(This is an archived page, from the Patterns of Power Edition 3 book. Current versions are at book contents).
Who is in charge of society, who or what is sovereign? H.L.A. Hart’s answer, in The Concept of Law, invokes the supremacy of the law:
"The rules are constitutive of the sovereign, not merely things which we should have to mention in a description of the habits of obedience to the sovereign.” [p. 76]
This amounts to saying that a society defines its governance by its Constitution. Everyone, including the government and the judiciary, is subject to it. Hart referred to it as a system of “secondary rules” that "specify the ways in which the primary rules may be conclusively ascertained, introduced, eliminated, varied, and the fact of their violation conclusively determined” [p. 94]. It is the basis for the authority and the legitimacy of sovereign power.
In Hart's definition, which is also the usage in this book, the secondary rules control the maintenance of the entire governance structure – including economic regulations, the legal system and the political system. The separation of these powers is a useful safeguard against oppression, as discussed later (5.2.8).
The secondary rules for the maintenance of national laws are mainly a constitutional matter for the country concerned, but they are constrained by international agreements that the country has entered into – so sovereignty is affected, as described earlier (2.8.3). The British vote to leave the EU, in a 'Brexit', was partly driven by spurious arguments over sovereignty – as described in The campaign for a Brexit blog post.
There is a procedure for amending most Constitutions – which normally requires a more substantial majority than is the case for primary legislation, so they cannot be changed as easily. The British Constitution, however, is unwritten and flexible; it has been put under strain recently by Brexit, in what The Economist described as Britain's constitutional time-bomb: “The constitution is unclear on whether the executive or Parliament should prevail” and Brexit is “threatening the integrity of the union”.
Power can flow up or down (2.8.2). It can be delegated downwards to allow regional and local control, so that legislation can be carried out at the appropriate level whilst allowing some difficult cases to be referred upwards for resolution. The resulting subsidiarity of legal control is described in more detail later (5.3.2).