  However, a recurrent motif in twentieth century philosophy of science is that the bearing of evidence on theory is mediated by factors that might vary between individuals in ways that do not admit of such rational adjudication. Imagine two eminent scientists, both of whom are thoroughly acquainted with all of the available evidence which bears on some theory. One believes the theory, the other believes some different, incompatible theory instead.  Must one of the two scientists be making a mistake about what their shared evidence supports? Perhaps the most natural answer to this question, at least at first blush, is ‘Yes’. A fair amount of twentieth century philosophy of science shied away from this natural answer, however, at least in part because of a growing awareness of just how often eminent, fully-informed and seemingly rational scientists have disagreed in the history of  science.[30]  Thus, Thomas Kuhn (1962) would maintain that both scientists might be perfectly rational in holding incompatible theories, inasmuch as rationality is relative to a paradigm, and the two scientists might be operating within different paradigms. Similarly, Carnap (1952) would maintain that both scientists might be rational because rationality is relative to an inductive method or confirmation function, and the two scientists might be employing different inductive methods or confirmation functions. As we have noted, for the contemporary Bayesian, how it is reasonable to respond to a given body of evidence depends upon one's prior probability distribution: the two scientists might thus both be rational in virtue of possessing different prior probability distributions. There are, of course, important differences among these accounts of rationality. But notice that they each possess the same structure: what it is reasonable for one to believe depends not only on one's total evidence but also on some further feature F (one's prior probability distribution, paradigm, inductive method.).  Because this further feature F can vary between different individuals, even quite different responses to a given body of evidence might be equally reasonable. On such views, the bearing of a given body of evidence on a given theory becomes a highly relativized matter. For this reason, the capacity of evidence to generate agreement among even impeccably rational individuals is in principle subject to significant limitations. 