From the opening chapter of this book, I have argued that Spinoza’s theory of individuality is based on a particular brand of essentialism in which geometrical objects are taken as the paradigm for all things. When combined with certain dynamistic intuitions, the result is a view according to which essences make things what they are by determining how God’s power is modified so that certain individuals exist. Spinozistic essences thus occupy the esteemed ontological territory traditionally possessed by the substantial forms which had fallen into ill repute. The conatus doctrine, in turn, is such an important facet of Spinoza’s essentialism that only now, after having a proper grasp of that doctrine, are we in a position to draw a fairly comprehensive picture of the way in which its author thinks about the existence and individuation of finite entities. Perhaps most strikingly, Spinoza wants to elaborate a veritable ‘geometry of emotions’ that would tell us how certain properties or states are necessarily brought about when a creature with our kind of striving essence is modified by external causes that increase or decrease our power of acting. In what follows, my aim is to explicate the way in which this union of the geometrical paradigm and dynamism allows Spinoza to offer an elaborate account of human existence which takes place under two attributes, thought and extension.

Power and individuation

What makes things what they are? This is a basic metaphysical question; perhaps even the metaphysical question concerning finite existents. Stated more precisely the question is, what makes reality such that a specific individual exists? Moreover, what explains the individual persistence we encounter in the world? That is, why do things so often maintain their identity and being over time? Aristotelian scholastics were very much occupied with these questions, and they posed some thorny problems to Descartes and Hobbes. I believe that Spinoza patiently crafts an elegant theory of metaphysical individuation. At this point of this study, explicating its main idea can be done rather briefly.