A positivist foundation of the legal system: Popular sovereignty as a social convention or social rule

A recurring question in legal theory regards the basis of the legal system. One possible answer is that it emanates from the people, as captured in the concept of popular sovereignty. This concept plays a role in many contexts ranging from political philosophy to constitutional law. However, it is not always clear what popular sovereignty means and how state power can be said to emanate from the people. This paper seeks to remedy this. In order to do so, it sketches a conception of popular sovereignty that explains how and in what way state power emanates from the people. This conception, following Hampton’s account of political authority, bases state power on a social convention. However, an investigation into the nature of social conventions, drawing insights from legal theory and philosophy more generally, reveals that this conceptualisation is not accurate. Legal theory provides an alternative in the form of social rules, and this paper ultimately argues for a conception of popular sovereignty as the power of the people to constitute and maintain state power via the acceptance of and compliance with a social rule to this effect. This paper pursues two aims: firstly, it aims to develop a positivist and explanatory conception of popular sovereignty, which operationalises the concept for political scientists, constitutional (and European Union) lawyers, legal positivists and (legal) sociologists, linking political philosophy with legal theory. Secondly, it aims to investigate potential issues surrounding the use of social conventions in legal positivism, and to propose social rules as an alternative for some cases.