In his doctoral dissertation, completed in 1922 under the direction of Edmund Husserl and published in 1925 in the Jahrbuch für Philosophie und Phänomenologische Forschungen, Dietrich Mahnke proposed a very valuable overview of the so-called "Leibniz Renaissance". As indicated by the choice of his title: Leibnizens Synthese von Universalmathematik und Individualmetaphysik, this renaissance was seen by Mahnke as marked by a tension between two Leibnizian programs: that of a "universal mathematics" and that of a "metaphysics of individuation". His agenda was to propose a way of reconciling these two programs through a point of view inspired by the development of Husserlian phenomenology. In this paper, I will concentrate on the first program, "universal mathematics" or mathesis universalis, and see how the interpretation of this Leibnizian theme was indeed a key point in the demarcation between different ways of articulating logic, mathematics and philosophy at the beginning of the XXth century.