Few thinkers have experienced more contradictory interpretations than Baruch de Spinoza. At times he was regarded as an atheist and rationalist, at other times as a pantheist and vitalist, and sometimes as a Jewish critic of religion and heir to Marranism. However, in the 20th and 21st centuries, Spinoza is favored as a materialist who teaches Marxism a lesson in non-dogmatic thinking and non-teleological dialectics. Starting from Althusser's interest in the concept of immanent causality, Katja Diefenbach reconstructs the post-Marxist Spinoza readings from Negri to Balibar. The unconventionality of Spinoza's philosophy is presented, discussing the self-formation of matter, the affective production of thought, the self-governance of the multitude, and the heterogenesis of being. How could these anachronistic doctrines of the 17th century serve to address the problematic concepts of Marxism and its entirety?.