
Chesterton’s Fence: A Lesson in Second Order Thinking - imartin2k
https://fs.blog/2020/03/chestertons-fence/
======
alan-crowe
It troubles me that Chesterton charges the man who would tear down the fence
with a duty: "Go away and think. Then, when you can come back and tell me that
you do see the use of it, I may allow you to destroy it."

I see the charm of Chesterton's favourite rhetorical judo. But we have learned
many hard lessons about the cost of losing the documentation. We should charge
the man with the duty of looking up the purpose of the fence in the archive,
and finding the date that the purpose ceased to hold.

We should go further and invent the _conservatism of the archive_. When we
contemplate changing the rules of society, the archive needs to contain more
than just the justification of the new rules, analogous to the purpose of the
fence. The defeated opposition must also have their place in the records.

Write down your rules. Write down why you have chosen them. Write down what
your critics say will go wrong. Write down what your critics say we should do
instead. Keep it all safe in the archive for 100 years.

When things don't go according to plan, dig through the archive. Did you stick
to your rules? Really? In a way that is faithful to the reasons why they were
supposed to work? What about the critics? Did things go wrong in the way that
they predicted, or in some other way?

If the critics predicted the exact way that things would go wrong, they win.
Dig out their suggestions and give them a try. If the critics predicted
different screw-ups than actually happened, cry. Nobody knows anything. But at
least you have an archive. What it was like. What people thought. How it
actually turned out. That is a basis for working out what to do next.

~~~
CogitoCogito
I think one of the less appreciated corollaries of Chesterton's line of
thought, is that we should be wary of building fences in the first place. In
programming, I think that abstraction should be avoided until the need for it
arises. On the first pass (or two or three), a program should be written
clearly and simply and only do what it needs to. Working with many
abstractions in software can be very difficult later and it can be especially
hard if it turns out the original abstractions are the wrong ones in
hindsight. Because later Chesterton will apply and people will try to shoehorn
their new work into the existing abstractions instead of taking a step back
and realizing that they would never be there in that form if the abstractions
were designed today.

There's no silver bullet with anything in life, but something to keep in mind.

~~~
onion2k
_I think one of the less appreciated corollaries of Chesterton 's line of
thought, is that we should be wary of building fences in the first place_

Would that change anything?

Assume the original author did think about whether it was necessary, and they
thought it was. You know have to think whether the fence is still necessary.

Now assume the original author didn't think. You still have to think about
whether the fence is necessary.

Nothing has changed.

~~~
CogitoCogito
Would it change anything? Uh...of course? If you build fewer fences it will
result in fewer fences. I'm not really sure what confuses you.

Unless your point is whether not building as many fences now will save you
from Chesterton's reasoning for any fences already built, then well of course
not.

Changing the metaphor, I'm just saying that you should consider stretching to
avoid future injury. Of course that doesn't save you from dealing with
injuries that have resulted due to a lack of stretching in the past.

~~~
onion2k
_If you build fewer fences it will result in fewer fences._

Chesterton's Fence only applies to removing existing fences, so it obviously
only applies to fences that already exist. It doesn't say anything about
whether or not you should build the fence in the first place.

~~~
CogitoCogito
> Chesterton's Fence only applies to removing existing fences, so it obviously
> only applies to fences that already exist. It doesn't say anything about
> whether or not you should build the fence in the first place.

I'm also really having trouble understanding why it's so complicated for you
to understand. Chesterton's fence says you shouldn't remove a fence until you
understand why it's there. Ergo the removal of a fence requires effort. Ergo
you should not put up fences unless provide actual value, because they will
require effort to remove later.

Regardless, Chesterton's fence is a principle with whatever wisdom one chooses
to draw from it. I guess if you disagree with me it doesn't really matter.

------
dwheeler
It's a fun essay, but because of the way it's written, a reader could easily
confuse "second order thinking" with "understand why a decision was made
before planning on changing it." I think the _author_ distinguishes them, but
the reader might not notice the distinction because of how it's written.

Here's how I would distinguish these two ideas (hopefully the author would
agree, but no guarantees):

* Second-order thinking is the ability to understand the impacts of the impacts of a change. If you're playing a chess game, looking only 1 move ahead (just looking at the impacts) means you'll lose against even a mediocre player. The better you can foresee later impacts, the better the decisions are likely to be. In the real world, there aren't a limited number of moves and no one knows all state, so you can't really look ahead multiple stages for all possibilities. Nevertheless, _trying_ is really important. The close says: "The first step before modifying an aspect of a system is to understand it. Observe it in full. Note how it interconnects with other aspects, including ones that might not be linked to you personally. Learn how it works, and then propose your change."

* "Chesterton's Fence" is a useful rule-of-thumb to get at least a sliver of second-order thinking. Basically, if someone else did something, make sure you understand why they bothered to do it before you undo it. That exercise will help give you a bigger picture & may reveal something important that you hadn't considered.

At least, I think those are some of the points the author is trying to get
across. If I've totally misunderstood things, I'm sure someone here will
correct me :-).

