Design Thinking and Chesterton’s Fence

18th September 2023
4 min read

This article I originally posted on the Virtimachi website almost two years ago. I've edited and reposted it here to serve as both a reminder and a reference. I had wished in my last post that I could have linked to this one. So here it is:

I come across an interesting collection of wisdoms by Merlin Mann the other day. Appropriately called The Wisdom Project. It’s a remarkably practical list of wisdoms picked up through life experience, worth a read. One particular pearl, however, triggered my curiosity:

Learn about Chesterton's Fence. Then avoid changing a given situation before you understand some of the reasons why it's remained unchanged for so long. (Thanks, G. K. C.)

I had no idea what Chesterton’s Fence was. Chesterton’s Fence is quoted from G. K. Chesterton’s 1929 book, The Thing. It goes:

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."

Put simply; before you pull the fence down, understand why it was put up.

Farnam Street has an excellent deep dive into Chesterton's Fence, unpacking how it relates to second order thinking. In brief, what second order thinking means is not just considering the consequence of your action, but considering the consequence of the consequence of your action. The fence may appear to only serve to define a boundary, until the foxes eat your neighbour’s chickens. The first order is to define the boundary, the second order is to protect the chickens. Seeing the immediate consequence is simple, understanding the cascade of consequences takes much more consideration. In this light, Chesterton’s Fence was in many ways part of design thinking long before we had design thinking. Specifically, the first and most important part of design thinking. Empathy.

Design thinking is a fairly modern and reasonably formal framework for solving problems. The process has been used throughout many industries for decades, but giving it structure has allowed it be almost universally (and successfully) adopted for many diverse applications. Not just design. The application of design thinking is an entire article in itself. The summary is really:

  • Empathise - understand the problem and the users
  • Define - clearly define the problem
  • Ideate - ideas time!
  • Prototype - create testable solutions
  • Test - learn, then go back and repeat
Design Thinking Process

Empathy is, by far, the most critical of these steps, especially in medical devices. If we cannot empathise with our users, the foundation for every other stage of development is flawed. Ignorance is bliss, but it can kill a project, or worse. This is Chesterton's Fence: apply several orders of thinking to the problem to gain empathy.

There are plenty of good tools to help us empathise with users. For example, the Problem Tree Analysis. In this framework, the trunk represents the problem (fence), the roots are the causes, and the branches the effects. We need to ask “why” at every level down to help reveal root causes, biases and assumptions. A full understanding of what we see as the problem could very well prove to have been a reasonable solution for a deeper problem.

Problem Tree Analysis

That’s not to say things can’t be improved. But don't just change things for the sake of changing them. First you must understand why things are the way they are. By practicing the design thinking process, and using second order thinking understanding what causes (and the causes of those causes) the current fence to exist, you will know if it is wise to remove it or not. Ultimately so that you may know how to change it for the better.

So, if you ask a good designer if they know about Chesterton’s Fence, they’ll likely have no idea what you’re talking about. But they’ll practice good second order thinking anyway.

As always, I'd love to hear your thoughts. Get in touch via LinkedIn, or email.

ⓒ Lincoln Black 2024

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