Siegel argues that the Kuhnian relativism presented in ?Kuhn's Epistemological Relativism? fails because it neglects the possibility of rational choice in science between rival paradigms? own incommensurable standards on the basis of ?paradigm?neutral external standards?. In reply, it is argued (1) that Siegel has given no reason to believe that there are such external standards in science, (2) that the mere ?possibility? of such standards in scientific debate is not sufficient to vitiate Kuhn's relativism, (3) that the actual existence of (...) rational debate concerning the internal standards of rival paradigms does not entail (as Siegel claims) the existence of ?paradigm?neutral external standards?, and finally (4) that Kuhn's relativism concerning standards in science does not lead (as Siegel claims) to a ?reductio? which undermines the philosophical standards implicit in Kuhn's argument. (shrink)