Hate crimes, hate speech, hate groups… It is quite possible that we have less of these things today than ever before – they originated before our age, as anybody who’s read Chaucer’s Prioress’s Tale can vouch – but we have never obsessed about them quite so much. What is hate in its 21st century, British sense? And why are some varieties of hate seemingly justified and good, and some appalling?

In the public sphere, hate often seems ludicrously hyperbolic.