ר׳ לוי בן גרשון

ר׳ לוי בן גרשון (1288–1344), known as Gersonides or the רלב״ג, was a Provençal biblical exegete, philosopher, mathematician, astronomer, and halakhic scholar. Probably born at Bagnols-sur-Cèze, he spent most of his career in Orange and made several documented visits to papal Avignon. He apparently held no communal rabbinic office, supporting an unusually independent programme of Hebrew scholarship. מעשה חושב advanced arithmetic, combinatorics, and proof by induction. His philosophical masterpiece מלחמות ה׳, written from 1317 to 1329, examined immortality, prophecy, providence, divine knowledge, astronomy, creation, and miracles, sometimes departing sharply from ר׳ משה בן מימון. His astronomical observations and models criticised Ptolemy; his cross-staff and trigonometric work circulated beyond Jewish learned circles, and part of his astronomy was translated into Latin for Pope Clement VI. Between 1329 and 1338 he produced major biblical commentaries distinguished by close language, philosophical argument, scientific explanation, and practical moral lessons. Later authorities admired his learning while debating his positions on providence and divine foreknowledge. He died in 1344; the exact location is not securely established. No authentic likeness survives, and the former purported portrait has been removed.