He was the French advocate of the
symbolic logic that emerged in the years before World War I, thanks to the writings of
Charles Sanders Peirce,
Giuseppe Peano and his school, and especially to
The Principles of Mathematics by Couturat's friend and correspondent
Bertrand Russell. Like Russell, Couturat saw symbolic logic as a tool to advance both mathematics and the
philosophy of mathematics. In this, he was opposed by
Henri Poincaré, who took considerable exception to Couturat's efforts to interest the French in symbolic logic. With the benefit of hindsight, we can see that Couturat was in broad agreement with the
logicism of Russell, while Poincaré anticipated
Brouwer's
intuitionism. His first major publication was
De Platonicis mythis (1896). In 1901, he published
La Logique de Leibniz, a detailed study of
Leibniz the logician, based on his examination of the huge Leibniz
Nachlass in Hanover. Even though Leibniz had died in 1716, his
Nachlass was cataloged only in 1895. Only then was it possible to determine the extent of Leibniz's unpublished work on logic. In 1903, Couturat published much of that work in another large volume, his
Opuscules et Fragments Inedits de Leibniz, containing many of the documents he had examined while writing
La Logique. Couturat was thus the first to appreciate that Leibniz was the greatest logician during the more than 2000 years that separate
Aristotle from
George Boole and
Augustus De Morgan. A significant part of the 20th century Leibniz revival is grounded in Couturat's editorial and exegetical efforts. This work on Leibniz attracted Russell, also the author of a 1900 book on Leibniz, and thus began their professional correspondence and friendship. In 1905, Couturat published a work on logic and the
foundations of mathematics (with an appendix on Kant's philosophy of mathematics) that was originally conceived as a translation of Russell's
Principles of Mathematics. In the same year, he published ''L'Algèbre de la logique'', a classic introduction to
Boolean algebra and the works of
C.S. Peirce and
Ernst Schröder. In 1907, Couturat helped found the
constructed language Ido, an offshoot of
Esperanto, and was Ido's principal advocate over the remainder of his life. By advocating a constructed international language, constructed along logical principles and with a vocabulary taken from existing European languages, Couturat was paralleling
Peano's advocacy of
Interlingua. By pushing Ido, Couturat walked in Leibniz's footsteps: Leibniz called for the creation a universal symbolic and conceptual language he named the
characteristica universalis. Couturat, a confirmed
pacifist, was killed when his car was hit by a car carrying orders for the mobilization of the
French Army, in the first stage of
World War I. He appears as a character in
Joseph Skibell's 2010 novel,
A Curable Romantic. ==Works==