Byzantine philosopher and humanist; b. Southern Italy, c. 1025; d. after 1082. A student at Constantinople under Michael Psellus (c. 1049), he succeeded his master at the university there early in 1055 and became a close friend of Emperor michael vii ducas. He reached the height of his career in the 1070s, but his popularity as a teacher earned him many enemies, particularly among the Byzantine clergy. His lectures dealt with the teachings of Plato and the Neoplatonists, and he wrote commentaries on Plato, on Aristotle's logic, on Proclus, and on iamblichus. In 1077 nine theses reputed to be taken from his teachings were condemned by a synod in Constantinople. Finally, on March 13, 1082, Italus and his doctrines were solemnly condemned by a second synod, and he was banished to a monastery when the sentence was confirmed by Emperor Alexius I Comnenus (March 20). Most modern scholars believe that he was not guilty of doctrinal error, but that it was his devotion to Platonic philosophy and his overemphasis in the employment of logic and reason to explain dogma that brought down the wrath of the Church upon him. Although his works were publicly burned, some MSS are still extant.
Bibliography: Opuscula selecta, ed. g. cereteli (Tiflis 1924–26). Quaestiones quodlibetales, ed. p. joannou (Ettal 1956). p. stephanou, Jean Italos, philosophe et humaniste (Orientalia Christiana Analecta 134; 1949). Lexikon für Theologie und Kirche, ed. j. hofer and k. rahner, 5:1043. v. grumel, Les Regestes des actes du patriarcat de Constantinople (Kadikoi-Bucharest 1935—) 1.3:907, list of theses condemned in 1077. p. joannou, Die Illuminationslehre des Michael Psellos und Joannes Italos (Ettal 1956). f. masai, Pléthon et le platonisme de Mistra (Paris 1956) 284–297.
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