Introduction

According to Article 16 of the defining document of the French Revolution, the Déclaration des droits de l’homme et du citoyen of 1789, a society in which the observance of the law is not assured, nor the separation of powers defined, has no constitution at all. This identification of the separation of powers with the constitution as such – an idea which has been commonplace in continental Europe since the late eighteenth century – may nowadays no longer be self-evident, but without doubt the separation of powers remains an important element of the ideal of constitutionalism and, hence, an important subject for constitutional scholarship .

Constitutional scholarship can approach the separation of powers in different ways. One approach is to adopt the positive legal method. The primary aim of this type of scholarship is to develop coherent legal doctrines by systematising positive law. From this perspective, the separation of powers appears as a legal doctrine; the result of the systematisation of the relevant corpus of positive law. One can also take a step back from positive law, and try to develop criteria on the basis of which positive law can be assessed and criticised or justified. This is the normative approach. The separation of powers , seen from this standpoint, is a set of normative ideas that aim to constitute and constrain political power.

This chapter discusses the relationship between both approaches, and argues that constitutional scholarship needs to incorporate a third and more encompassing approach which also takes into account the social and political context of the separation of powers. It proceeds on two levels. On the first level, it reviews The Three Branches by Christoph Möllers. Möllers explicitly tries to connect normative theory and constitutional scholarship. On the second level, it sketches the contours of an approach to the separation of powers, and to constitutions more generally, that aims to overcome the weaknesses of strictly positive and strictly normative approaches.

Möllers’ model of the separation of powers

The focus of this chapter is on methodology, but it seems appropriate to begin with a concise description of the outcome of Möllers’ approach, his model of the separation of powers . The basis of this model is the claim that public authority can only be legitimised as a form of self-determination (autonomy) of its subjects.