As a rule I try to steer clear of criticising young people just for being young. Every generation deserves the chance to make mistakes, regret them, and bring about progress in their own way. But there is one area where the millennials are retrogressing so shockingly hard and fast that I feel I have no choice but to rail against the folly of youth. I’m talking, of course, about freedom of speech.

As the weekend’s latest “no-platforming” incident shows, all too many young folk would happily snuff out free speech in the name of being "offended". And this is something we should all be worried about.

For those of you who don’t know, “no-platforming” is when one person or group refuses to give another person or group it doesn’t agree with an opportunity to debate, or refuses to share a stage with them. A couple of days ago veteran gay rights campaigner Peter Tatchell found himself no-platformed by the National Union of Students. The reason? This is where it all gets ridiculous. Mr Tatchell, it seems, had dared to sign a letter last year supporting criticism of the increasing use of no-platforming by students groups and universities. He had, in other words, supported free speech.

This all came about after feminist students at Cardiff University tried to prevent fellow feminist Germaine Greer speaking at their institution because she had previously said she did not believe that post-surgery transsexuals were automatically women. The students accused Ms Greer of hate speech and misogyny against transsexuals, and said allowing her a platform to speak – even on an unrelated issue - meant endorsing her view on transsexuals. And now the NUS accuses Mr Tatchell of guilt by association, despite the fact that he defended not Ms Greer’s view on transsexuals, but her right to express it. The irony that Tatchell and Greer have spent their entire lives campaigning for the equality these youngsters claim to be protecting seems hilariously lost on them.

But this is only the latest in a slew of such debacles; hardly a week goes by without some university campus or student group trying to shut somebody up. It’s all so absurd. The wish to silence someone, even someone you don’t agree with, even someone risible, is immature and futile. It’s also morally wrong. In a democracy we must allow people to hear every argument, to make their own choices.

And surely university campuses, where young minds are bended, moulded and stretched, are the very places in society where pretty much every view, no matter how extreme, should be given a platform. Does that include racists, bigots, misogynists, jihadists and Holocaust deniers? Well, yes, as long as the opposing view is strongly represented. Young people should relish the opportunity to argue the right point, to fight the good fight.

I thought we’d grasped this particular nettle back in 2009 when writer and historian Bonnie Greer, an African American who has lived in the UK for many years, calmly, elegantly dismantled then-BNP leader Nick Griffin and his odious racism in front of millions on Question Time. Following much debate over whether it was right to allow Mr Griffin a mainstream platform, Ms Greer showed that argument and debate are the best and only ways to bring down bigots. In the following years, Mr Griffin and his former party were roundly rejected by the vast majority.

With this in mind, why are today’s young people so prepared to close down debate? What happened between 2009 and now? Two words: social media. While platforms like Twitter and Facebook provide a fantastic opportunity to debate, in too many cases they have transformed into echo chambers where people only hear and repeat views they already agree with. Then, when they switch on the TV or open a newspaper and don’t automatically see their own view or feelings reflected, they get upset and frustrated. This only leads to further polarisation – if you’re not with me, you’re against me; your views are “offensive”.

I genuinely worry that such isolated positioning of our online personas will eventually kill off our ability to think critically and work through complex questions.

No one has the right not to be offended. That is the sometimes difficult concept that accompanies true free speech. It’s a hard lesson to learn. But it’s one that the digital generation needs to compute, and fast. If not, we risk losing the very freedom of expression we’ve spent generations fighting for. And that would be the biggest mistake our young people could ever make.