Pave the muddy paths

Monday, February 4th, 2019

We often think of “law” and “legislation” as synonyms, Mike Munger notes, but Hayek argued otherwise:

Habits that are shared might be called “customs,” informal rules that might be written down nowhere. These are agreements, in the sense that we all agree that is the way we do things, even though we never actually sat down and signed anything.

A while back I wrote about the Pittsburgh left turn as an example of such a custom. It is important that the habit of waiting for someone to turn left in front of you be “agreed” on, in the sense that the expectation is widely shared — and met — because otherwise it wouldn’t be effective in making traffic move faster. These customs can come to govern behavior, however, precisely because they shape expectations, and violating expectations may be expensive or dangerous.

Those customs, if they consistently lead to useful outcomes, are “laws.” They are discoverable by experience and emerge in the form of traditions. But it is useful to write them down so that they can be enforced more effectively and can be easily learned by new generations. Laws that are written down are rules, commands, and prohibitions we call “legislation.”

The problem is that legislation need not arise from law at all.

Hayek was rightly concerned about the conceit that experts know what is best for everyone else:

I often illustrate this with what I call the Hayek Sidewalk Plan. Imagine that a new university has been built, and you are on the committee charged with laying out the sidewalks. What would you do?

You might walk around, look at aerial maps of the campus, and draw lines to try to guess where people will want to walk. Or you might want to have a purely aesthetic conception of the problem, and put the sidewalks in places or in patterns that are pleasing to the eye as you look out the windows of the administration building.

But all of that is legislation. No individual, or small committee of individuals, could possibly have enough information or foresight to be able to know in advance where people are going to want to walk. After all, universities are peopled by broadly diverse groups, with heterogeneous plans and purposes. People are often willing to walk on the sidewalks, if that serves their purpose at that point. But you probably don’t want to build a sidewalk from every doorway to every other doorway on the campus.

What would a law look like, in this setting? No one person, after all, has any effect walking on the grass, and all the different plans and purposes, taken one at a time, contain no information that you can use. But there is a physical manifestation of the aggregation of all these plans and purposes working themselves out over time. I don’t intend to make a path, and neither do you. But if enough of us, over time, find it useful to walk in the same place to accomplish our own idiosyncratic purposes, a visible record of the shared pattern emerges: a muddy path.

So, the law for the Hayek Sidewalk Plan committee will be discoverable if we adjourn for six months or so and then have a drone take some overhead photographs. It is clear now where people, acting as individuals but observable together in the shared result called a muddy path, want the sidewalks to be placed. And the task of the committee is simply to “legislate” by paving the muddy paths.

If we think of the process of discovering law as “looking for the muddy paths,” and legislation as “paving the muddy paths,” we have a simple but quite powerful way of thinking about the rule of law.


  1. Albion says:

    Near where I live you can see (from a major road I sometimes drive on) a footpath running diagonally across a field from lower corner up a slight incline to a gate at the far top corner. This has been used many times, perhaps to the annoyance of the farmer or maybe the landowner was the first to make the initial track.

    What always amuses me is that about two-thirds the way along this well-worn path, there is an unnecessary kink in the line of the path. For no obvious reason (no tree or water hole or rock) it bends a little to one side and after a few yards resumes the ‘natural’ path of the shortest route between the two points.

    But clearly every single person who followed the path over the years has never stepped off the worn way: every user has followed the path (unnecessary kink and all) without question. Maybe tradition dictates you follow what was laid down, or maybe no one finds the extra steps required any sort of issue.

    It would take a rebel to make a newer, straighter path.

  2. Harry Jones says:

    Whenever I see something like that, I just walk the way that makes sense to me – carefully, in case there’s some reason for the detour I don’t know about.

    Having the independence of mind to make your own paths is an advantage, provided you go about it prudently. Rebels are a dime a dozen, but a smart rebel is another thing. Smart rebels make breakthroughs. Smart rebels advance human civilization.

  3. Graham says:


    Every time I encounter someone rebelling I wonder if they might be in the less than one percent fraction or the dime a dozen fraction. You can’t always be confident in advance.

    Though I’m also the sort that wants to protect traditions from utilitarians for their own sake. Sometimes it’s your reason — which was Chesterton’s. He wrote something along the lines of even if you find an isolated wall with no obvious purpose, you leave it alone until you can explain why it was built in the first place.

    That’s a pretty extreme example. Many would say that if one can ascertain no current utility, it should not be necessary to determine its original utility and prove that it no longer exists. I sympathize and would probably say that’s how things should normally work, but we have lived through an age in which too many things have demonstrated Chesterton’s wisdom, and too many others have made what, for me, is the wider error of prioritizing utility at all over other factors. I’d probably say an ancient wall in the middle of a field should stay for its own sake, unless you actually have a genuine, overriding modern utility to serve by knocking it down.

    SO with the path example, I’d probably walk the worn path and take a curious look at the straight route a few times. The loss of time and effort is too trivial to automatically cut a new path. But I’d keep the option open for consideration.

    In practice, of course, we’ve all worn paths on literal grass countless times, so there’s room for rebellion at last.

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