Published online by Cambridge University Press: 13 February 2014
Our rational inquiries necessarily take place within conceptual and epistemic frameworks, including our rational inquiries into the frameworks themselves. This fact, together with the existence of incommensurable frameworks, is exploited by a Kuhnian argument for conceptual and epistemic relativism which can be used to threaten the epistemic authority of science. It will be argued, however, that this move can be blocked by means of dialectical arguments that provide non-circular rational support for scientific frameworks, both conceptual and epistemic. These arguments proceed by means of conceptual and methodological analyses that reveal the presuppositions that are shared by those who subscribe to incommensurable frameworks. The frameworks that are better able to capture these presuppositions are objectively better than their competitors, and it will be argued that the conceptual and epistemic frameworks of science have precisely this advantage.