We must not believe that, because we have learned to make laws deliberately, all laws must be deliberately made by some human agency. Rather, a group of men can form a society capable of making laws because they already share common beliefs which make discussion and persuasion possible and to which the articulated rules must conform in order to be accepted as legitimate.
From this it follows that no person or body of persons has complete freedom to impose upon the rest whatever laws it likes. The contrary view that underlies the Hobbesian conception of sovereignty (and the legal positivism deriving from it) springs from a false rationalism that conceives of an autonomous and self- determining reason and overlooks the fact that all rational thought moves within a non- rational framework of beliefs and institutions.
Constitutionalism means that all power rests on the understanding that it will be exercised according to commonly accepted principles, that the persons on whom power is conferred are selected because it is thought that they are most likely to do what is right, not in order that whatever they do should be right.
It rests, in the last resort, on the understanding that power is ultimately not a physical fact but a state of opinion which makes people obey. Only a demagogue can represent as “antidemocratic” the limitations which long-term decisions and the general principles held by the people impose upon the power of temporary majorities. These limitations were conceived to protect the people against those to whom they must give power, and they are the only means by which the people can determine the general character of the order under which they will live. It is inevitable that, by accepting general principles, they will tie their hands as far as particular issues are concerned.
For only by refraining from measures which they would not wish to be used on themselves can the members of a majority forestall the adoption of such measures when they are in a minority. A commitment to long-term principles, in fact, gives the people more control over the general nature of the political order than they would possess if its character were to be determined solely by successive decisions of particular issues.
A free society certainly needs permanent means of restricting the powers of government, no matter what the particular objective of the moment may be. And the Constitution which the new American nation was to give itself was definitely meant not merely as a regulation of the derivation of power but as a constitution of liberty, a constitution that would protect the individual against all arbitrary coercion.