The Spanish rabbi and philosopher Hasdai Crescas was born in Barcelona, the scion of a distinguished family. He exercised considerable influence both in the Jewish community and at the Aragonese court. After the 1391 persecution of the Jews, in which his only son perished, Crescas moved to Saragossa, where he engaged in literary activity until his death.

Crescas's purpose was to defend Judaism from both internal and external subversion. To this end he composed his Spanish "Refutation of the Principles of Christianity" (extant only in Hebrew translation), a rational critique of Christian dogmatic theology, and his masterwork, The Light of the Lord (Or Adonai), conceived as an introduction to a legal code that was never composed. Crescas wrote in the tradition of those thinkers, such as Judah Halevi and Nahmanides, who rejected the rationalistic compromising of Judaism with the teachings of Aristotle, but he differed...