It is the professional duty of the judge to validate the law’s claim to validity, to sacrifice his own sense of the right to the authoritative comman… - Gustav Radbruch

Concepts such as legal subject and legal object, legal relation and legal wrong, and indeed the very concept of law itself, are not accidental possessions of several or all legal orders but are necessary prerequisites if any legal order is to be understood as legal.

Positivism, with its principle that ‘a law is a law’, has in fact rendered the German legal profession defenceless against statutes that are arbitrary and criminal. Positivism is, moreover, in and of itself wholly incapable of establishing the validity of statutes. It claims to have proved the validity of a statute simply by showing that the statute had sufficient power behind it to prevail. But while power may indeed serve as a basis for the ‘must’ of compulsion, it never serves as a basis for the ‘ought’ of obligation or for legal validity. Obligation and legal validity must be based, rather, on a value inherent in the statute.

Der Relativismus in der Rechtsphilosophie (1934).