This investigatory bibliographic project on Spinoza and the problem of universals draws four principal conclusions. (1) Spinoza is a realist concerning universals. Indeed, Spinoza endorses a radical form of realism known as universalism, the doctrine according to which every ontologically authentic entity is a universal. (2) Spinoza is a realist concerning universal species natures. He holds that a given species nature (such as human nature) is wholly instantiated in each species member. (3) Spinoza combines Aristotelian and Platonic realism. On the one hand, he holds that no universal is ontologically anterior to the one substance God. On the other hand, he holds that all universals with instantiations in the realm of modes are eternal forms ontologically anterior to those instantiations. (4) Spinoza's pejorative remarks against universals are compatible with his realism. Such remarks are aimed merely at universals apprehendable by sense perception rather than pure intellect.
