LEON BRUNSCHVICG (1869-1944) French philosopher who considerably influenced modern European thought with his brand of "critical idealism", using mathematical judgment to extend the teachings of Kant, Hegel, Plato, Descartes, Spinoza and Pascal. Especially rare A.L.S. 2pp. 4to., [n.p.], July 8, 1921 in French, not translated. Usual folds, scrape to recto obscures several words of text, otherwise very good condition. $250-300