren." The authors of the work were a group of people belonging to the class of government secretaries and men of letters in 10th-century baghdad . They were connected with the Ismāʿīliyya movement which opposed the claims of the reigning abbasid caliphs. Their treatises or epistles no doubt also served to propagate their political and religious ideas under the cloak of a philosophic encyclopedia. The level of learning set forth in the encyclopedia is popular and its philosophy is essentially neoplatonic, in contradistinction to the purer Aristotelianism preferred by, e.g., al-Fārābī . Their writings seem to have influenced a number of Jewish philosophers, notably Joseph ibn Ẓaddik and solomon ibn gabirol as well as moses ibn ezra . shem tov ibn falaquera translated excerpts from their writings in his Sefer ha-Mevakkesh (1778). In Arles (1316) kalonymus b. kalonymus translated a treatise of the Epistles into Hebrew under the title Iggeret Baʿalei Ḥayyim ("The Epistle of the Animals"). It has been printed a number of times and the Hebrew version has been translated into Yiddish and Ladino.   -BIBLIOGRAPHY: Steinschneider, Uebersetzungen, 860–2; D. Kaufmann, Geschichte der Attributenlehre (1877, repr. 1967); Vajda, in: Archives d'histoire doctrinale et littéraire du moyen-âge, 24 (1949), 114 and passim; Stern, in: Islamic Studies, 3 (1964), 405–28. ADD. BIBLIOGRAPHY: "Ikhwān al-Ṣafā'," in: EIS2, 3, S.V. (incl. bibl.). (Lawrence V. Berman)