‘Successful constitutions and institutions’, says Ian Gilmour (Inside Right: A Study of Conservatism (1978), p 70), ‘are not mere pieces of machinery. If they work, it is because of the ideas and beliefs of those who try to work them.’ The British constitution, having evolved over centuries, does not embody any single constitutional theory. It is the product of a long period of kingly rule, parliamentary struggle, revolution, many concessions and compromises, a slow growth of custom, the making and breaking and alteration of many laws. Although we lack a general theory of the constitution, there has come down to us an idea of constitutionalism – of a constitutional order which acknowledges the necessary power of government while placing conditions and limits upon its exercise. The British version of constitutionalism has been shaped by a number of leading ideas or principles: some of these have crystallised as rules or doctrines of the constitution; others have influenced constitutional thought or have gained currency as explanations or justifications of particular features of the constitution. In this chapter we shall consider some of these commanding ideas or doctrines and their place in the modern constitution. We start with democracy and then move on to consider the sovereignty of Parliament, the rule of law and the separation of powers. It will appear that, at times, there is a conflict, or tension, between these ideas; between democracy, for instance, and parliamentary sovereignty, or between sovereignty and the rule of law. A good deal of contemporary constitutional analysis is concerned with how such conflicts, or tensions, should be resolved and worked out. (For an engaging critique, see Murkens, ‘The quest for constitutionalism in UK public law discourse’ (2009) 29 OJLS 427.)

Democracy and the constitution

Democracy is not to be taken for granted. Neither is its contemporary acceptance as the only form of government able to claim legitimacy to rule. As John Dunn asks in his account of the history of democracy, Setting the People Free: The Story of Democracy (2005), pp 13, 15:

Democracy came late to the British constitution. Much of our constitutional architecture was constructed at a time when to accuse someone of harbouring democratic sympathies was a grave political insult. This is not to say that democracy came late to Britain in comparison with other countries. But it is to say that several key elements of the British constitution predate the emergence of democracy as an accepted form of government. Anthony King puts the point well (The British Constitution (2007), p 249):

Nonetheless, democracy deserves to be treated as the first of our constitutional themes since the working assumption of all the principal actors on the constitutional stage, even those who (like the monarch and the House of Lords) are not themselves democratically elected, is that Britain is, and ought to consider itself as, a modern democracy. Even if the assumption is sometimes misplaced or over-stated, it is impossible to understand the way the contemporary British constitution works without taking on board this basic working assumption. Equally, however, like all assumptions, it is rebuttable. On no account could today’s British constitutional order accurately be described as entirely or unambiguously democratic. (Valuable introductions to the idea of democracy abound. Among the better ones, see R Dahl, On Democracy (1998) and B Crick, Democracy: A Very Short Introduction (2002).)