Chapter 7 - The Boundary of Pure Reason

Summary

The chapter takes up the question of how and why Kant marks the limits of metaphysics, particularly in light of the skeptical challenges to reason’s use raised by Hume and Bayle. Here Kant’s distinction between our cognitive faculties – the heterogeneity thesis – plays a crucial role, since it allows Kant to set the boundaries of metaphysics at the cognizable, which requires sensible content that dogmatic metaphysics is unable to provide. Kant’s account of limits and boundaries bears a suggestive similarity to the claims Wittgenstein makes in the Tractatus, and the essay lays out some of the fruitful ways in which the latter work can help shed light on Kant’s argument in the Prolegomena.