The aim of this work is to analyze the points of contact and the influences that Descartes’ philosophy had in Nietzsche’s works. Following and elaborating the analysis by Giuliano Campioni on the subject, we will try to show how the appreciation of Descartes by Nietzsche represents a fundamental starting point for the comparison between the esprit français and the esprit allemand, which is a crucial junction in the philosophy of the German thinker. In his works of maturity, there is in fact, after the overcoming of the influences of Schopenhauer and Wagner, the profound metabolization of ideas such as those of “passion for knowledge” and “method”, central in the Discours de la méthode, in polemic with intuitional metaphysics typical of German romanticism. These concepts will represent for Nietzsche some useful tools to outline his notion of physiology in which the body represents the complex fil rouge against the transparency and simplicity of the classical subject.