Radical ontic structural realism as a structuralist existence monism

Abstract Radical ontic structural realism (ROSR) argues that structure is all that there is and that objects are metaphysically eliminable. By making such claims, ROSR is widely considered metaphysically obscure. To address this, I propose a novel characterisation of ROSR, drawing on two metaphysical concepts: existence monism, attributed to Spinoza by Bennett (1984) and Spinoza’s concept of modes. These concepts are adaptable to ROSR, which becomes a structuralist existence monism, where putative objects are reconceptualised as modes of the world’s structure. This proposal directly contributes to solving two problems ROSR faces: (A) the need for a metaphysical framework clarifying ROSR’s key claims and (B) ROSR’s need to account for the apparent plurality of objects we experience. Drawing on Wallace and Timpson’s ( The British Journal for the Philosophy of Science, 61 :697-727) spacetime state realism, I suggest a solution to a third problem, (problem C) McKenzie’s ( Philosophy of Physics, 2 :1-23) challenge to ROSR’s status as a substantive metaphysical doctrine. My reformulation of ROSR is a natural interpretation of this solution. I also compare my proposal to French’s (2014) ROSR, and Esfeld and Lam’s (2011) moderate structural realism, highlighting my proposal’s advantages.