Some time in the early 1960s when my father was driving taxis in Manchester, he had that April Ashley in the back of his cab. For readers who don’t remember April Ashley, let me quote from her website. “My story begins in 1935 in a tough, working-class area of Liverpool where I was born as a boy... In Paris, I debated with myself the decision to have a sex change... I knew I was woman and that I could not live in a male body. I had no choice. I flew to Casablanca and the rest, as they say, is history.”

It must have been a short time after her operation in Casablanca that my father ferried her around in his taxi for a day. He liked her, found the story of her ordeal fascinating and moving – “An education,” he called it – and wouldn’t tolerate any sarcasm, weird as the idea of a sex change then was. To this day he stands guard in my imagination over any inclination I might have to judge ungenerously.

So in the matter of transgender politics I can be trusted to show respect. If Germaine Greer has upset people who might have looked to her for understanding, they have my sympathy. But since she hasn’t called for their operations to be reversed, or for them to be physically harmed, not a single voice should be raised against her delivering a lecture on any subject she chooses at a British university.

Our country is in a censorious mood. The more educated we are, the less we are prepared to tolerate views contrary to our own. Shake any institution of higher learning and a dozen boycotters will fall out of it. If the academic community gets its way, we will soon all be speaking with a single voice.

But it isn’t just the desire to silence dissenting opinion that should worry us. Let us say that Greer didn’t just happen to think differently from those she has distressed but intended, for whatever reason – because she’s Australian, say – to go out of her way to needle them. Why, even then, should she be denied the right to a platform?

It isn’t only in the name of free speech that the views of an itchy polemicist should be tolerated – and I say itchy polemicist promoting thought, not itchy ideologue promoting violence – but because provocation is indispensable to the workings of a sound, creative culture. The loser, when silencers have their way, is not the provocateur but the provoked. To be easily offended is to be shut off from the invigoration of that argumentative give-and-take we call liberty; not to understand the poetics of provocation is to miss out on the joys of living in a literate and robust society that excels at satire and burlesque.

We hear too much of “phobia”. Attach “phobia” to any cause you care for and you have ring-fenced it against the words of the critic and the devious antics of the clown alike. Nothing is to be mocked; everything – except the act of critical dissent itself – is sacrosanct. Thus have we created for ourselves an impoverished world of touchy fools who understand no mode of address other than the internet’s yes/no, like/dislike, thumbs up/thumbs down discourse of the dumb.

Take some of the responses to Martin Amis’s splenetic and self-consciously snobby dismantling of Jeremy Corbyn in The Sunday Times last week. That the straight-faced of social media were going to throw a blue fit over this would assuredly have entered Amis’s calculations. It can be fun for a writer with a comic gift to drive the over-principled into an apoplexy. That’s part of what a comic gift is for. “Dance,” says Martin Amis, and true to expectation, they dance their hobbled dance, outraged by his ridicule, sickened by the position of educational privilege from which he mocks Corbyn’s intellectual penury, primly unamused by the unashamedly ad hominem nature of his attack. (No matter that with Jeremy Corbyn – a man admired for nothing more substantial than “authenticity” – ad hominem is all there is.)

It is a strange, cabbalistic world out there in the celibate darkness of digital resentment forums, where people for good reason denied a platform of their own cling to the coat-tails of those published in the daylight, froth in envious rage, share one another’s small and bitter diatribes and as a matter of principle find nothing funny, not even when it patently is – as for example, Amis’s really rather fond description of “weedy, nervy, thrifty” Corbynites each “with a little folded purse full of humid coins”. It’s that word “humid” that does the trick and marks the writer his detractors will never be.

A bad habit has evolved, below stairs, of calling any writer with whom you disagree about anything a twat, and his or her books bollocks. As a tactic, this is poor. It weakens your argument if you can only admire art made in the image of your own predilections, and shows you have neither eye nor ear for art at all.

As for snobbish derision, it is of noble ancestry, going back to Hamlet twitting Polonius, Pope, Swift, Wilde, Waugh: a line of scurrilous mirth whose slithering ambiguities make a Charlie of whoever can’t keep up. Equivocation is at the heart of literary insult, harnessing seriousness to comedy, earnestness to lightness, teasing the single-minded into taking offence. Sadistic? Yes, but then again no.

The impulse to irresponsible play is lost on the easily provoked who think a writer must mean what he appears to mean, say what he seems to say, or indeed say anything, because saying, reader, is the least of what a writer does.