Expression and the Perfection of Finite Individuals in Spinoza and Leibniz

It is obvious that both Spinoza and Leibniz attach importance to the notion of expression in their philosophical writings and that both do so in a similar fashion: They agree, for example, that the mind expresses the body (although this claim has rather different meanings for each of them). Another - albeit related - use of 'expression' that appears in both thinkers provides a deeper insight into some metaphysical similarity as well as difference: The idea that expression is closely connected with the perfection and action of individual things. While this relation is explicit in Leibniz, I will show that it is also in a less straightforward way found in Spinoza and, furthermore, that the relation of expression in regards to perfection is similar in Spinoza and Leibniz as both of them regard individuals as perfect insofar as they express the world and God. But one crucial difference in their accounts lies in the claim that, for Spinoza, what is being expressed and gives rise to perfection can be privative in nature, while such a thing cannot be the object of an expression for Leibniz. As I will argue, this not based merely on their different metaphysical views, but also on a difference in what can serve as content of an expression.