(Mistakes #1, #2, #3)

Lots of prominent activities don’t immediately make pragmatic sense. I mean, they make sense in the sense that you want to do them, but not in the sense that you can give an explicit account of why you want to do them.

For instance, visiting family in holidays. For one thing, why do we even have holidays? For a few days, and not on other days? And why eat turkeys or champagne then, and not eat them the rest of the time? For another thing, why do we have families? And why see your family exactly that week? For those who like their families, is that the most convenient week? Or do people really need to coordinate in holding family dinner at the same time as people not in their families? For those who don’t like their families, why go to so much trouble to see people whose only special feature is that you were already forced to spend too much time with them decades ago? Also, why guess what someone else wants you to buy for them, while they spend the same amount on a guess for you? And why does everything have to be decorated in colors and sparklinesses that nobody during more sober times finds aesthetically pleasing?

As a young person, learning about the world, you can respond to this sort of thing in at least two ways. One option is to go along with the things. Perhaps you have great trust in society. Perhaps you don’t notice. Perhaps you have little curiosity or passion for improving the world. Perhaps you have heard of Chesterton’s fence.

Another option is to politely disregard any of the things that don’t make apparent sense, and redesign your life according to reason. Or rudely disregard any of the things that don’t make sense, if you don’t see the use in politeness! If you see no reason for eating dinner before dessert, or exchanging gifts, or doing well in school, then you just don’t do those things.

I have a soft spot for the social innovator, who sees the people needlessly toiling for senseless or forgotten goals and is willing to face social censure to make a better world. However I think young, intelligent people often make mistakes this way. It’s not clear to me that these mistakes can be avoided without giving up a valuable attitude, but my guess is that some can.

There are at least three closely related mistakes: breaking down Chesterton’s fence because you don’t know why it’s there; breaking down Chesterton’s fence because the owner doesn’t know why it is there; and breaking down Chesterton’s fence because the owner thinks it is there for reasons you know to be nonsense.

Chesterton’s fence

Chesterton’s fence is from a famous principle, which basically says ‘don’t take down fences unless you know why they were put up’. Or relatedly, don’t try to reform society while you don’t understand the reasons for its present behaviors. Most fences are put up not by crazy people, but by people who had some sensical motive. Even if you can’t see a bull, the fact that there is a fence there is suggestive.

Suppose you don’t understand why people go out for coffee instead of caramels. And suppose that you have an important date to organize which is likely to succeed if you don’t mess it up. One thing you might say is, ‘well, people go out for coffee a LOT, but I don’t see why coffee is especially good for dates, and caramels are cheaper and more delicious’. Then you might opt for the caramel date. This would be knocking down Chesterton’s fence.

When younger, I didn’t intellectually understand why people would shave their legs, or maintain their garden, or try at sports at school, or listen to their feelings if they weren’t obviously well-aligned, or get a job, or keep in much touch with their family once they had left home, or live in a building, or drink alcohol. So I either didn’t do these things, or assumed I would not later on, and so did not prepare for them. Even though I knew they were popular activities among humans. They aren’t obviously good activities, even now, but the point is that I didn’t really consider whether people have them for a reason that I didn’t understand. I quickly disregarded them because I didn’t understand them. And in fact I think I was often wrong to think they were worthless.

The basic mistake with Chesterton’s fence is either not taking the existence of a thing as evidence that someone has a reason for it, or inferring too little from that about whether it is good on your values.

Chesterton’s fence after contacting the caretaker

A more subtle mistake involves inquiring after people’s reasons for the inexplicable fences they protect, finding that can report none, then hastily trashing the fences. For instance, you ask your mother why it is important for you to have table manners, and she says ‘it just is’, so you stop doing it.

The problem with this is that people do lots of relatively useful things without having much explicit understanding of what they are doing or why. People pick most behaviors up from other people.

