The Significance of Non-Empirical Confirmation in Fundamental Physics

In the absence of empirical confirmation, scientists may judge a theory’s chances of being viable based on a wide range of arguments. The paper argues that such arguments can differ substantially with regard to their structural similarly to empirical confirmation. Arguments that resemble empirical confirmation in a number of crucial respects provide a better basis for reliable judgement and can, in a Bayesian sense, amount to significant $\mathit{\text{non-empirical}}$ confirmation. It is shown that three kinds of non-empirical confirmation that have been specified in earlier work do satisfy those conditions.