Joseph Albo c. 1380 – 1444

Joseph Albo was a Spanish Jewish philosopher and the author of the Sefer ha-Ikkarim, the Book of Principles, the most widely read Jewish philosophical work in Iberia in the generation before the expulsion. Drawing on Maimonides, Crescas, and his teacher Hasdai Crescas, he organized Jewish religious belief around three roots: the existence of God, revelation, and reward. He participated as a representative of his community in the disputation of Tortosa in 1413, one of the major forced public debates of the late medieval Iberian Jewish experience.

Joseph Albo was born around 1380 in the Christian kingdom of Aragon, almost certainly at Monreal del Campo, where his family was settled. He studied with Hasdai Crescas, the leading Jewish philosopher of Spanish Jewry, and made his early reputation as a preacher and physician at Daroca. The forced disputation convened by the antipope Benedict XIII at Tortosa from 1413 to 1414 — a year-and-a-half-long debate intended to secure mass conversions — placed him among the small number of rabbinical defenders.

His major work is the Sefer ha-Ikkarim (Book of Principles), in four treatises, completed in 1425. Albo reduces the principles of Judaism — and, with appropriate modifications, of revealed religion as such — to three fundamentals (existence of God, revelation, and reward and punishment), develops eight derivative articles, and carries on a sustained polemic with Christian theology while drawing freely on its philosophical resources, particularly Aquinas. The work was widely studied in early modern Jewish learning and printed repeatedly.

Albo's flexible doctrinal minimalism, his philosophical treatment of the relations of natural law, conventional law, and divine law, and his careful stance toward the Christian-Jewish disputational literature made the Book of Principles one of the most-read works of late medieval Jewish philosophy. He died at Soria in 1444.