The main stream of legal theory tends to incorporate unwritten principles into the law. Weighing of principles plays a great role in legal argumentation, inter alia in statutory interpretation. A weighing and balancing of principles and other prima facie reasons is a jump. The inference is not conclusive.To deal with defeasibility and weighing, a jurist needs both the belief-revision logic and the nonmonotonic logic. The systems of nonmonotonic logic included in the present volume provide logical tools enabling one to speak (...) precisely about various kinds of rules about rules, dealing with such things as applicability of rules, what is assumed by rules, priority between rules and the burden of proof. Nonmonotonic logic is an example of an extension of the domain of logic. But the more far-reaching the extension is, the greater problems it meets. It seems impossible to make logical reconstruction of the totality of legal argumentation. (shrink)

The author analyzes the relations between truth and law starting from the distinction between practical and theoretical spheres. He shows, first, how moral and legal statements and reasoning are connected with an operation of weighing and balancing different values and principles and how this operation is ultimately based on personal and intuitive preferences and feeling. The criteria developed by the theoretical sciences to define truth (coherence, consensus and pragmatic success) can only be translated into practical statements as criteria of correctness (...) because we cannot affirm that a norm or value statement is true or false. The three criteria become interrelated indices of correctness: They are criteria for rational discourse. (shrink)