Theory Change,Structural Realism,and the Relativised A Priori

In this paper I claim that Quinean naturalist accounts of science, that deny that there are any a priori statements in scientific frameworks, cannot account for the foundational role of certain classes of statements in scientific practice. In this I follow Michael Friedman who claims that certain a priori statements must be presupposed in order to formulate empirical hypotheses. I also show that Friedman’s account, in spite of his claims to the contrary, is compatible with a type of non‐Quinean naturalism that I sketch. Finally I also show that Friedman’s account needs amending because it cannot provide a rational account of theory change. I accomplish this by arguing for a structural realist view of theory change. I show how this view fits well with an account like Friedman’s and helps it deal with the problem of theory change and in retaining its superiority over Quinean naturalism.