Philosophy of Physics Seminar (Thursday - Week 8, HT25)

Abstract: Many philosophers of physics maintain that a physical theory that exhibits (certain kinds of) symmetries is flawed. This is because it is believed that a theory with symmetries posits or otherwise invokes “excess structure”. In an influential paper, Dewar (2019) introduces a distinction between “reduction” and “sophistication” as alternative but equivalent ways of removing excess structure. In this talk, I argue that this distinction fails to capture several cases of alternative formulations of theories in physics. More carefully, I argue that one cannot draw the distinction between sophistication and reduction in a way that maintains the core features of Dewar’s definitions of these terms and that vindicates the idea that 1. the standard formulations of theories such as General Relativity and Yang-Mills theory are sophisticated and that 2. there exists a theoretically equivalent reduced alternative. I use this argument tohighlight that there are two notions of “reduction” that  ought to be distinguished, both in motivation and in outcome.