Real Enough: The Metaphysics of Epistemic Structural Realism

Abstract Epistemic Structural Realism (ESR), the view that structure is all we can know about the unobservable world, has been criticized for lacking sufficient metaphysical depth to qualify as a genuine form of realism. This paper defends a refined version of ESR – which I call agnostic ESR – that avoids these objections by committing to knowledge of detectable, concrete structures while maintaining agnosticism about the existence of objects with intrinsic properties. I respond to prominent criticisms, including Newman’s objection, concerns about ESR’s metaphysical clarity, and potential collapse into other views, by showing that agnostic ESR can provide a rigorous account of structural knowledge grounded in empirical science that cannot be defended by advocates of other realist positions. I argue that agnostic ESR is metaphysically robust to deserve the realist label.