Imagine you are a newly appointed town mayor in the 1920s. You’re keen to bring change to the community and make a positive impact. You pull up your suspenders, pick out your favourite hat, and take to the streets. Soon you find a fence, built across a path that you know is popular amongst the townsfolk.

A quick-thinking mayor might see the fence and say, “I don’t see the use of this. Let’s tear it down so that it no longer gets in people’s way”. To which a more reasoned and forward-thinking mayor might say, “I don’t see the use of this. However, just because I don’t see the use of this, doesn’t mean the fence has no use to somebody. I can’t reasonably destroy this fence without knowing the reasons why it was built.”

I stumbled across the work of GK Chesterton from his 1929 book The Thing. It contains the principle commonly known as Chesterton’s Fence, something that is within the Wikipedia editing community even today.

The logic states that until we establish the reason why something was created in the first place, we have no business destroying it. The reason may be no longer relevant, or even valuable; we just need to be aware of what the reason is. And this applies whether we’re debating to keep a fence, a sentence on Wikipedia, or a big decision that needs to be made.

When we’re making big decisions, we ought to be aware that some choices can have long lasting effects. Like where to send your child to school, whether to take that new job, who you really want in your circle of close friends, or how to react to that comment from your mother-in-law.

It goes without saying that in situations like these that we should take on more active and reflective thinking processes before hastily making decisions. Second-order thinking is the practice of not just considering the consequences of our decisions, but also the consequences of those consequences – just like an expert chess player might be thinking many moves ahead when deciding which piece to move next.

Everyone can manage first-order thinking, which is just considering the immediate anticipated result of an action. It’s simple and quick, usually requiring little effort. By comparison, second-order thinking is more complex and time-consuming. The fact that it is difficult and unusual is what makes the ability to do it such a powerful advantage.

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. Like Chesterton’s Fence, we ought to establish the reason behind decision-making – and the future effects of our decisions – before we act.