(c. 1340-c. 1410). Spanish Jewish philosopher and communal leader (Crown Rabbi of Aragon). In 1383, he was one of several delegates of Catalonian Jewry who secured the renewal of Jewish rights from the king of Aragon. Despite his close association with the court of Aragon, his son suffered martyrdom in the 1391 anti-Jewish massacres in Barcelona. Crescas' fame rests on his place in medieval Jewish philosophy. Of his two important works, the first, written in Spanish (1397), was translated into Hebrew by Joseph Ibn Shem Tov under the title Bittul Ikarei ha-Notzerim (1451), "A Refutation of the Principles of the Christians," being a spirited criticism of Christian dogma, notably the dogma of the Trinity. Crescas' motives were to help maintain the loyalty of Jews to Judaism and to win back Jewish apostates at a time when the influence of the Church was becoming increasingly more powerful.
His other work, written in Hebrew, is Or Adonai ("The Light of the Lord," 1410), the primary aim of which is to present a systematic exposition of the Jewish faith, its principles, beliefs, and opinions. In much of his treatment, Crescas seeks to refute the philosophy of Maimonides. He is critical of Maimonides' formulation of basic Jewish beliefs and formulates his own principles which he divides into a number of groups. First is the basic belief in the existence, unity, and incorporeality of God. He then lists those fundamentals without which Judaism could not exist, concerning certain attributes of God, the nature of prophecy, and the Torah. Crescas then turns to what he calls "true opinions." Anyone who disbelieves them is a heretic, but it is nevertheless conceivable to be a Jew without holding to these opinions. These include Creation, Immortality and Resurrection, Reward and Punishment, the Messiah, and the efficacy of Prayer. Finally, there are beliefs which are only "probabilities" and which, while Crescas holds them to be correct, are nevertheless of such a nature as to allow for different opinions. Whoever does not believe in them is not to be censured, although he is in error. These "probabilities" relate to such matters as the power of the stars and the existence of demons.
Crescas is the only medieval Jewish philosopher of note who seems to set limits to human freedom in order to preserve the belief in God's foreknowledge of events. He reconciled this qualified determinism with his belief in reward and punishment by making a clear distinction between determinism and fatalism (see Free Will; Predestination); it is only the latter concept that has no room for human effort, with the resultant reward or punishment. Unlike Maimonides, Crescas rejected the idea that only the intellectual soul is immortal. Every soul, he argued, is an eternal substance and there is soul life, of one kind or another, for each individual soul. Crescas' Or Adonai influenced later philosophers, and Spinoza's treatment of freedom and necessity owes much to Crescas.
