Propositions of law are based upon normative judgement. The interpretation and application of legal provisions rest upon a judgement that determines which weight must be attributed to some point of view or perspective. In this respect, legal theory has a normative character. Its normative character does not preclude legal theory from being a scientific discipline. The scientific character of legal theory is not located in the possibility of testing the correctness of its theories. Rather, legal theory owes it scientific character to the shared standards of production and evaluation of legal arguments: the grammar of justice.