My scientific authorship is characterized by my interest in legal-theoretical problems - specifically, in the role of basic assumptions in the law. Thus, my doctoral dissertation constitutes a critical confrontation with Hans Kelsen’s type of legal positivism, and in particular his doctrine of the basic norm (“Why Grundnorm? A Treatise on the Implications of Kelsen’s Doctrine”. Law and Philosophy Library vol. 58, Kluwer Law International, 2002, 245 pp.). In this treatise I contend, firstly, that the “presupposition” of the basic norm, on a certain reading of Kelsen’s doctrine, can be understood as constituting a normative source of positive law; and, secondly, that this reading of Kelsen admits of addressing the issue of the (formal) legitimacy of supra-national and directly applicable rules and other norms.
My interest in Kelsen’s legal theory prompted me to further investigate into various aspects of his concept of the basic norm and, what is more, into the descriptive-normative nature of utterances made in specifically legal speech-situations. These studies resulted in a number of articles, among which can be mentioned ‘Presupposing the Basic Norm’, in 14 RATIO JURIS (2001), pp.143-75; ’Descriptive Normativity: Kelsen’s Sollsatz in the Light of Some Later Theories’, in 5 ASSOCIATIONS (2001), pp.71-94; and ‘The Modality of Kelsen’s Sollsatz’, in RECHTSTHEORIE, Beiheft 21 (2005), pp.167-78.

As a tribute to Kelsen, I translated his major work Reine Rechtslehre, 2nd Edn. (Wien: Franz Deuticke, 1960) into the Swedish language. The translation was published, in 2008, by Bokförlaget Thales, Stockholm.