Francis Warrain (1867-1940), French artist, philosopher, and mathematician, was the author of a dozen works of exegesis and metaphysics. In particular, he evoked the thought of the visionary Polish mathematician Hoëné Wronski, as well as music, geometry, and various themes dear to esotericists. Warrain's vast body of work bears witness to a period in the history of science when enlightened amateurs-heirs to the scholars of ancient times-still produced respected scientific work, without any official functions or attachment to institutions, but with unflagging self-sacrifice and capacity for hard work. We know that his works on Wronski were in Jacques Lacan's library, and that Gilles Deleuze refers to Warrain's works on Wronski his Difference and Repetition. Modern esoteric currents continue to claim him as their author, as evidenced by various reprints of his works. His books on Kabbalah and Geomancy, written around 1910 (before he devoted himself entirely to the study of mathematical symbolism), the most popular facet of his intellectual approach, have been translated into several languages.