The ArgumentLevi ben Gerson, also known as Gersonides or Leo de Balneolis, was one of the most original Jewish thinkers of the Middle Ages, and he wrote on logic, philosophy, biblical exegesis, mathematics, and astronomy. During the last years of his life he maintained relations with the papal court of Clement VI (1342–52) at Avignon, and collaborated in the translation into Latin of hisSefer Tekhuna(Book of Astronomy). The object of this paper is to establish the main stages of the redaction (...) of the Hebrew and Latin extant versions of his astronomical work. Although Levi declares that the work was finished in 1328,1 argue that this text was the preliminary draft of the preserved one, most of which was composed after 1338. A thorough revision of the work was undertaken at an indeterminate date before 1344. It is also argued that the final form of the work was probably due to the request of solar and lunar tables made to Levi by “great and noble Christians” around 1332. (shrink)

Gersonides has at times been viewed as an essentially orthodox Aristotelian in his metaphysical views. This designation, however, has been challenged on a number of grounds. This paper examines the way in which Gersonides revises the traditional conception of hylomorphism by positing that matter can exist without form. Motivated by a desire to reconcile Aristotelian natural philosophy with the Ptolemaic astronomical model, formless matter is seen as a necessary entity to posit in order for his cosmological model to be coherent. (...) By allowing for this exception case, Gersonides turns hylomorphism from a metaphysical principle to a general, though not universal, principle of physics that can must be revised if other observational and philosophical commitments are to be maintained, which speaks to a distinct attitude toward Aristotelian metaphysics than is otherwise assumed to be the case for Gersonides and his contemporaries. (shrink)