Did you know that the UK has no single constitutional document? I think what this helps us understand is the distinction between what Hayek called “Law” versus what Hayek called “Legislation.” Legislation can be loosely thought as something which has been consciously written down in a statutory manner by a legitimate elected body. But of course, just because something is in the statute book does not imply that it is going to be respected. My “favorite” example might be the way the Commerce Clause of the US Constitution has been loosened to allow Congress to regulate anything it wants, even if such commerce is wholly confined to within a particular state. So while it may appear that “legislation” indicates that wintercow growing barley for his own consumption in his own backyard is exempt from federal regulation of his activities (so long as I am not violating property rights of others) the “law” is such that we in fact do allow such regulation.
So we ignore the written statutes. That which is law, the body of formal and informal rules that are actually binding in civil society, is an institutional feature and not a statutory one. It is driven by culture, custom and precedent. So, FDR notwithstanding, prior to the 22nd Amendment, the law in the US was that no Executive of the Federal Government should serve more than two terms in office. Similarly, if you show up at a cafeteria and prior to getting your food slap your backpack down on a chair, that chair is “yours” for a reasonable duration of time despite there being no statute I am aware of that says that people who place jackets and bags on cafeteria chairs get to claim those seats. But we respect that tradition and custom. In other words, what is law is actually the outcome of emergent and spontaneous processes resulting from millions of individual interactions with one another and the institutional framework such decisions are operating in. How those “laws” come to be respected is hard to explain, and I am not sure it is adequate in a blog post to attempt it here.
The deeper point is that there are “higher powers” seemingly always and everywhere that reasonable human beings submit to. Those of us who nonetheless like the Constitution and what is stands for are not actually appealing to the document itself as a binding constraint on our behavior in collective action problems. The document, in my view, reflects the evolution of what had already been applied as “law” for the centuries leading up to its creation. This tradition goes back at least to Magna Carta and is embodied in centuries of exchanges and struggles between those in authority and those not in authority about the proper exercise of coercive power and the importance of creating feedback within the political process that enables the authorities to both exercise their necessary protective functions but to limit their exercise of what Acemoglu and Robinson call their extractive functions.
That the UK has no constitution therefore does not imply that the country is awash in chaos. Nor does it mean that it does not have a complete and clear body of law by which its people are “governed.” There are not only important customs and culture which drive behavior, but also a very long-standing tradition of reliance on decisions in past disputes to help us understand what is and what is not acceptable behavior. This would be a nice launching off point on the “need” for us to be able to appeal to some higher authority to govern our behavior, whether it be a spirit that is codified by a document, or something else. Perhaps over beers.