Confirmation, or pursuit-worthiness? Lessons from J. J. Sakurai's 1960 theory of the strong force for the debate on non-empirical physics.

Over the last few decades, our theories of fundamental physics have become increasingly detached from empirical data. Recently, Richard Dawid has argued that the progressive separation of theory from experiment is concomitant with a number of changes in the methodology of the discipline. More precisely, Dawid has argued that the new methods of fundamental physics amount to a form of non-empirical confirmation, and that physical theories may therefore be confirmed even in the absence of empirical data. In this paper, I critically engage with Dawid's views on non-empirical physics. My main target is the excessively central role that, in my view, the notion of non-empirical confirmation plays on Dawid's analysis. I will therefore argue that, while non-empirical methods may legitimately be employed in physics, those are not always deployed with the purpose of confirming scientific theories. Non-empirical arguments may also be used in order to ground pragmatic choices regarding what theories deserve to be further developed-and this is an aspect of the work that non-empirical methods perform that cannot be solely understood in terms of Dawid's notion of non-empirical confirmation. I support these claims by making use of a case-study from the early history of particle physics. The case-study concerns a theory of the strong force that J. J. Sakurai introduced in 1960. As we shall see, both the genesis of Sakurai's theory as well as the arguments that he used to defend it provide direct support for my own views on the role that non-empirical methods play in physics. Finally, I conclude the paper by introducing a notion that I believe is useful in making sense of the manner in which the pragmatic and the epistemic dimensions of non-empirical reasoning relate to each other, namely the notion of a cognitive attitude.