Relationalism about Space and Time: Revisiting an Unfinished Revolution

This essay revisits the Leibnizian/Machian tradition of relationalism in light of recent developments in physics and metaphysics. While historically dismissed as conceptually elegant but technically deficient, relationalism has re-emerged as a viable foundation for fundamental physics through the advent of pure shape dynamics and the metaphysics of self-subsisting structures. These approaches address longstanding philosophical and physical challenges concerning empirical adequacy, the reconstruction of physical magnitudes, and the grounding of dynamical laws. By re-examining the trajectory of relationalist thought and clarifying how recent proposals fulfill its core ambitions, the essay presents a case for the renewed relevance of relationalism in foundational research.