In this paper, I will discuss an on Spinoza written by Hans Jonas in 1965: “Spinoza and the Theory of Organism”. First, I will present Jonas’main argument and the theoretical assumptions of his essay; then I will expand on the possible development of these assumptions with the aim of proposing a complete theory of being; a Spinozian ontology. Finally, my argument will focus on the interpretation of Spinoza’s work and thought as an organicism and the possible relations between this reading and Jonas’article.