Published online by Cambridge University Press: 31 January 2017
Kant’s notoriously unclear attempt to defend the regulative principle of systematic unity as the supreme principle of theoretical reason in the Appendix to the Transcendental Dialectic has left its status a source of controversy. According to the dominant interpretation, the principle ought to be understood as a methodologically necessary device for extending our understanding of nature. I argue that this reading is flawed. While it may correctly affirm that the principle is normative in character, it wrongly implies that it binds with mere hypothetical necessity. I offer novel grounds for thinking that if reason’s principle is normative, then it binds agents categorically instead.