On the Meaning of the Correspondence Principle and the Unity of Physics

Abstract

The article deals with the problem of the unity of physics, which arises because of the theoretical pluralism in physics. I argue that the incommensurability of physical theories does not prevent us from claiming the unity of physics. The reason for that is a set of so-called bridge principles connecting different theories in the domain of physics. I support my argument by considering the correspondence principle. The principle should be regarded not as a substantial principle, but as a generalization principle similar to Kant’s principle of the unity of apperception. I conclude that the correspondence principle is not only a semantic principle, which governs the use of the same concepts in physical theories but also an ontological principle concerning the same referents of the physical concepts.