Abstract
In Part 3, I will discuss the problems of inertia and gravity in Leibniz, and present three conjectures: If Leibniz were really ready to insist on relativity, he would have to assert the relativity of inertial motion. In Leibniz’s theories of dynamics and geometry, there was a struggle between his predilection for straight line and his adherence to an optimality principle. Gravity, as well as inertia, can be considered as a universal feature of the world, so that the foundation of both may have a common root. Further, drawing on the results in Part 1 and Part 2, I will argue for the need of a unified interpretation of Leibniz’s metaphysics and dynamics. My three conjectures as regards Leibniz’s possible treatment of inertia and gravity are proposed along a unified interpretation, in terms of my informational reconstruction of Leibniz’s philosophy. Finally, the most important features of the informational interpretation are summarized. The synopsis of the whole paper is added.