Sometimes someone once understood why the behavior was good, and intentionally constructed it for others to use. Like CBT or the Alexander Technique. Sometimes the thing wasn’t spread because someone understood it, but still it was experimentally checked, at least informally. Like drinking lemon and honey when you are sick, or making eye contact the right amount. Other times perhaps nobody ever understood or had the opportunity to check well for efficacy, but still social forces preferentially select for things that work, at least to some extent, for some goals. Arguably like religion, or being idealistic as a young person, or following your curiosity.

Even if never in history had anyone ever explicitly understood why table manners were important, their prevalence is decent evidence that you shouldn’t immediately abandon them.

Chesterton’s fence with a stupid sign

After realizing this potential mistake, there is another mistake you can make however. That is where you ask people the reason for a thing, and they give you a reason, and it’s a bad one—and then you’re allowed to break down the fence, right? If you know it was put there by some crazy person to keep the flying pigs at bay?

For instance, suppose you ask your math teacher why math is important, and she says that as an adult you will need to be able to add and subtract numbers when you are shopping or if you have a job in administration or science. And you know that people can have calculators, so adding skills are not really important. And you don’t care much about grocery price comparisons anyway, since your value of time is too high. And basically none of what you are doing is adding or subtracting anyway! It’s all trigonometry and calculus. Then you might reasonably infer that math is of no use to you. If this person who appears to be very invested in math—whose whole life is about encouraging you to do math—can’t come up with anything better than that, then surely you are safe to ignore math. (Loosely based on a true story).

The problem here is that often instead of doing reasonable things while being clueless about why (as discussed in the last section), people come up with reasons for the things they are doing, which are unrelated to the process that caused them to be doing the thing.

Perhaps the builder of the fence did it because something scares his dogs when they go up the hill. Whatever it is, he doesn’t want it coming down to his house. He has a correct intuition that a fence there would make him feel safer. He comes up with a story that the problem is flying pigs, which are fortunately respectful of fences. This is pretty much irrelevant. In this case the fence does indicate something you should watch out for.

The math teacher is teaching math because other forces recognized the value of math, recognized that she was good at both high school math and at teaching, and paid her enough to teach it. She doesn’t know about the details of how this came about, or why it was considered a good idea. However sometimes students ask her why they should do math. She ponders this, and reasonably thinks about when math comes up in her own life. She comes up with calculating things. She might also think of ‘being a math teacher’—an equally thrilling inducement to the ambitious student. Though the math teacher is in charge of the fence, she doesn’t automatically know why it is there. It feels like she should, which may compel her to search for reasons, but the reasons have had somewhere between seconds and hours of thought applied to them, while the behavior itself underwent a more thorough optimization process.


This makes things hard, because when are you allowed to just write off things as not valuable? If someone looks you straight in the eye and says ‘I’m clashing these pots together because aliens’, do you have to reserve substantial credence that they are doing it for a good reason?

I think the main point is that in these cases you need to have actual beliefs about what is going on, and decide based on the apparent situation. You don’t get to just blanket disregard things because you don’t understand them, because its proponents don’t understand them, or because its proponents claim to do them for bad reasons. But you can update somewhat toward thinking the things are useless, and perhaps a lot.

An important part of figuring out when you should disregard inexplicable behaviors is understanding where the behavior came from. If your pot-clashing friend feels compelled to clash pots because it makes him feel less anxious about the aliens, then probably it is worth it for him, for entirely non-alien reasons. There is even some chance that it would also be useful in relieving your own anxieties about other things. If your friend clashes pots because he read online that this is the anti-alien-club sanctioned way to fend off aliens, then there are fewer models on which clashing pots is advantageous for either of you.

Sometimes understanding where behaviors come from will tell you that a behavior is well-honed, but not for goals you have, so this understanding allows you to break down fences you might have otherwise respected. For instance, if you are a teetotaler, and your best guess is that the excitement about festival X is closely related to its cheap and delicious booze, then you can infer that the festival is an unusually poor fit for you, even if nobody can explain well to you why they love it.


In general, I propose acting like a person who takes seriously the possibility that there is a bull in the paddock, rather than someone who is obliged to do a checking ritual before they are allowed to gleefully smash down the fence. Then follow the usual epistemological procedures for determining what statements are true and what actions are good.

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