The 1992 movie A Few Good Men gave us the memorable phrase "You can't handle the truth!", beloved by internet memesters. Yet it is just so: we cannot handle the truth, and indeed we would far rather have certainty than know the truth uncertainly. Certainty brings with it a contentment that we long for, even while we profess that our longing is for the truth. We want to know, we say... but what we desire is the certainty we call 'knowledge', or 'science', which we then falsely conflate with truth. We are not committed to the truth at all. We are desperately seeking certainty - and will sacrifice anything - even and especially the truth - to get at it.
Here is a paradox: certainty (a mental state) seems to rest upon alignment with the truth. We think that if we know the truth, then we are certain. Therein lies precisely the pitfall - we feel certain, and this feeling has nothing at all to do with whether what we are feeling certain about is true. Yet beyond doubt, the only thing our feelings can offer certainty upon is how we feel - and even then, we can be deceived. We can persuade ourselves that we hate someone we love, or vice versa. As Wittgenstein realised, our mental state of conviction is in no way dependent upon any associated truth.
In the grab-bag of half-developed ideas that is contemporary psychology, it is accepted that we are uncomfortable with uncertainty. One experiment conducted in 2016, based upon the ever-popular delivery of electric shocks, suggested people would rather be given a shock immediately than suffer one at an indeterminate point in the future. The amygdala, which mediates fear and anxiety, can be activated by incomplete information - consider a simple example of having said something that you worry might have caused offence. Not knowing is, in itself, a significant cause of anxiety. Certainty alleviates fear.
It is therefore not surprising that we have made an idol out of this thing we call 'Science', which no longer means (as it once did) 'knowledge'. Two centuries ago, many and varied were the things that could be called a science. Today, this term denotes the exclusive authority of those experts upon whose say-so we attain certainty. Yet the history of the sciences is not just theories being replaced with later theories that explain situations with greater accuracy. It is also the history of plausible-sounding gobbledegook that was accepted as knowledge by humans who placed more value on certainty than on truth.
The psychological description of this kind of certainty is nothing of the kind: it is literally faith. Never mind the mismatch between belief and certainty we ascribe to the religious - this has little to do with religion and everything to do with human nature. Our desire for certainty is such that we will take claims on faith as long as in so doing we can feel certain. The truth, on the other hand, is always uncertain. It is only in logic and mathematics that a system admits of truth by 'proofs', which is to say, reliable inferences from foundations that are secured by definition. Once we depart from the artifice of constructed systems, truth lies distant from us and requires tremendous effort to uncover - and even when it is uncovered, it is still uncertain.
And here we are today, still just as human as we ever were. We hide from the truth because it is too challenging - too exhausting! - to seek it, and also because that very search is neither guaranteed nor likely to end in certainty. Instead, we choose certainty, by whatever means it is offered to us. A hypothesis dressed up in theoretical clothing. A non-binding referendum that becomes binding. A fallacious argument from authority. Any escape at all to avoid dealing with the inevitable uncertainty of the truth.
This is the paradox of conviction: we are certain that certainty is truth, and that only the truth deserves our certainty. Thus, we fail to accept that uncovering the path towards truth requires a commitment to uncertainty. The most essential skill for any scientist to cultivate is the one we don't want from them: an openness to the inevitable uncertainties of scientific practice. Certainty and truth are not one and the same, but the exact opposite of one another. Knowing this, we still gladly choose certainty over truth, without hesitation. We must know, and we must know with certainty... and so the truth is forever barred to us.
The opening image is Conviction by Dan Sisken, which I found at his art blog. As ever, no copyright infringement is intended and I will take the image down if asked.