Last week, the actor, writer and director Lena Dunham sent out a provocative tweet to her 5.5 million followers, while frustrated at a flight delay in JFK.

The creator, writer and star of the HBO series Girls, believed she had earwigged on a conversation that deserved to be “called out” on social media – the supreme court of public opinion.

Her tweet read: “Just overheard 2 @AmericanAir attendants having a transphobic talk. We should be teaching our employees about love and inclusivity.”

This was an arbitrary, unfounded accusation, against two humans who have nothing to do with her, and who are – trigger warning! – fully entitled to think what they like; totally free to have a personal conversation about whatever they please.

But in Dunham’s world opinions and thoughts that don’t align with hers need to be shut down, in an approach that wouldn’t be out of place in the censorship culture of East Germany.

There was no proof provided. American Airlines later said that the times and places didn’t match up. They don’t fly from the terminal she was flying from. They were “unable to substantiate” her allegation.

Clearly, she couldn’t miss the opportunity to jump on board the most current, right-on cause. It showed her up to be, at best, incoherent, and at worst wrong.

Stifling free speech

Her actions represents a hijacking of true liberalism that has its basis in stifling free speech. Those who really are liberal – definition: willing to respect and accept behaviour and opinions different to our own – must fight this pervasive belief system that is threatening the most cherished of all liberties. Otherwise we are rolling back decades of progress that has created a western world where free speech is one of the fundamental tenets of society.

Why is is now acceptable for certain political groups to shout down and shut down anyone who isn’t in agreement with their orthodoxy?

Not gonna call out the airline who delayed cuz shit happens BUT I did just overhear 2 @AmericanAir attendants having a transphobic talk. — Lena Dunham (@lenadunham) August 3, 2017

Why is it coming from the left, not the right. The branch of politics we should be able to trust seems to have largely forgotten that tolerance and equality cannot be parsed.

In the process it has alienated good people with diverse opinions and important minds. Rather than debate, many people now say nothing. Instead, they keep their thoughts to themselves. The space for intellectual debate is reduced. But a society without an open and honest debate is one that is more likely to turn to violence.

Political correctness, a stultifying, boring, self-righteous and prissy movement that patronisingly assumes everyone is a victim, began as a good idea to protect the vulnerable in society. Now it is silencing dissenting voices of any kind. What started as awareness and education has morphed into finger-pointing and thought-policing.

But if people don’t feel free to tell you what they are thinking, how can you confront them? How can you change the other person’s mind if their voice is not allowed to be heard?

We cannot confront racism, discrimination and prejudice without first knowing they are there. We cannot develop certainty in our own convictions, unless we have had them challenged.

The smothering of free speech is being carried out in a very modern way and appears to be the preserve of naive activists.

In the media, it’s about wilfully conflating opinion with news. It’s about reading the headline and deciding you’re offended, without any context, and instantly labelling the target sexist/misogynistic/homophobic/racist, delete as applicable. It’s lazy and it’s anti-intellectual.

On campus, it’s about protesting against talks at universities until they are called off for security reasons, and bleating about “no-platforming” – censorship by another name.

Lynch mob

It’s about setting a lynch mob on social media, calling for the sacking and destruction of people with whom you do not agree. Making them social pariahs, or turning an individual with the brain to question a contentious issue into a bad guy.

It’s creating a climate of fear so that those few brave enough to do the important job of putting a voice to what many people are thinking – but are afraid to say – are intimidated and cowed.

And ultimately there is a reaction. Irish-American satirist Bill Maher believes that the backlash against this forced thinking and free-speech stifling has resulted in “a madman in the White House”.

Talking about the importance of freedom of expression, he said: “The Democrats have gone from the party that protects people to the party that protects feelings. Liberals do this all the time. They get offended for people who themselves wouldn’t be offended.

Nearer home, Rory O’Neill, whose alter ego Panti Bliss was the figurehead of the marriage equality referendum campaign, is similarly minded and argues an inclusive society is one in which we all have to accept a difference of opinion. “If everyone feels browbeaten into acting the same, we lose the creativity of difference. I think it’s absolutely fine if an evangelical Christian dislikes homosexuality. I just don’t want them to try and make everybody else be the same as them.”

The lesson is simple: let those with dissenting views speak – you might learn something.

Larissa Nolan is a journalist and commentator