Hasdai Crescas

Hasdai Crescas was a Jewish philosopher, rabbi and communal leader in the Crown of Aragon, active in Barcelona and later Saragossa. In Or Adonai (Light of the Lord) he subjected Aristotelian physics, and the use Maimonides made of it, to sustained criticism. In particular he argued that an actual infinite is possible, which removes a premise of the standard proofs that the chain of causes must be finite, and he defended the possibility of void and of other worlds. His critique of Aristotle was later read with interest by Spinoza.

Key ideas

• An actual infinite is possible, so arguments for God that depend on the impossibility of an infinite series fail.
• Space can be an infinite void, against Aristotle's account of place.
• Human choices are causally determined, yet commandments and reward remain meaningful.
• God is better approached through love and joy than through the intellect alone.

Major works

• Or Adonai (Light of the Lord, completed 1410)
• Refutation of the Christian Principles (Bittul Iqqarei ha-Notzrim; written in Catalan, surviving in Hebrew translation)

In the conversation

• Question What was Hasdai Crescas’s case that an actual infinite is possible? Tal Rosen · 5 replies