The students I know seem in many respects far superior to my own generation of pot-smoking layabouts. They work harder, think harder, agonise more over big ideas. And if they sometimes come to the wrong conclusions, so what?

"Youth is easily deceived because it is quick to hope," said Aristotle. Every generation of young idealists makes mistakes. It's the reaction of the grown-ups that worries me.

There are some things you mustn't even think. 

The grown-ups in charge of Cambridge University, for example, have just withdrawn a fundraising video featuring the historian David Starkey, after hundreds of students and lecturers signed a letter accusing him of racism and sexism. The letter provided close textual analysis of various "deeply offensive" remarks made by Starkey, including his claim, after riots in 2011, that Britain's white working classes "have become black; a particular sort of violent, destructive, nihilistic gangster culture has become the fashion".

Let's be honest – Starkey loves annoying people. He got all of middle England in a rage this year by declaring that the Queen had "done and said nothing that anyone will remember".

He's a professional, sometimes tiresome, controversialist: "the rudest man in Britain". He is also a brilliant academic, a popular TV historian and – as the gay, club-footed son of a Cumbrian cleaning lady – a one-man study in social mobility.

But being gay, disabled and working-class is no longer enough to appease the gods of intersectional correctness. Neither is being a Nobel prize winner, as biologist Tim Hunt discovered after he made a cack-handed joke about female scientists.

This atmosphere of intellectual intolerance has rolled over the United States and Britain like a sea mist. Trigger warnings, safe spaces, no-platforming: all of a sudden, students everywhere are campaigning for the right not to learn.

Unfashionable or discomfiting ideas are regarded as bio-hazards, to be removed from the campus with tongs. The emotional welfare of individual students trumps everything, including free speech (now dismissively nicknamed Freeze Peach).

When a child throws a tantrum, or runs around with his fingers in his ears shouting "Rhubarb! Rhubarb!" because he doesn't like what he's hearing, sensible parents pay no attention.

The same should be true of teachers, academics, editors – everyone whose job it is to promote the free exchange of ideas.

Alas, there will always be grown-ups who cannot resist getting down with the kidz. Malachi McIntosh, head of English at King's College, Cambridge, led the anti-Starkey campaign. He said this week that, having excised Starkey from its fundraising video, the university must now apologise for having put him there in the first place. "Simply blotting out history is, I think, and I hope you do too, not enough."

It would be hilarious if it wasn't so awful: a lecturer at one of the most exalted universities in the world, a man who must surely be familiar with the works of Orwell, insisting that "blotting out history isn't enough".

What else would he like to blot out? All pesky contrarians? Or just their pesky ideas?