ISAAC ISRAELI

Son of Solomon, Jewish physician and philosopher, also known as Isaac Judaeus; d. c. 932. Isaac was a native of Egypt who emigrated to Qayrawān (in modern Tunisia) about 907 and became a physician to the Fatimid Caliph ‘Ubayd Allah al-Mahdi. According to some authorities he died shortly before 932, but other accounts (of doubtful authority) imply that he was alive at later dates. His medical treatises, e.g., the Book of Fevers, the Book of Urine, the Book of Foodstuffs and Drugs, all written in Arabic, were long considered classics, and translated into Hebrew and Latin, giving their author fame among Muslims, Jews, and Christians. His medical reputation was somewhat overshadowed in the West by his Latin translator, constantine the african. Constantine's work, completed by 1087, best described as a paraphrase of Isaac's writings, received wide currency in medieval schools of medicine, as attested by surviving MSS.

As a philosopher, Isaac's inspiration was mainly Neoplatonic. The writings of the Muslim philosopher al-kindĪ abŪ yŪsuf and a Neoplatonic treatise ascribed to Aristotle (Ibn Hasday's Neoplatonist ) were the main influences on his philosophy. His writings in this field assumed the form of short treatises in Arabic: the Book of Definitions (Latin translation by Gerard of Cremona, two Hebrew translations); the Book of Substances, extant in fragmentary form; the Book on Spirit and Soul, in which Neoplatonic psychology is given Biblical foundation; a text known as Chapter on the Elements (in Hebrew translation only); and a somewhat longer treatise, Book of the Elements (extant in a Latin version by Gerard of Cremona, and two Hebrew versions). Whereas among the Muslim philosophers Israeli had no influence, his work seems to have been generally known among the Jewish Neoplatonists of Spain, although a more strictly Aristotelian philosopher of the rank of maimonides had naturally little sympathy with Israeli's somewhat primitive Neoplatonism. The texts available in Latin were used by schoolmen such as dominic gundisalvi, albert the great, and thomas aquinas.

Bibliography: Omnia Opera Ysaac (Lyons 1515). m. steinschneider, Die hebräischen Übersetzungen des Mittelalters (Berlin 1893); Die arabische Literatur der Juden (Frankfurt A. M.1902). c. brockelmann, Geschichte der arabischen Literatur, 3v. (Leiden 1937–42). g. sarton, Introduction to the History of Science (Baltimore 1927–48) v.1. a. altmann and s. m. stern, Isaac Israeli: A Neoplatonic Philosopher of the Early Tenth Century (London 1958). j. schmid, Lexikon für Theologie und Kirche, ed. j. hofer and k. rahner (Freiberg 1957–65) 5:773.

[s. m. stern]