Introduction

To appreciate how Luhmann distinctively approached law, we have to consider how law understands itself. As he says in the revised conclusion to the second edition of A Sociological Theory of Law:

Similarly, legal theories have unfailingly attempted to account for the unity and autonomy of law. They ask themselves questions about what gives law its unity and distinguishes it from the rest of society. Even those legal theories which challenge claims that law exhibits unity or autonomy take such accounts seriously, if only to refute them. However, within legal theory, the principal attempts to explicate law as unified and autonomous have not offered themselves as sociological explanations, relying instead on forms of philosophical analysis. The two leading twentieth-century legal theorists offering such accounts of law as, and operating within, separate autonomous systems are Hans Kelsen and H.L.A. Hart. For Kelsen, law is, or operates within, a system of positive (non-moral) norms which authorise coercive action, unified by a constitution whose own authority is presupposed. Sociology is not relevant or necessary for the identification of this system. The empirical requirement is limited to a sufficient congruence between the norms authorising coercion and their occurrence to justify the conclusion that the identified system of norms is generally effective. For Hart, law’s existence as operating within a system of positive (non-moral) rules is achieved through the adherence by officials to a common standard when identifying those ‘legal’ rules: the rule of recognition. This standard is a socio-psychological fact, evidenced by the limited but common sources of law acknowledged by legal officials. Hart claimed that his approach is an example of ‘descriptive sociology’, but its sociological content is extremely constrained.