The modern state is built upon the principle that political power belongs to the people. Yet this principle has no uniform meaning. The very institutional structure of the modern state testifies to the plurality of understandings about the meaning, extent and implications of popular power. A quick look at modern European states reveals how each of their institutions is based upon a specific way of understanding and framing the power of the people. More strikingly, even within a single institution different conceptions of the people’s power play out simultaneously. As an example, it may suffice to think about how different the principle of popular power looks when invoked to justify the role of legislative assemblies and that of constitutional courts. The first institution is considered the forum where popular concerns and interests are elaborated, compromised upon and transformed into law by representatives.

Hannah Arendt’s theory of constituent power is radically different from Sieyès’s. Although in both cases constituent power offers a conceptualisation of popular power alternative to sovereignty, in Arendt’s case this alternative coincides withself-government. In Sieyès’s case, meanwhile, it entails the delegation of power to elected representatives. The differences and similarities between these two accounts show the interest and purpose of reconstructing the history of constituent power.

By looking at the language of constituent power and putting its uses into historical perspective, it becomes clear that, in the past two centuries, constituent power has been endowed with different, even opposite, meanings. It follows that the notion of pouvoir constituant has contributed in varying ways to the conceptualisation and institutionalisation of the principle of popular power within the framework of post-revolutionary European states.