Hasdai Crescas

Hasdai Crescas originated from Catalonia. He earned a reputation for his knowledge of Talmudic law, and was a rigid critic of Aristotelian thinking (especially Moses Maimonides), in favour of Jewish doctrine and philosophy. See: Wolfson, 1929; CCS, pp. 77–8; Lagerlund, 2011, vol. 1, pp. 454–6. See: https://plato.stanford.edu/entries/crescas/.

In the concluding portion of Spinoza's letter to Lodewijk Meyer of April 20, Spinoza discusses the indivisibility of infinite extension. In that context, he puts forward a critical commentary on a large citation from a work by ‘a certain Jew, called Rab Chasdai’, which deals with the demonstration of the existence of God. The reference made is to the first book of Or Adonai or Or Hashem (Light of the Lord), which was written by Crescas. Against Aristotle, who banned the concept that the existence of a first cause can be conceived by actual infinity (Aristotle, Metaphysics, a 2 (994a)), Crescas argues in favour for an ‘uncaused’ being necessary of existence, i.e., God. According to his modal argument, the concept of eternity is not contradictory by itself and proves that an infinite series of worldly causes and effects is possible, regardless whether these were considered finite or infinite (cf. Melamed, 2004, p. 207). For Crescas, this indicates that for him there is a reason for the existence of any being (Ibid., p. 2010). Spinoza approvingly endorses Crescas’s argument on actual infinity, but stresses his own stand of self-caused necessary substance (not sine causa, but causa sui) (cf. Lærke, 2013, pp. 59-65).