Galois, Évariste

(1811-1832)

   mathematician

   Born in Bourg-le-Reine, Évariste Galois, who was twice rejected by the École polytechnique, entered the École normale superieure in 1830, from which he was expelled a year later for publishing an article that violently denounced the "reactionary nature of the director." An active republican, who was twice incarcerated, he continued his work in mathematics while in prison. The essence of the work of this genial mathematician is found in his memoir Sur les conditions de résolubilité des equations par radicaux (1831), in which he puts forth the theory of substitution sets. The night before the duel in which he was killed, he edited two memoirs on the subjects about which he was most passionate: a manifesto, À tous les républicains, and a mathematical testament in which he further explains his theory on algebraic equations, building on the work of the Norwegian mathematician Niels Hen-rik Abel. The central idea in the works of Galois is the notion of sets that later became fundamental to the study of mathematics.