  If this thesis of the independence of 19th-century algebra of logic from Leibniz is accepted, it is possible to connect the discovery of Leibniz, the logician, with the Leibniz renaissance in early 20th century. In addition to Couturat’s book La logique de Leibniz d’après des documents inédits (1901), with a presentation of Leibniz’s logic in the spirit of the new logic, the following landmark publications have to be mentioned: Bertrand Russell’s A Critical Exposition of the Philosophy of Leibniz (1900), providing an axiomatic deductive reconstruction of Leibnizian metaphysics, and Ernst Cassirer’s Leibniz’ System in seinen wissenschaftlichen Grundlagen (1902), focussing on a Neo-Kantian interpretation of Leibniz’s philosophy. Undoubtedly, Couturat’s edition of Leibniz’s Opuscules et fragments inédits de Leibniz (Leibniz 1903), taken from the manuscripts in the Royal Library in Hanover and published in 1903, gave for the first time access to the wealth of Leibniz’s different approaches to logic.