Rabbi Hasdai Crescas, who led the Jewish community in fourteenth- and early fifteenthcentury Aragon, was revered as a great rabbinic authority. He wrote a philosophical polemic refuting Christian principles and, more importantly, Or Adonai (also known as Or Hashem or The Light of the Lord), a philosophical rebuttal of Aristotelian rationalism in the theology of Maimonides and Gersonides. Or Adonai is, in effect, a critique of Aristotelian rationalism itself and, as such, anticipates the seventeenth-century work of Baruch Spinoza, who was influenced by the example of Crescas.
Crescas used Neoplatonic idealism as a counter to Aristotle, arguing that rationalism is inadequate to understanding the world. In the course of the critique, Crescas provided a definition of the infinite in terms of both logical and mathematical principles, a definition of matter, a definition of place, a discussion of free will, and a platonic discourse on the essence of the soul and its status in the afterlife. All contribute to his defense of traditional Jewish theology.
Hasdai Crescas was born about 1340 in Barcelona into a family of merchants and rabbis. He became a renowned Talmudist before leaving Barcelona to accept the office of crown rabbi of Aragon. He became a teacher—his most famous student was the philosopher Joseph Albo—and despite his political prominence was imprisoned on a false charge of host desecration in 1378. In 1391, his only son was killed an anti-Semitic massacre in Barcelona. Revered as the spiritual head of Spanish Jewry, he died at the end of 1410 or in January of 1411.
