On Kant's Concept of Law

The article aims to clarify Kant's concept of law, which he developed in the "Metaphysische Anfangsgrunde der Rechtslehre" from 1797. Decisive for Kant's concept of law is the distinction between internal and external relations of persons. Law is restricted to external relations. So the crucial question is: Where does Kant draw the line between internal and external relations? Four possibilities are analysed in an order of increasing extent: (1) only causal consequences of our actions in the external world beyond our bodies; (2) causal consequences in the external world plus our externally empirical sensible bodily behaviour; (3) causal consequences in the external world plus all physiological changes in the actor like nerve stimulations and brain activities; (4) all features of (3) plus all non-a-priori mental and emotional changes like emotions, inclinations, empirical concepts, hypothetical imperatives etc., in sum: Kant's division between homo noumenon and homo phaenomenon. While modern interpretations would perhaps endorse possibility (2), Kant has chosen - so the main argument of the article - the widest possible alternative (4). This brings him to a very extensive concept of law. Only in reflecting this wide extent of Kant's concept of law, we are able to understand his philosophy of law.