Volume 22, December 2012
Spinoza on the “Principles of Natural Things”
This essay considers Spinoza’s responses to two questions: what is responsible for the variety in the physical world and by what mechanism do finite bodies causally interact? I begin by elucidating Spinoza’s solution to the problem of variety by considering his comments on Cartesian physics in an epistolary exchange with Tschirnhaus late in Spinoza’s life. I go on to reconstruct Spinoza’s unique account of causation among finite bodies by considering Leibniz’s attack on the Spinozist explanation of variety. It turns out that Spinoza’s explanations of the variety of bodies, on the one hand, and of causation among finite bodies, on the other, generate a tension in his system that can only be resolved by taking Spinoza to employ two notions of “existence.” I conclude by offering evidence that this is in fact what Spinoza does.