We are seeing “the nihilistic rejection of the concept of expertise” on the grounds that everything is now a matter of opinion. We see the BBC giving equal time to cosmologists and flat-earthers, supposedly on the grounds of “balance”. Mark Thompson argues this in a recent book Enough Said. We are living in a “post-fact” world. How then do we get well-informed choices made about policy options? As the  Guardian Weekly says: “The Chinese politburo, campus censors who close down debate in the name of political correctness, and Twitter flash mobs have more in common than they know…they all seek to gag anyone who doesn’t share their world-view” [see  Guardian Weekly, 23.9.16, p.35].