Starting Point
Legal norms, like norms in general, can be divided into several subgroups, depending on their deontic qualifications, as follows:
1. prescriptions, including commands, prohibitions and permissions,
2.
norms of competence, and3. legal definitions.
This division is not a key issue as far as the present study is concerned. The need and the structure of interpretation is the same independent of the norm category. Instead, another dichotomy, that is, the division between rules and principles is significant because it is reflected in the method followed in DSL.
The concept of principle has been at the kernel of modern jurisprudence (For example: Alexy 1985,15,1989,4,243,2007,20; Aarnio, 1990,180; Avila 2006,29; Dworkin 1977b, passim, 1981, passim; MacCormick 1978a, 155; Peczenik 1989, 74; Raz 1972, 823, 1975,49). This results, at least partially, from the growing interest in human rights, but not only from that. In the statutory law systems in the Nordic countries, for instance, the open texture norms have gained more and more footing. The idea of strict rules solving each individual case does not function in a dynamic, quickly changing society. There has been and is a societal need for more elastic legal norms. Principles are one type of those norms. In recent jurisprudence, the focus has especially been on the structure and the role of principles.