In this remarkable work, Gilles Deleuze, the renowned French philosopher, reflects on one of the thinkers of the past who most influenced his own sweeping reconfiguration of the tasks of philosophy. For Deleuze, Spinoza, along with Nietzsche and Lucretius, conceived of philosophy as an enterprise of liberation and radical demystification. He locates in Spinoza "a set of affects, a kinetic determination, an impulse" and makes Spinoza into "an encounter, a passion."

Expressionism in Philosophy was the culmination of a series of monographic studies by Deleuze (on Hume, Bergson, Nietzsche, Proust, Kant, and Sacher-Masoch) and prepared the transition from these abstract treatments of historical schemes of experience to the nomadology of Capitalism and Schizophrenia (Anti-Oedipus and A Thousand Plateaus, co-authored with Félix Guattari). Thus, Expressionism in Philosophy is both a pivotal reading of Spinoza's work and a crucial text within the development of Deleuze's thought.