Diego Arana Segura

This paper presents a novel framework for understanding theoretical equivalence that reconciles two familiar approaches to the problem: formal and content-based. Formal approaches are based on the logical and syntactical features of theories, while content-based approaches focus on their content as construed in various metaphysical approaches to semantics. I argue that these approaches are complementary and that a deeper view of equivalence emerges when we consider a theory's expansion potential—its capacity to be embedded in broader theoretical contexts. This notion links content to syntax, as syntactical structure constrains how a theory's expressions can be used, and this use in turn determines the theory's possibilities for representing the world across different theoretical contexts. The framework is applied to various cases where formal and content-based approaches face difficulties, showing that it can explain the equivalence and inequivalence of theories where previous approaches failed, and that it can better justify the strategies employed by proponents of these approaches in each case.