The question every certainty must survive

Picture two people who both claim to know the truth. One says: "My theory explains everything, every event fits into it." The other says: "My theory predicts this, and if that happens, I'm wrong." Which of the two would you trust? Our intuition often picks the first, what explains everything sounds powerful. The philosopher of science Karl Popper showed it is exactly the other way around. The second is doing knowledge. The first is selling an illusion.

Popper's insight is called falsifiability, and it may well be the most useful thinking tool the twentieth century produced. A claim only becomes scientific, only worth taking seriously as knowledge, when it can in principle be refuted. Not: has it been proven? But: what would knock it down, and have we tried? A theory that is compatible with every outcome, that has an explanation for everything, in reality tells you nothing, because it rules nothing out.

The trick of the closed system

Notice how a certain kind of story works, a conspiracy theory, an ideology, an investment promise that is too good, the patter of a guru. The shared trait is that they are immune to refutation. Evidence against the theory? That is precisely proof of how deep the conspiracy runs. The prediction did not come true? The time was not yet ripe. You have doubts? Then you have not gone far enough. Every objection is swallowed and turned into fresh evidence. That is not strength. It is the structure of a trap. An idea that cannot lose has nothing to win.

The healthy attitude does the opposite. It says in advance: this is what I expect, and if it turns out otherwise, I was off the mark. A good entrepreneur states what he thinks will work, and builds in such a way that he can discover cheaply when it doesn't. An honest thinker names what would make him change his mind. Anyone who cannot answer that last point, who has no answer to the question "what would prove you wrong?", believes, however clever it sounds, and does not know.

The question, daily

Make it a habit, with every firm claim that comes at you and with every conviction you hold yourself: what could disprove this, and has anyone tried? With a sales pitch, a news report, a piece of advice, an assumption of your own. It is not cynicism. It is the opposite. The cynic believes nothing; the Popperian believes provisionally, but keeps the door to refutation open. That is exactly how knowledge grows: not by being proven right, but by being able to turn out wrong and surviving it.

A thought to take with you: take one conviction you are certain of, about your work, your market, yourself. Ask: what would I have to see in order to conclude that I am wrong? If you can think of nothing, that is no sign that you are right. It is a sign that you have never tested it.