From his day to ours, commentators have been struck by the Stoic currents flowing through Spinoza's thought. Leibniz branded him a leader of a “sect of new Stoics” which held that “things act because of [the universe's] power and not due to a rational choice” (Leibniz 1989, 282). A few years later Bayle said in his Dictionary, “The doctrine of the world-soul, which was . . . the principal part of the system of the Stoics, is at bottom the same as Spinoza's.” In our times, scholars such as Amélie Oksenberg Rorty and Susan James - hailing Spinoza as “the best of Stoics” - have written articles with titles such as “Spinoza the Stoic” in which they argue that he matched or even surpassed the Stoicism of the ancient Stoics in all respects: metaphysically/physically, methodologically/logically, and normatively/ethically. The similarities between Stoicism and Spinozism are impressive, and they naturally lead to the thought that much would be learned about the two systems as well as larger philosophical issues if it could be determined how deep they run. In this essay, I contribute to that project, but with two important limitations. First, my exploration is purely philosophical; I will say nothing about Spinoza's knowledge of Stoicism. It is not that I don't have views on the issue or that I find it uninteresting; rather, it simply isn't possible for me to undertake both conceptual analysis and Rezeptionsgeschichte in the space available.