Abstract

Kant's theory of the regulative use of ideas of reason has been clarified considerably in recent scholarship. Little attention has been paid, however, to the question of whether the three classes of transcendental ideas—psychological, cosmological, and theological—may differ with regard to their regulative use. This article argues that there is a fundamental difference between the classes of ideas in this respect and that an examination of this heterogeneity can provide much‐needed insight into Kant's account of the utility of the cosmological ideas. First, I set out Kant's distinction between the cosmological ideas and their psychological and theological counterparts. Second, I clarify the two distinct regulative uses of each cosmological idea. I argue that the two opposed sides of the cosmological antinomies provide two different heuristic functions, aligned with the theoretical and practical interests of reason.