- What is to be understood by 'rational legal argument'? To what extent can legal reasoning be rational? Is the demand for rationality in legal affairs justified? And what are the criteria of rationality in legal reasoning? The answer to these questions is not only of interest to legal theorists and philosophers of law. They are pressing issues for practicing lawyers, and a matter of concern for every citizen active in the public arena. Not only the standing of academic law as a scientific discipline, but also the legitimacy of judicial decisions depends on the possibility of rational legal argumentation.