This article criticizes the attempts by Bas van Fraassen and Michael Friedman to address the challenge to rationality posed by the Kuhnian analysis of scientific revolutions. In the paper, I argue that van Fraassen's solution, which invokes a Sartrean theory of emotions to account for radical change, does not amount to justifying rationally the advancement of science but, rather, despite his protestations to the contrary, is an explanation of how change is effected. Friedman's approach, which appeals to philosophical developments at a meta-theoretical level, does not really address the problem of rationality as posed by Kuhn's work. Instead of showing how, despite revolutions, scientific development is, indeed, rational, he gives a transcendental account of rational scientific progress.