  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
\textit{non-empirical} confirmation. It is shown that three kinds of
non-empirical confirmation that have been specified in earlier work do satisfy
those conditions.
