Hopper's observation on delusion calls to mind a recent BBC Radio Four series on a background point about the rise of the Qanon fantasy.
The BBC's correspondent, Gabriel Gatehouse, had been in Washington to report on Joe Biden's inauguration as President, so of course also witnessed the invasion of the Capitol building. Among the invaders was a man in fancy dress, calling himself the "Q Shaman" , and carrying a "Q Sent Me" slogan. Gatehouse managed to meet this character, and this started his quest to investigate the origins of what has become a sort of cult.
He was unable to trace its originator, though found its route from obscurity to Facebook; but he made a significant point that its spread paralleled the 16C Malleus Maleficarum.
Malleus Maleficarum was a book by a German priest, expounding his ideas of evil witches being everywhere, and it sparked some 2 or 3 centuries of brutal "witch-hunting" across Europe.
The parallel, apart from that of eerily similar dogma, was the rapid and recent advances in communications. The book exploited the recent development of printing and publishing. Conspiracy-theories like Qanon exploit similarly, the Internet.
The crowd psychology among the ideologies' respective followers is the same; so is ideology using the rapid rise of new ways to disseminate its ideas widely. The main difference is only how it's done.
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It's worth reading Charles Mackay's Extraordinary Popular Delusions and the Madness of Crowds, first published in 1841. Though rather heavy-going prose by our standards, it covers the histories of witch-hunts, the "South Sea Bubble", alchemy, assorted crime themes, and several other mass-delusions.
Interestingly, the chapter on "The Alchymists" reveals many doubted it even then – including some alchemists themselves disillusioned by its constant failures. One had even reported a symposium of the art being full of lame "if only" excuses such as: "~ I had heated it for another hour" , or " ~ my retort had not broken" . One nobleman imprisoned both "alchymist" and laboratory, promising him freedom only once he'd actually made the gold!
I would recommend the book as required reading for all politicians and conspiracy-fantasies.
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I don't know Hopper's angle on Covid and this is not a political, nor medical, forum anyway; but what worries me about the climate-change debate is the appallingly low level of basic scientific and engineering knowledge, even at lay level, displayed publicly by most politicians, journalists and campaigners. Knowledge taught in school geography and science lessons. Or at least, used to be taught.
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When it comes to mass stupidity in the face of logic, there is nowt new!