Wife and I have had several versions of a conversation about how little we would have to say if we restrained ourselves to speaking only about what we know with high confidence (“facts”).
Obviously we would have to say almost nothing, about anything, ever.
So what’s happening when we do talk? We speculate a lot, of course.
Speculation isn’t something that humans occasionally do when we have the chance, like swimming in the ocean: it dominates most of our conversations. We are alway speculating. There are many gaps in every line of reasoning, all filled with hunches and guesses, sometimes big glaring ones. It’s just how we all work, and it’s a feature and a bug. It only becomes a concern when people start doubling down on their ideas when the stakes are higher.
But that does happen. In fact, that also happens constantly.
People often use their intelligence for all kinds of nonsense. Slick motivated reasoning spreads just as much bullshit as ignorance, and maybe much more. Specialists step out of their wheelhouses and authoritatively make foolish statements on other topics. This is so common that it has become a PR problem for expertise — experts keep making expertise look bad, mainly by not just sticking to what they actually know.