 In just the way that some authors suggest that the miracle argument is an instance of fallacious reasoning—the base rate fallacy (see  section 2.1)—some  suggest that the pessimistic induction is likewise flawed (Lewis 2001; Lange 2002; Magnus &amp; Callender 2004). The argument is analogous: the putative failure of reference on the part of past successful theories, or their putative lack of approximate truth, cannot be used to derive a conclusion regarding the chances that our current best theories do not refer to unobservables, or that they are not approximately true, unless one knows the base rate of non-referring or non-approximately true theories in the relevant pools. And since one cannot know this independently, the pessimistic induction is fallacious. Again, analogously, one might argue that to formalize the argument in terms of probabilities, as is required in order to invoke the base rate fallacy, is to miss the more fundamental point underlying the pessimistic induction (Saatsi 2005b). One might read the argument simply as cutting a supposed link between the empirical success of scientific theories and successful reference or approximate truth, as opposed to relying on an inductive inference per se. If even a few examples from the history of science demonstrate that theories can be empirically successful and yet fail to refer to the central unobservables they invoke, or fail to be what realists would regard as approximately true, this constitutes a prima facie challenge to the notion that only realism can explain the success of science.