Here's one of my top Christmas wishes: let’s stop banning things we don’t like. I don’t know how it happened, but the clamour to ban everything and everyone we don’t agree with has got out of hand.

Donald Trump has deeply unsavoury and divisive views about Muslims. Ban him from entering the UK! Tyson Fury is sexist and a homophobe. Ban him from BBC Sports Personality of the Year! Germaine Greer, of all people, has some pretty unreconstructed views on transgender people. Ban her from speaking at a university campus!

Earlier this year, more than 130,000 people signed a petition to ban Kanye West from headlining Glastonbury in order to prevent “musical injustice”. That’s more people than you can fit in the field at the Pyramid Stage.

I have no strong feelings about Kanye West, but I share why many people found what the other three have said to be unpleasant, offensive or just wrong.

But there are always things in life which are unpleasant and offensive. Donald Trump is a dangerous loudmouth. Tyson Fury is a terrible role model. Germaine Greer is wrong on transgender rights.

Maybe it’s the instant, push-button, “something must be done” culture of the internet age. Adding your name to an online petition without a second’s thought is a gratifyingly rapid reflex to something that is irritating or outrageous in the news. It’s the digital equivalent of children stamping their feet in anger or frustration. My kids do it all the time.

But in the real world we can’t just wish away everything we don’t like. More importantly, banning stuff doesn’t mean it goes away — it just pops up somewhere else. Barring Trump from the UK is the political equivalent of playing Whack-a-Mole — he’ll just pop up somewhere else, twice as loud.

In a liberal society, offensive views should be challenged, not blocked. Bigots should be exposed and defeated in argument. Big-mouthed cretins should be ridiculed, not turned into martyrs (and certainly not elected president).

At the heart of this debate are some very serious questions: when does something offensive cross the line into something that incites violence or discriminatory behaviour? How should liberal societies deal with ideologies — such as Islamist extremism — that threaten our way of life?

In the coalition, there was a long-running disagreement between the Lib-Dems and the Conservatives over the answers to these questions. There are, of course, certain things that cross the line and need to be blocked, such as incitement to violence. But our view throughout was that you can’t simply ban ideas. Ideas take on a life of their own in people’s thoughts and fears. They can’t just be extinguished because someone in Whitehall says so.

While both parties took a hardline approach against violent extremists, we differed in our approach to non-violent extremists.

The Lib-Dems saw the solution in free speech where extremist ideas are beaten and discredited in public debate; the Conservatives sought to restrict or ban extremists from the airwaves or the internet for saying divisive things. The Home Office proposed so-called “banning orders” for groups that fell short of the existing threshold for proscription under the Terrorism Act — giving the Government far greater freedom to ban groups it didn’t like — and Asbo-style powers to prevent people from saying “extreme” things.

Towards the end of last year the Home Office produced a draft Extremism Strategy, which included everything from banning orders to “fundamental British values” tests for foreigners applying for visas, to powers to allow the Government to pre-approve TV programmes for broadcast.

More recently, thankfully, the Government appears to have backed off from some of the more unworkable ideas but still wants to go ahead with the banning orders and Asbo-style powers.

In the aftermath of the Charlie Hebdo murders in January, politicians of all parties rightly united to declare that a free society means having the freedom to cause offence. And that, surely, is the point: if an idea is offensive, it is the idea that must be defeated.

If we are to defeat Islamist extremism, we need to challenge and defeat the ideology. Bombing raids can help win military battles but they will not defeat the poisonous ideas themselves.

To do that, we need to take Islamic State on using technology, reason, humour, ridicule and rage.

"We need to take Islamic State on using technology, reason, humour, ridicule and rage" Nick Clegg

Recently, a rebel group fighting against IS in Syria captured a number of their fighters and dressed them up in orange jumpsuits for what appeared to be a bloody IS-style propaganda video. But instead of executing them, one of the rebels delivered a lecture on the value of mercy in Islam. The fighters were then reported to have been jailed — not beheaded.

Some months ago, referring to IS on the Channel 4 show The Last Leg, comedian Adam Hills declared that “we need to start ridiculing these pricks”. He asked his viewers to tweet in new names for them, and chose in the end to refer to them not as ISIS, but as Cystisis. It immediately caught on.

The brilliant response — “you ain’t no Muslim, bruv” — from a witness to the knife-wielding attacker in Leytonstone Underground station earlier this month captured a note of defiance, contempt and humour better than any government strategy ever could. It gave people the confidence to laugh at what they fear.

So let’s stop playing Whack-a-Mole and challenge people who say things we find offensive instead. Let Tyson Fury be in Sports Personality of the Year, just don’t vote for him (I’ll be voting for Jess Ennis-Hill, a superb role model who so happens to live in my constituency). Let Donald Trump in if he wants to come. I’m sure a queue of Brits will be waiting to take him on, myself included. Let Germaine Greer speak at university campuses, but don’t let her go unchallenged.

Free speech is the antidote, not the cause, of unpleasant opinions. Let’s beat, not ban, the views we don’t like.