Abstract

This chapter takes a fresh look at 3d2 of Spinoza’s Ethics, an absolutely pivotal definition for the ethical theory that ensues. According to it, “we act when something happens, in us or outside us, of which we are the adequate cause,” whereas we are passive “when something happens in us, or something follows from our nature, of which we are only a partial cause.” The definition of activity has puzzled scholars: how can we be an adequate, i.e. complete, cause of an effect outside us (which clearly involves other causal factors as well)? However, the definition of passivity is hardly unproblematic either: how can something follow from the patient’s nature so that the patient can nevertheless be considered only a partial cause? I begin by outlining 3d2 and situating it in the historical context formed by Descartes, Hobbes, and the Aristotelian tradition. Then I show that the existing interpretations do not solve the problem of activity and argue that unraveling the problem requires taking properly into account the distinction between immanent and transeunt causality. In relation to the definition of passivity, I argue that Spinoza’s geometry-inspired theory of essence constitution offers the key to understanding the nature of passions.