~~~
leephillips
This is exactly what I was thinking. I was intrigued by this idea of second
order thinking, but after finishing the article I didn't think that I had seen
an example of it.

------
hinkley
Someone was asking the other day what other readers use git history for over
the long term.

We use it for differentiating Chesterton's Fence from cargo culting and
arbitrary decisions.

You go back and find out from context that code was there to fix a bug or
implement a requirement that no longer exists, you remove the code. You find
out the person just liked to write code this way, you remove the code.

You find out that it was to solve a problem on FreeBSD or old Docker versions
or for your biggest customer, you leave the code, or reimplement the fix.

Nobody will remember why they did something, but you can often figure it out
from the shape of the commit and its siblings.

~~~
humanrebar
It's worth mentioning that cargo culting and arbitrary decision-making aren't
necessarily bad from the perspective of the Chesteron's Fence thought
experiment.

It may not matter if people who left the fence alone even knew why they were
doing it. What matters is whether the fence serves an important purpose. Of
course, there is wisdom in finding out exact reasons, but sometimes the
reasons aren't consciously chosen. There are such things as emergent and
unintended benefits.

------
charlieflowers
Am I the only one that finds it irritating that the article starts out saying
the same thing over and over?

First as a parable, then a restatement, then a bold restatement? Why not
repeat it again, but underline it this time?

I feel like an 8th grader did it for homework and tried to stretch it to the
maximum amount of words.

~~~
charlieflowers
Just to clarify ... it is the start of the article that I’m criticizing. Once
it gets going it makes some decent points.

~~~
andrewflnr
Interesting. It was actually the back half where I thought it was getting
repetitive.

------
raz32dust
Is that really what second order thinking is? I wanted to see some examples of
successfully thinking through consequences of consequences, but the examples
seem to be only going one level deep. For example in the CFO in a startup
example, I would think that old employees jumping ship when snacks are made
paid is a first-order impact - just that the CFO did not think through all
possible connotations. I would think second order thinking would be thinking
about what is the impact of the savings itself, and realizing that it might
not be worth it.

~~~
sokoloff
From the CFO’s perspective, the cost-savings is the first-order impact. Then
unhappiness and possible attrition is a second-order impact.

Side story: Was at a place a long time ago where free soft drinks were made no
longer available. First day of the new policy, email to all staff announcing
the change. An hour later, one of the stronger engineers sends an email to all
local staff announcing he’s thirsty and going to the supermarket to buy some
soft drinks. Invites all engineers along in case anyone else is thirsty.
Several respond (on thread) that they are also thirsty. About 90 minutes
later, emailed status report of the successful 5-person mission to the
supermarket is sent and proposing a rotating schedule of supermarket trips.
The next day, email announcing the return of free soft drinks is read by all.
:)

------
wwarner
And the gate shall remain, and henceforth it shall be called "technical debt."

------
sandoooo
The thing about second-order thinking is that once you recognize it, you start
seeing the lack of it everywhere. And, congratulations, you're now struck by
the urge to fix it somehow.

This sucks, by the way. You'd probably be happier and have more friends if you
didn't notice. Once the screaming stops, somebody has to tip the pee out of
the shoe. And that's you now, peeman.

