Introduction

One could not agree more with Christoph Möllers about the distance that has grown between political theory and constitutional law and about the need and the promise of bringing them together again in studies such as that of the separation of powers. And it can be done so well! Both political theory and law are historic disciplines , which essentially deal with the creation and development of historic facts (including legal facts), of texts, of notions and ideas. This explains why they mesh so much better than, say, law and political science. Science is a numerical exercise, one of numbers and figures. Between the moral basis of law and the numerical basis of political science, there is a difficult relationship. Political theory on the other hand, is about notions and concepts, in their historic development, just like the law is, in part.

I also sympathise fully with his attempt to bring the legal and the political theory angles on separation of powers under a common purpose, that of freedom or autonomy. Again, this opens a singular and vital span, between individual and collective freedom/autonomy.

As Möllers shows, the span between these autonomies, individual and collective, provides an effective screen for the study of the trias politica in various situations of accomplished constitutional systems: states. There indeed the motif of autonomy is dominant.

Less convinced, however, I am by its application beyond the state, notably to the European Union. In that context of the Union I think this span is too narrow and the upshot of his analysis consequently somewhat disappointing. The trias motif has a wider power, including but going beyond that of furthering autonomies.

What explains the triad's singular power and its enduring appeal, in situations of public authority, between all its different versions of separation of powers as developed over time and across the globe? Indeed, it provides for lasting autonomies and even allows for partially opposed autonomies. But more generally, it opens up situations and brings their elements into play. It does so more durably, for one thing, than a duality. Much more than a duality, the trinity or trias allows a public authority to cope with, or even enter into, evolution.