Ontic Structuralism and Fundamentality

Ontic structural realism (OSR) is the view that (i) in spite of the discontinuities that characterise the historical development of science, we can be realist about something, i.e., the concrete counterpart of certain theoretical structures that remain preserved across theory-change; and (ii) such structure is all there is in the actual world, at least at the fundamental level. It is thus a thesis about the fundamental—one whereby relations, not objects, are the basic building blocks of reality. However, there are in fact several dimensions to the structuralism-fundamentality link, and many alternative ways of cashing out the idea that reality is fundamentally structural. Arguably, these require a more systematic and detailed assessment than acknowledged in the literature so far. The chapter provides such an assessment based on considerations coming from both physics and analytic metaphysics, and concludes by pointing to a hitherto quite neglected theoretical option.