This chapter explores the parallels between the critique of pure reason and the establishment of a civil condition in natural right theory. It shows how Kant’s conception of laws is ingrained in an extensive legal framework by focusing on two images, the one portraying the critique as the tribunal of reason and the other depicting the critique as the establishment of a rightful condition which is analogous to the establishment of a civil state. These images show that Kant’s account of a priori laws is not merely a colourful way of expressing a new philosophical approach; he is building an entire framework around a legal structure. In addition, the state of nature metaphor shows how the critique aims to provide a procedure for ending conflicts in metaphysics and thereby establish perpetual peace in philosophy.

This chapter places Kant’s conception of a priori laws within the framework of the legal metaphors. It introduces the relevant aspects of natural right theory and the notion of laws in the natural sciences as historical background to the legal metaphors. The main argument is that Kant’s notion of laws is embedded in his legal metaphors and his account of natural regularities as lawful also originates in the natural right framework. This serves as background to Kant’s account of the understanding as prescribing laws to nature and to thought. The background of Kant’s notion of laws in natural right and natural science shows how reason’s a priori laws are both descriptive of regularities in nature and prescriptive of valid judgements.