Abstract

In this paper, I show that Maupertuis and Euler offer a contrasting conception of metaphysics of nature. It consists mainly for them in repositioning cosmology in relation to natural sciences. Instead of considering metaphysics to be at the foundation of scientific theories, as was assumed by Descartes, Wolff, and, in a certain way, Kant, or simply prohibiting the very idea of a cosmology, as d’Alembert would stipulate at the same period, Maupertuis and Euler invert the order of disciplines to give priority to physical sciences over metaphysics. This repositioning leads of course to several questions : first, how does scientific theories validate or deny metaphysical principles? Even more important, which role falls to metaphysics of nature given that sciences not only possess a theoretical autonomy, but also a priority over ontological reflections? Besides, it seems that metaphysics would be reduced, for these two philosophers, to the realm of cosmology alone, in particular to questions concerning force and the principle of least action, the ontological status of space and time, and the first constituents of matter, such as extension, inertia, impenetrability, and motion.