“In other words, as soon as you move beyond hard data and facts that can be rigorously verified, you are entering into a realm where you, and like-minded people around you, can talk yourselves into believing almost anything you like to believe. And precisely because you’ve arrived at those conclusions by spelling out what seems like a rational argument, and because you’re surrounded by trustworthy-seeming people nodding their heads and signalling agreement, you feel confident that you’ve fixed beliefs solid enough to act on. It’s a human failing that Peirce identified as long ago as the 1870s, but I think that social media amplifies it.”