Constructing Reason

Abstract In The Architectonic of Reason , Lea Ypi provides an illuminating and innovative interpretation of the Architectonic in the first Critique . Ypi argues that Kant’s project of uniting practical and theoretical uses of reason in a critical metaphysics ultimately fails because practical reason does not have its own domain in which to legislate. This article challenges Ypi’s objection to practical reason’s lack of a domain in the first Critique . Its main contention is that reason’s need for unity in legislation may be satisfied by a belief in God as a necessary practical presupposition rather than a dogmatic metaphysical reality.