What kind of monism is Spinoza's?—A new analysis

The question of whether Spinoza's metaphysics qualifies as a version of priority monism is debated in the literature, though the significance of this debate is arguably understated. This article clarifies why it matters for Spinoza scholarship and offers a tentative answer. First, I demonstrate how priority monism is implicitly suggested in the Short Treatise (KV) as a solution to the tension between the unity of substance and the plurality of modes. Second, I propose a new interpretation of Spinoza's mature ontology in the Ethics that explains how and why he distanced himself from this earlier priority monism. Contrary to the prevailing narrative that Spinoza's mature metaphysics is simply not priority monism, I offer a textual defense of the possibility that Spinoza self‐consciously abandoned it by discovering a superior solution to the aforementioned metaphysical puzzle that had troubled him in the Short Treatise .