------
jameshart
Does the author really think that the creators of what he calls 'supposedly
hierarchy-free companies' don't meet Chesterton's bar? That they swept away
hierarchy without having first thought about why hierarchy exists in the first
place?

Or does he perhaps suspect that they haven't thought about it _enough_? After
all, they can't have truly understood why hierarchies were first instituted,
because they have failed to see the benefits he so obviously believes
hierarchical organization has.

See, this is the problem with Chesterton's fence. You tell the reformer to go
away and think about why the fence is there, and then she comes back and tells
you the fence was put there to keep her out. And you say 'ah, poor child, you
still don't really understand why the fence is there.'

Sometimes the burden of proof needs to be the other way round.

We're ripping out that fence. And if someone wants to keep it, they need to go
away and think and, if they can tell us why that fence needs to continue to
exist, only then can they stop us.

~~~
xamuel
Whoops. You just removed the fence which was put in place thousands of years
ago to contain radioactive waste with a million-year half-life. You couldn't
read the warning signs since they were written in an ancient long-forgotten
script. So you assumed it must be unimportant.

~~~
Firadeoclus
Luckily, material with a million-year half-life would be barely radioactive.

And what's the alternative? To assume that every barrier in existence we can't
explain is important and must therefore be maintained forever?

~~~
xamuel
One alternative would be for you to follow the prescription, "find out why the
fence was put there, then I may allow you to remove it". Investigate what's on
the other side of the fence, without tearing it down (this might involve
experimentally re-discovering the theory of radiation, depending on the
current state of mankind's knowledge). Then go back to the authority and
report that the fence seems to be there to contain radioactive waste with a
million-year half-life. Armed with this information, the authority will be in
a better position to determine whether or not to allow you to tear down the
fence.

------
clairity
> "Take the case of supposedly hierarchy-free companies...."

>

> "Someone needs to make decisions and be held responsible for their
> consequences. During times of stress or disorganization, people naturally
> tend to look to leaders for direction."

it's ironic that the author misses the first-order purpose of hierarchies,
which is to solve the coordination problem, not simply to have a leader
barking orders.

we've also (re-)learned a lot about the second-order effects of allowing power
to centralize in organizations as a result. yes, hierarchies can be useful,
and yes, hierarchies are highly problematic. so yes, we should be looking at
better models of coordination.

seems like they didn't think through any order of effects before making
control hierarchies one of their central examples.

------
athenot
This applies to programming too. To remove a piece of code (or even to improve
it), one must first understand what it does.

~~~
swagasaurus-rex
What it does: Makes my life harder. This is a second order effect.

------
qubex
There seems to be a bit of confusion regarding what “second order thinking” is
(awareness or consideration of the consequences of consequences) and an
instance of it (removing a fence without understanding why it had been erected
in the first place). The latter is an instance of the former (or rather,
absence thereof) but the former has far greater ramifications and applications
than those that are (currently) being discussed in these comments, which seem
to be concentrating either on software engineering aspects (abstractions, to
name one) or on the idea of banishing hierarchy from firms. That’s all fine
and well, but it hardly begins to scratch the surface of what the author
presumably thought this principle encompasses (and with whom I agree).

Anybody interested in second-order-thinking and decision-making could do far
worse than obtain a copy of Dietrich Dorner’s excellent _The Logic of Failure:
Recognizing and Avoiding Error in Complex Situations_ (1997) wherein the
author explores “patterns of thought that, while appropriate in an older,
simpler world, prove disastrous for the complex world we live in now”. One
important aspect of those errant heuristics is the failure to consider
consequences of consequences. I highly recommend it.

~~~
khafra
> what “second order thinking” is (awareness or consideration of the
> consequences of consequences)

This is a valid interpretation of the term. Another, more specific
interpretation is "including other minds in your mental model," e.g., when
you're imagining the results of your actions, you don't just include actions
and reactions of a mechanical nature. You also consider other agents, their
values, and their resources.

------
api
This is usually put forward as a conservative parable. I'm not sure it
necessarily takes a position there. It does not assert that the fence should
not be removed, just that one should make the effort of attempting to
understand its context prior to doing so.

