ABSTRACT
This chapter analyses certain ambivalence in Leibniz's conception of action. It argues that the degree of reality and perfection of perception enables us to grasp the individuality of substances. It then examines how Leibniz integrates these medieval reflections into his own thinking and how he makes this traditional conceptual apparatus a means to mathematize the real and, which is crucial for the present purposes, to shed light on the process of individuation of substance. In the 'Dynamica de potentia', Leibniz develops a distinction between violent action and formal action. Leibniz appealed to dynamic action in order to establish his metaphysical conception of action. The hypothesis of pre-established harmony contests the claim that there is influence of a substance on another substance. The analysis the author have developed bestows meaning on formulas that people frequently find in Leibniz's texts, which suggest that metaphysics is a means of illuminating dynamics.
