Richard Falckenberg (1851–1920) was among the first historians of philosophy to support the argument that Nicholas of Cusa was a modern philosopher. It is found in his book Grundzuge der Philosophie des Nicolaus Cusanus mit besonderer Berucksichtigung der Lehre vom Erkennen (1880). Already in this work, in fact, Falckenberg puts forward a number of suggestions that little by little will become part of the Cusanian historiography. Among them, above all is the idea that the modernity of Cusanus is derived from his innovative theory of knowledge. Falckenberg’s celebrity would later be reduced and obscured by the most famous historians of philosophy, to whom has been attributed the origin of the modern interpretation of Cusa, Ernst Cassirer and his school. In this article, I want to come back to Falckenberg’s book and recover in a schematic way his main arguments about the proximity of Cusanus to the philosophies of Leibniz, Fichte, and the positivists.