Many philosophers have thought that Kuhn’s claim that there have been paradigm shifts introduced a problem for the rationality of science, because it appears that in such a change nothing can count as a neutral arbiter; even what you observe depends on which theory you already subscribe to. The history of science challenges its rationality in a different way in the pessimistic induction, where failures of our predecessors to come up with true theories about unobservable entities is taken by many to threaten the rationality of confidence in our own theories. The first problem arises from a perception of too much discontinuity, the second from an unfortunate kind of continuity, in the track record of science. I argue that both problems are on...