On the basis of a new, critical methodology of public law, Kelsen and his students sought to come up with an “objective” architecture of international law. One factor that was particularly influential for Kelsen's theory of international law was his critical engagement with that of Georg Jellinek and the German Staatswillenspositivismus [state-centered positivism]. Kelsen had outlined his fundamental critique of Jellinek's theory of the state already in his Hauptprobleme der Staatsrechtslehre [Main Problems in the Theory of Public Law], and he carried it further in his first monograph on international law, written during the First World War, Das Problem der Souveränität und die Theorie des Völkerrechts [The Problem of Sovereignty and the Theory of International Law]. It is remarkable how deeply Kelsen, in this fundamental work, was influenced by the Wolffian–Kaltenbornian construction of an “objective” international law, combining it with his new methodological approach to public law. In that sense, this monograph, a foundational work for the Vienna School's theory of international law, can be seen as picking up on Kaltenborn's work while turning away emphatically from the international law theories of Georg Jellinek.

A new methodological tool kit

Kelsen's Main Problems in the Theory of Public Law and The Problem of Sovereignty sought to place the traditional doctrine of state and international law on a new methodological foundation. In the final analysis, Kelsen was concerned with nothing less than establishing legal scholarship as an autonomous “scientific” field.