This volume features a critical edition of the recently rediscovered manuscripts written by the French philosopher Louis Couturat (1868-1914). It includes the transcriptions of three of his believed to be lost manuscripts: first the “Cours de Caen: 1898-99” on various systems of symbolic logic, second his lecture at the Collège de France “Histoire de la logique formelle moderne", and third his textbook on mathematical logic. The manuscripts document the early reception of mathematical logic in France and provide insights into the first introduction of the French reader to the work of Gottlob Frege and Bertrand Russell. It is the aim of the editors of this volume to contribute to the history of symbolic logic, particularly the history of its dissemination and its teaching in France. At the same time, the volume contributes to an alternative history and conception of philosophy in which semiotics and concrete mathematical practice stand in focus. The book is interesting for students and researchers in the history of philosophy, mathematics, and logic.