Leibniz’s dynamics and the role of architectonic principles in its development

One of Leibniz's main achievements in natural science has been his invention of the 'dynamics.' Thanks to contemporary scholarship, we are presently in a better position than previously for tracing out the sequence of steps that resulted in the canonical formulations of this new 'science of power and action' in the 1690s, somewhat in parallel with the advent of Leibniz’s late metaphysics. Starting with the 1671 twofold Theoria motus, this story displays the close connection Leibniz’s early mechanics bore with the model, inspired by Hobbes, of a physics to be alternatively built a priori and a posteriori. The revised mechanics of the 1678 De corporum concursu as well as the demonstration of the vis viva principle in the 1686 Brevis demonstratio essentially followed the a posteriori way, but the twofold structure of arguments came back on stage in the 1689-1690 Dynamica as well as in later presentations. My enquiry concerns the successive versions of this twofold structure and the way architectonic principles were progressively called upon to formalize the theory of 'power and action' through the various phases of its complex methodological evolution.