7. Hans Kelsen and Practical Reason

The critique of practical reason, in all its possible forms, has a far more important and decisive role in Kelsen’s thought than the rejection of Natural law doctrine. Admitting that a practical use of reason is legitimate, namely, that there is a possible connection between intellect and will, would mean destroying the whole foundation of the scientific undertaking of the Pure Theory of law and its conception of the legal norm, which is its central aspect. By depriving practical reason of all foundation, any reference to agency and practical deliberation is excluded from Kelsen’s theory of law. Consequently, the Ought loses all capacity of attraction and motivation of human action, rendering Kelsen’s normativity inert. This chapter intends to show that Kelsen’s enterprise of purifying legal science only attains its fulfilment when the practical dimension of reason itself is eradicated, along with the sociological or political or ideological aspects of law; and in this way the Pure Theory of law is forced to forgo some of its distinctive features, as is evident in Kelsen’s final works; and that the demise of practical reason strongly destabilizes the Pure Theory of law itself.