Abstract

Essences play a central role in Spinoza’s philosophy, not only in his metaphysics, but also in his philosophy of mind, his theory of affects, and his political philosophy. Despite their importance, however, it is surprisingly difficult to determine what exactly essences are for Spinoza. On a widespread reading, the essence of X is nothing but the concept of X. This paper argues against this identification of essences and concepts. Spinozistic concepts are maximally inclusive: the concept of X contains everything that is needed to make X conceivable. The essence of X, in contrast, is more limited in scope and does not include everything that is needed to make X conceivable. Thus, Spinoza avoids the ‘overloading’ of essences and the problems that would ensue. The account developed in this paper has a surprising implication, namely that the essences of non-divine, singular things do not suffice to render these things fully conceivable on Spinoza’s view. Thus, Spinoza breaks with a tradition according to which the essence of a thing states ‘what the thing is.’ As a result, his conception of essence is much further removed from traditional Aristotelian accounts, and from other seventeenth-century accounts, than usually acknowledged.