Kant's Moral World

Abstract This book provides a systematic interpretation of Immanuel Kant’s practical metaphysics, building up to his controversial claim that there are rational grounds to affirm the existence of the immortal soul and God because they represent metaphysical conditions for the realization of a moral world. This interpretation takes a widespread approach to the faculty of reason in general, beginning with Kant’s investigation of the conditions for pure reason’s real use in the Critique of Pure Reason, which decide whether cognizing metaphysical objects like freedom, the soul, and God is possible for us. It then applies this general framework to the use of pure practical reason presented in the Groundwork and Critique of Practical Reason, arguing that practical cognition of the moral law and transcendental freedom qualifies as the paradigmatic instance of pure reason’s real use. This cognition establishes that practical reason has primacy over theoretical reason, and lays an objective foundation for Kant’s subsequent arguments for the existence of the soul and God. The book concludes by examining these claims in detail, arguing that they articulate both metaphysical and practical conditions for the realization of the moral world represented through the concept of the highest good.