Doubt is a thinking tool that has unfortunately morphed into an emotion: fear. Everyday language uses the word doubt with all sorts of negative connotations that are unwarranted. People see doubt as indecision, dithering, confusion, hesitation, etc. Those tend to then collectively accelerate towards fear. Thus missing out on a truly marvellous tool, because fear trumps thinking.

The clarity of doubt reads like an oxymoron, and a phrase which only a moron might utter. But it is, in fact, a memorable way of stopping oneself from missing out on the benefits of such a brilliant thinking tool. The key insight is that of negation: reason by subtracting, not by adding. Doubt forms the basis of the modern scientific method by elevating the concept of falsification, which holds that one can only disprove a hypothesis but never prove it outright. It’s only possible to be certain about being wrong, never about being right. Therein lies the clarity, whereby one can know what is false with certainty, and act accordingly.

Doubt is the instigator of Bayesian reasoning under uncertainty. A belief that has yet to be proven wrong gains favour over time until it is decisively proven wrong. If that time never comes then that belief simply has a high credence, as opposed to having 100% certainty. In fact, doubt also makes it intuitive that a belief that has been proven wrong can still function well as an approximation. This is indeed what happens in physics, e.g., Newton was proven wrong but his theory remains an excellent approximation.

Cognitive psychology has shed light on the fact that people resolve dissonance in their heads by affirmation, i.e., doubling down on one belief and completely denying the alternative. This is also known as the confirmation bias, with which everyone is born. The scientific method guards against this explicitly. So the rigorous way to resolve a cognitive dissonance is to reason by negation. That is, first discard both beliefs that are creating the dichotomy. Then take the Bayesian approach to build up evidence in favour of one or the other belief, and never ignore counter-evidence to the favoured belief.

Doubt never stops one from acting with conviction. Instead, it forces one to ensure that a strongly held belief is not provably wrong. That doesn’t mean the belief is automatically right, because beliefs lie on a spectrum from wrong to right, with the only certainty residing on the wrong end. Therefore, the salient question to ponder always is Am I wrong? This is all too often mistaken for being sheepish, or lacking in confidence, etc. But enlightenment and wisdom are the friends of only those who dare to doubt. That requires courage, and humility. Never fear.