~~~
winstonewert
Indeed, I've always find it a little bizarre that anyone objects. Do they
really think the best strategy is not to find out why the fence is there
before removing it?

~~~
goto11
The issue is when nobody really knows...the fence have just been there as long
as anybody remember. Then people start to make up justification. Maybe the
fence protect against trolls? Maybe the fence is important for the moral
character of the population, and if it is removed people will think there are
no limits to anything and will soon descend into murder and cannibalism.
Better safe than sorry!

~~~
winstonewert
Is that an objection against the story's point?

The fact that people might come up with silly/nonsensical/bad justifications
for the fence doesn't seem undermine the importance of doing due diligence to
determine if there is a good reason for the fence in the first place.

~~~
goto11
Due diligence is great, but it is an objection against the default stance of
keeping the fence if you can't explain why it is there. The fence becomes
onions in the varnish or cargo cult. At least in software development it is
poison to have too many "we cant change that area of the code, nobody
understand what it does". Sometimes you just have to tear down the fence and
observe the consequences.

~~~
winstonewert
I guess I don't read the parable as insisting that we have to keep the fence
if we can't find the reason for it after due diligence. It simply doesn't try
to speak to that case.

~~~
goto11
It is stated quite explicitly in the article: "Do not remove a fence until you
know why it was put up in the first place."

It follows that you can't remove a fence if you cant figure out why it was
created in the first place.

~~~
winstonewert
What are you, some kind of robot? (If so, awesome!) This is natural language,
you can't treat it like a statement in predicate logic.

Its very common in natural language to state general principles which apply
most of the time without intending it to be an iron-clad rule that would apply
in any circumstances without exception.

For example, if there is a "Stay off the grass" sign, you'd avoid going on the
grass, but you'd still go on if the need was important enough.

The case of being unable to find the reason is an exceptional circumstance in
which the principle does not apply, at least in quite the same way.

------
fultonfaknem42
I can't help but thinking about the 5 monkeys and a ladder.

[https://www.wisdompills.com/the-famous-social-
experiment-5-m...](https://www.wisdompills.com/the-famous-social-
experiment-5-monkeys-a-ladder/)

(Even if it is bullshit)

------
warbaker
I hate Chesterton's Fence.

We keep knocking down fences and it keeps being great, the most recent being
the millenia-long prohibition on gay marriage.

People put up fences for all sorts of dumb reasons. If you see a fence that
seems to cause more harm than good, knock it down. In the rare situation where
this leads to surprising problems, put the fence back up.

In software, most WTFs are just bad engineering. You should figure out what
the code does and how you can do it better, not take a step back and
contemplate the mind of its author.

~~~
nebulous1
> In software, most WTFs are just bad engineering. You should figure out what
> the code does and how you can do it better

This is exactly what Chesterton's Fence suggests

~~~
warbaker
No, Chesterton's Fence says for you to leave and think about why someone put
it up originally, and figure out what was good about the fence. What you
should instead do is look at the fence and the dangers on the other side and
see if it seems worth it.

A lot of 'fences' in engineering are there for no good reason at all, so
blocking until you can come up with some good reason for the fence is a waste
of time.

Chesterton would have you believe that the ancients had great wisdom, and that
you should try to find that wisdom before you make changes to anything. The
reality is, the ancients knew even less than you do, reasoned worse about
problems, and used inferior systems for generating solutions. Progress! It's
real!

