For Kant, the moral law is the causal law of freedom. However, it is not an explanatory causal law. It is instead a causal law of imputation: it is a law according to which we can be held responsible for the actions the law declares necessary; that is, it is a law according to which we can be considered the causes of whether or not we act lawfully. In this way, the moral law makes possible a kind of causality that (...) is a “third thing” between natural necessity and blind chance. This essay traces the origins of this view to the Antinomy of Pure Reason of the first Critique and shows how it is refined in Kant’s foundational texts in practical philosophy of the 1780s and in his reflections on the nature of human evil from the 1790s. (shrink)