 Interestingly, the Bayesian predictivist has an escape (neatly anticipated, and criticized, by Glymour 1980a, 91–92). Consider Einstein and Mercury once again. As effectively pointed out by Norton (2011a, 7), Einstein was extremely careful to emphasize that the precession phenomenon had been derived “without having to posit any special [auxiliary] hypotheses at all”. Why? Well, presumably because if one had allowed herself to arbitrarily devise ad hoc auxiliaries (within \(k\), in our notation) then one could have been pretty much certain in advance to find a way to get Mercury’s data right (remember: that’s the lesson of the underdetermination theorem). But getting those data right with auxiliaries \(k\) that were not thus adjusted—that would have been a natural consequence had the theory of general relativity been true and it would have been surprising otherwise. Arguably, this line of argument exploits much of the use-novelty idea within a predictivist framework. The crucial points are (i) that the evidence implied is not a verified empirical statement \(e\) but the logical fact that \(h \wedge k\) entails \(e\), and (ii) that the existence of this connection of entailment was not to be obviously anticipated at all, precisely because \(h \wedge k\) and \(e\) are such that the latter did not serve as a constraint to specify the former. On these conditions, it seems that \(h\) can be confirmed by this kind of “second-order” (logical) evidence in line with (SP) while TE is concurrently preserved.