Abstract

Kant's Reason develops a novel interpretation of Kant’s conception of reason and its philosophical significance, focusing on two claims. First, it argues that Kant presents a powerful model for understanding the unity of theoretical and practical reason as two manifestations of a unified capacity for theoretical and practical understanding (or “comprehension”). This model allows us to do justice to the deep commonalities between theoretical and practical rationality, without reducing either to the other. In particular, through it, we see why the activities of both theoretical and practical reason are governed by a version of the Principle of Sufficient Reason, while also seeing why reason is essentially autonomous. At the same time, Kant's Reason also reads Kant as presenting us with a compelling picture of the role that reason (as a capacity or power) should play in a systematic approach to foundational philosophical questions. In doing so, it argues for an account of the fundamental norms that apply to rational beings that treats as fundamental neither substantive reasons or values nor merely structural rationality, but instead a robust conception of reason as a power or capacity — namely, the capacity for theoretical and practical understanding. The result is a form of “rational constitutivism” – one which contrasts both with the forms of “reasons fundamentalism” that are currently fashionable and the forms of “agency-first constitutivism” that have dominated much of Kantian metaethics. In this sense, the aim of the book is to vindicate Kant’s insistence that his philosophy represents nothing more or less than reason’s implicit self-understanding coming to explicit and systematic self-consciousness.