14. Kelsen on Natural Law and Legal Science

Kelsen rejects the scientific character of natural-law doctrine. For Kelsen, value judgments are ultimately not rationally justified but a matter of emotions. They can be rationally justified only relative to a certain moral or legal order. Kelsen also rejects the assumption of natural-law doctrines that value is immanent in reality. On the other hand, he suggests that legal science is possible regarding positive law, which is converted into a normative order by presupposing a “basic norm”. I will not challenge Kelsen’s critique of traditional natural-law doctrine, but discuss two issues: Can Kelsen’s own account of the “Pure Theory of Law” claim to be scientific, and does Kelsen’s critique of traditional natural-law theories affect modern versions of normative theories of law?

As to the first issue, according to Kelsen, legal science is possible because it refers to positive law, which one can identify by empirical means. However, Kelsen is not content with a purely descriptive approach to law, but wants to show how legal science is possible as a science of norms. In this respect, the “basic norm” is crucial. This chapter questions whether the mere presupposition of a basic norm is sufficient to establish the scientific character of legal doctrine.

As to the second issue, quite a number of theories have been advanced that purport to show how scientific, or at least rational, treatment of normative issues is possible without the dubious assumptions of traditional natural-law doctrines. I will discuss in particular Gustav Radbruch’s “methodological trialism” and the discourse theory of law as presented by Robert Alexy. From this discussion, I will then proceed to address the further question of the continued relevance of Kelsen’s critique of natural-law doctrine for legal science.