Sometimes a concept is so good one must ruthlessly crib from another source – So here ya be, the notion of Chesterson’s Fence and how important it is to understand the reasons why something was done in the first place.

“Second-order thinking will get you extraordinary results, and so will learning to recognize when other people are using second-order thinking. To understand exactly why this is the case, let’s consider Chesterton’s Fence, described by G. K. Chesterton himself as follows:

There exists in such a case a certain institution or law; let us say, for the sake of simplicity, a fence or gate erected across a road. 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.”

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Chesterton’s Fence is a heuristic inspired by a quote from the writer and polymath G. K. Chesterton’s 1929 book, The Thing. It’s best known as being one of John F. Kennedy’s favored sayings, as well as a principle Wikipedia encourages its editors to follow. In the book, Chesterton describes the classic case of the reformer who notices something, such as a fence, and fails to see the reason for its existence. However, before they decide to remove it, they must figure out why it exists in the first place. If they do not do this, they are likely to do more harm than good with its removal. In its most concise version, Chesterton’s Fence states the following:

Do not remove a fence until you know why it was put up in the first place.

Chesterton went on to explain why this principle holds true, writing that fences don’t grow out of the ground, nor do people build them in their sleep or during a fit of madness. He explained that fences are built by people who carefully planned them out and “had some reason for thinking [the fence] would be a good thing for somebody.” Until we establish that reason, we have no business taking an ax to it. The reason might not be a good or relevant one; we just need to be aware of what the reason is. Otherwise, we may end up with unintended consequences: second- and third-order effects we don’t want, spreading like ripples on a pond and causing damage for years.”