The Trouble with Feelings, or Spinoza on the Identity of Power and Essence

Spinoza claims both that a thing’s essence is identical to power, and that emotions are fundamentally variations in this power. The conjunction of these two theses creates difficulties for his metaphysics and ethics alike. The three main worries concern the coherence of Spinoza’s accounts of essence, diachronic identity, and emotional “bondage,” and put in question his ability to derive ethical and psychological doctrines from his metaphysical claims. In response to these difficulties, this paper offers a new interpretation of Spinoza’s account of affects and his doctrine of the identity of power and essence. It shows that what is fundamental to his ontology of affects is the relation of modification or determination, a relation central to his ontology more generally. The paper argues that we cannot simply identify power and essence but should instead take affects to modify or determine essences as particular exercises of power (particular desires, appetites, and volitions). That is, Spinozistic essences should be viewed as intrinsically determinable, with affects supplying the determinations, and as consisting not in rigid sets of determinate properties, but in ranges of variable properties.