This chapter begins with the central claims of Hans Kelsen's Pure Theory of Law with regard to law and State. Kelsen's Pure Theory of Law starts out from the fundamental distinction between ‘Is’ and ‘ought’. The validity of a norm is an ought and not an is', according to Kelsen. Kelsen's Pure Theory of Law can also be seen as some kind of negative answer to Georg Jellinek's Allgemeine Staatslehre. In contrast, Jellinek's approach avoids a purely legal conception of the State and law. Jellinek and Kelsen conceived the relationship between law and the State from distinct methodological orientations. Jellinek, ethical and legal norms are not separable within a society in as much as law has always been oriented towards relevant concepts of ethics or morality. Jellinek's concept of validity in a sociological or psychological sense could help to identify content for a State under the rule of law beyond the doctrines of natural law.