Levi ben Gershom (Gersonides)

Levi ben Gershom (1288–1344), known as Gersonides, was a Jewish philosopher, Talmudist, mathematician, physician and astronomer born at Bagnols-sur-Cèze in Languedoc, who lived at Avignon and Orange. His masterwork The Wars of the Lord, written in 1317–1329, defended strict Aristotelian positions and surveyed Arabic astronomy; part of it was translated into Latin for Pope Clement VI in 1342.

He is credited with inventing the Jacob's staff to measure stellar angles, used the camera obscura for eclipse observations, and pioneered mathematical induction. He died on 20 April 1344.