The other day I was reading a book on the mathematics of uncertainty and how understanding it can lead to better predictions, when I quite unexpectedly came across this statement on page 171:

If we let it, Bayes can be a powerful tool for updating our preconceptions in the light of new data. What Bayes doesn’t do for us, however, is suggest how we should pick those prior beliefs in the first place. There will always be some people who hold their convictions with 100 per cent certainty – think of religious fundamentalists, anti-vaxxers or climate-change deniers.

Well, I say I came across it quite unexpectedly, but that is only because I was taken by surprise that it took the author until page 171 to lay into the climate sceptic and vaccine-concerned. Normally, academics who write on matters of uncertainty have rushed to such condemnation long before they have finished their preface. It seems they just can’t help themselves. If they need to illustrate how thinking about uncertainty can go horribly wrong, they invariably pick on the climate change ‘denier’ and the anti-vaxxer. They now go together like fish, chips and holocaust deniers, although on this occasion the author preferred instead to ram his point home by invoking the example of the religious fundamentalist. The choice of comparison matters not, however, as long as the reader understands that some people are just so irrational as to be downright unreachable. As the author puts it in the very next sentence:

What Bayes theorem tells us in these situations is that there is not a single piece of evidence, no matter how strong, that will ever shift these hardliners from their convictions.

Frankly, I don’t know where he got that particular nugget from, but certainly it wasn’t from the Reverend Bayes. There is absolutely nothing in the mathematics of Bayes’ Theory to suggest that there is a limit beyond which the strength of a prior belief can render the holder impervious to new information. That bit of prejudiced thinking comes straight from the author himself and is purely down to his prior beliefs about how climate sceptics and the vaccine-concerned came to hold their particular views. His understanding, for what it is worth, is based, as always, upon the assumption that the science is settled and that there can be no legitimate basis for ever holding out against a scientific consensus. The only possible explanation, in his mind, is that these individuals simply do not believe in updating their beliefs and have no time of day for evidence. How else could they have arrived at a position that is so remote, not only from his own, but from every one of his like-thinking academic chums?

It is obvious that the book’s author certainly knows all about the perils of the transposed conditional, but I would bet my shirt that he doesn’t appreciate that a prime example is the IPCC statement that scientists are 95% certain that over half of the recent warming has been anthropogenic. He seems to have grasped the important difference between aleatory and epistemic uncertainty, but I suspect he knows nothing regarding the extent to which that important distinction is ignored by the majority of climate scientists. He won’t be aware, I’m sure, of the profound flaws within the ONS data that were used by everyone who defends the effectiveness and safety of the Covid-19 vaccines, nor that the Office for Statistics Regulation, no less, has ruled the ONS data unsuitable for such analyses.  And though he will have been as aware as anyone of the impact of false positives when testing the asymptomatic, I wonder if he took that into account when he accepted the Government’s claim that there were legions of symptom-free Covid-19 disease-spreaders roaming the streets – the assumption upon which the multi-billion pound Operation Moonshot was premised.

In fact, I just don’t think he has the faintest idea of the extent to which evidence has informed the opinions of those he so confidently dismisses as being the equivalent of religious fundamentalists.

The reality is that there are many amongst those labelled as ‘anti-vaxxers’ and ‘climate-change deniers’ who are simply trying to abide by the philosophy of the empirical sceptic and, contrary to what the author might think, they have a very healthy regard for evidence. Should the author ever deign to interact with those individuals who he has unjustifiably accused of holding views with 100 per cent certainty, it would be nice to think that he would be prepared to apply Bayes’ Rule and modify his views of them in the light of the evidence thereby revealed. But I suspect that he would prove every bit as intransigent as those he condemns. I expect that there is not a single piece of evidence, no matter how strong, that will ever shift him from his conviction that ‘anti-vaxxers’ and ‘climate-change deniers’ are just mindless fundamentalists. Despite the fact that he himself offered no evidence to support his proposition that such people are intransigent and evidence-averse, he will continue to presume that he and his enlightened colleagues are alone in understanding the laws of uncertainty and hence able to remain open-minded.

Okay, rant over.

I can now return to reading what had, until page 171, been a reasonably entertaining and informative book. I shall take on board what page 171 has taught me about the author, and like a good Bayesian I will update my prior assumptions. None of this has been enough to put me off finishing the book, but it has only entrenched my firm belief that intelligence and academic status are not sufficient to prevent the individual from hypocritically falling into a silo of thinking, informed more by bigotry than by evidence or logic.