Nietzsche versus Kant on the possibility of rational self-critique

I consider an epistemological, methodological dispute between Nietzsche and Kant about the possibility of rational self-critique: an activity where the intellect reflects on its cognitive powers, demarcates the proper use and limitations of these powers, and thereby achieves a systematically complete insight into what we can and cannot know. Kant affirms whereas Nietzsche denies that we can successfully conduct such a self-directed rational enquiry. By reconstructing the central argumentative moves that Nietzsche and Kant do or could make to defend their respective position, I trace their disagreement to starkly diverging models of philosophical enquiry, of what philosophy is and ought to be all about.