Introduction

The image of constitutions that derives from a socio-legal perspective assumes a profoundly different standpoint. A constitution can be considered a milestone in the internal evolution of a legal order, as well as in the external processes of the legitimation of law. The relations between formal rationality and the capitalist economy, which should be reconstructed referring to the constitutional principle of the freedom of contract, can actually be limited in the most advanced Western legal orders and in their constitutions by apparently contrasting perspective. From a socio-legal perspective, the legal order is presented as compatible with other organised social norms. According to Luhmann, legal structures are connected with processes of normative experience, generalisation and abstraction. The selective inclusion of external elements into social systems is so important for Luhmann that he elaborates specific concepts, so as to designate different ways of mapping the borders of the legal system.