Abstract

In this paper I propose clearly to distinguish four fundamental types of intertheoretical relations that may be used to represent different types of theoretical change in empirical science. These four types can be represented formally through a refined version of the set-theoretical apparatus of structuralism. They may be described as: crystallization, theory-evolution, embedding, and replacement with partial incommensurability. They will be first explicated in intuitive, informal terms, and some historical examples will be suggested for each type. In the second part of the paper, the four types are characterized in structuralistic terms; the notions of a partial substructure and of a diachronic theory-net will play a central role