To remind what Chesterton said: "The more modern type of reformer goes gaily
up to it and says, "I don't see the use of this; let us clear it away." To
which the more intelligent type of reformer will do well to answer: "If you
don't see the use of it, I certainly won't let you clear it away. Go away and
think. Then, when you can come back and tell me that you do see the use of it,
I may allow you to destroy it."

~~~
nebulous1
> No, Chesterton's Fence says for you to leave and think about why someone put
> it up originally, and figure out what was good about the fence

I don't see as much difference between that and "figure out what the code
does" as you do. I agree they have some differences, but ultimately a code's
functionality and the reasons why its functionality exists in its current
location are strongly related. The "go away first" part is a parable, I don't
think you have to actually go away.

Overall I'm somewhere between you and the article's author. I think your
ignorant ancients argument has some merit, but only in certain cases. For
instance, I don't see why the author is assuming people who promote flat
hierarchy companies never actually considered what the function of the
hierarchy was. This seems pretty ironic given that his whole point is not to
assume that builders haven't engaged their brains. Also, as with ignorant
ancients, it's possible that these hierarchies evolved, which could mean
they're functional but not optimal, and may in fact no longer be required.

On the technical side, I think we've all sat down to rewrite some code that
looks too complex, only to have the reasons for the complexity become apparent
as we research the subject. This might just be a case for better
documentation.

------
verganileonardo
After I learned the concept of First order thinking, I have noticed how most
mediocre managers incur in problems of it.

They save money on saving, without realizing it is going to make every waste
more time. They make a decision that only makes sense if no competitors react.
They solve problems that end up causing others. It is impressive how this
simple ability is a great predictor of performance.

------
enaaem
One interesting book I have read is Prisoners of Geography, and it really made
me think differently on geopolitics. Natural resources, trade routes and
defensive barriers have a huge impact on a countries geopolitical strategy.

It made me go from “Why the hell are they doing that!?” to “reality is
probably more complex”.

------
jxramos
is the notion of second order thinking a formal term in philosophy or logic or
something? [https://fs.blog/2016/04/second-order-
thinking/](https://fs.blog/2016/04/second-order-thinking/)

~~~
ChuckMcM
I have always associated second order thinking as part of the role of a
systems analyst. Systems analysis is a discipline that deals in systems and
their response to changes in input or environment. The notion of second order
effects are essentially the recursion of the system outputs perturbing its own
inputs leading to "second order" outputs.

I have always read Chesterton's Fence is an allegory for making one self aware
of these effects prior to changing a system.

~~~
jbay808
I always thought of it in the sense of a Taylor expansion.

First-order thinking suggests that every system reacts linearly according to
whatever the dominant factor is (the way you would basically expect). For
example, increase prices and your sales will decrease.

Second order thinking suggests including the next-more-complicated effect in
your model; effects that are negligible for small perturbations have to be
taken into account. Increase prices and your product gets perceived as more
exclusive and higher quality, and despite the valid decrease that the first-
order effect predicts, sales go up.

~~~
ChuckMcM
I agree, that is a perfectly valid example. You've perturbed the system
(raised prices) and there is the "expected" input and the "input that arises
from the perturbation."

------
danschumann
As suicide and depression are on the rise, I think we've removed many fences
without even knowing it. Social customs replaced by technology. Lessons not
passed on but ill-got through tv. Assuming we know better than all of the
customs of human history. Jamming everyone, whether round or square, into the
same hexogonal hole.

Proverbs 22:28 "Do not move an ancient boundary stone which your fathers have
set."

~~~
brain5ide
That's a valid concern. Although, I'm more inclined to think that it's rather
linked to our leveling up in the Maslow hierarchy. Caring for next meal is
replaced by caring for some other concerns that are less controllable.

Also, regarding the social customs, the point is that groups of people are an
organism that has to adapt to the environment and that environment has
changed. Social customs hold a small town together, but it's absolutely
unreasonable to depend on them in a city, where you're living next to
strangers that change all the time.

~~~
danschumann
Why live in a place where you don't know your neighbors, then? Isn't that
depressing in and of itself? In an ideal world, your friends would become your
neighbors and people would move closer to the people they love, to make "love
your neighbor" easier.

~~~
brain5ide
Scarcity and anisotropic distribution of resources? Dynamism of your lifetime
requirements? Also, some age old sentiment that is encoded in the "keep your
friends close and your enemies closer" adage? That would be my 3 guesses for
most signifigant contributors.

~~~
danschumann
Also, I would think scarcity, in this climate of supply chain interruption,
would favor the spread out places.. where my supply chain is in my back yard,
if I'm a farmer, whereas the city needs to funnel much into a greedy-little
area. And when you say "resources", again, you must not be talking about love,
which is what most people truly want, when they earn their money. My earlier
sentiment of wanting to live near friends, this makes the "love" resource much
more plentiful. Perhaps city folks just don't understand it.

