Harvey Siegel's (1985) attempts to revive the traditional epistemological formulation of the rationality of science. Contending that “a general commitment to evidence” is constitutive of method and rationality in science, Siegel advances its compatibility with specific, historically attuned formulations of principles of evidential support as a virtue of his aprioristic candidate for science's rationality. In point of fact, this account is compatible with virtually any formulation of evidential support, which runs afoul of Siegel's claim that scientific beliefs must be evaluated with respect to their rationality. The unwelcome consequence of Siegel's view is that most any belief, scientific or pseudoscientific, can be defended as rational. Indeed, if we want to furnish a warrant for rational choice, we must turn to the very historically informed principles of evidential support that are dismissed by Siegel as providing a misleading portrait of science's rationality.