The aim of this paper is to show the unity and consistency of Kant’s reflections throughout all three sections of the Canon of Pure Reason. More specifically, I argue that Section 3, which is devoted to the issue of Fürwahrhalten, or taking-to-be-true, is crucial to achieving the methodological goal of the Canon, which is to justify the legitimacy of the speculative assumptions of pure reason. After examining the historical roots of Kant’s notion of a transcendental doctrine of method, I focus (...) on the methodological role that the practical element plays in the first two sections of the Canon. I then show how the limitations of Kant’s argument necessitate the introduction of a third crucial section, which serves both an analytic and an orientative function. (shrink)