I recently spoke at the annual conference of the UK’s Girls’ Schools Association (GSA). I went to a co-educational comprehensive and am agnostic about single-sex education. As a result, I found the prospect of addressing a room full (largely) of headmistresses a daunting task. I readily agreed, however, because I had been asked to talk about how to encourage girls to take debating seriously.

First, a declaration of interest: the Institute of Ideas, of which I am director, runs a UK- and India-based debating competition for sixth-formers called Debating Matters. It differs from the debating practised in traditional schools by emphasising substance over style: less rhetorical cleverness, regardless of the topic; more well-researched argument about real-world current affairs. It aims to be tough. After their initial presentations, debaters are cross-examined by expert adult judges and thoroughly interrogated about their arguments. In this meritocratic and challenging format, gender seems to be irrelevant.

However, I am sensitive to the idea that girls can sometimes find their voices drowned out, or at least sidelined, by their louder, more boisterous male peers. Therefore I’m keen to encourage young women to give as good as they get and to challenge any stereotypical ideas that they are the quieter, fairer sex, unable to compete on a level playing field when it comes to debating or arguing their corner.

This year’s GSA conference identified six “constant values” for “changing times”: resilience, leadership, integrity, confidence, independence of thought and compassion. In terms of encouraging girls to debate, resilience and independence of thought in particular are key qualities and served as a useful measure for my musings.

So let’s consider the intellectual landscape that young women confront today when it comes to finding their voices. On the face of it, the climate looks hospitable. Over recent years, there seems to have been an upsurge in feminist-like campaigns that focus on encouraging girls to speak out in the public sphere, all attracting a youthful demographic and claiming to be giving young women space to make their views heard and matter.

Take UK Feminista, founded in 2010 and now a “leading national voice.a powerful force for change”. Its director, Kat Banyard, boasts of “a new movement.gathering pace.brimming with energy and excitement”.

Or there’s The Women’s Room, set up “to provide women with a collective voice” and better representation of women in public discussion: “Women have far more power than we - or the media - currently realise. Let’s harness it and change the face (and voice!) of the world.”

However, it is dispiriting to discover when you scratch the surface that the fashionable causes espoused by these new groups are far too likely to teach young women lessons inhospitable to encouraging resilience. Worse, many have missions seemingly hostile to free speech and open debate, both key ingredients for fostering independent thinking.

Although some commentators were excited earlier this year that Girlguiding UK has at last embraced the feminist cause by adopting the No More Page Three campaign as an official policy, I cannot cheer that 88 per cent of a poll of 2,000 guides aged 16-25 voted that The Sun should stop publishing photos of topless models. After all, while “Boobs aren’t news” might be a witty-ish slogan, in the end this expresses a censorious instinct to ban what we don’t like.

Neither can I bring myself to cheer the likes of the students from Camden School for Girls who are backing the fashionable #losetheladsmags campaign. It may look very daring for schoolgirls to take on a corporate giant such as Tesco when they demand that the company stop one of its shops selling “degrading lads’ mags” like Zoo and Nuts. But the sixth-formers’ objections betray a weirdly prurient tone and a disturbing enthusiasm for illiberal bans.

When these 17-year-old campaigners tell their local newspaper how “appalled” they are to have to confront “front-page women in underwear showing their cleavage” when buying their lunch, isn’t there a danger that this counterproductively fuels stereotypes of young women as weak and fragile creatures? They say they want the magazines removed because “it is inappropriate to have them opposite a girls’ school where the majority of girls say they are very damaging to them”. But are today’s young female warriors really so lacking in resilience, such sensitive wilting violets, that their self-esteem will be damaged by a few topless pictures? Pass me the smelling salts!

Culture of complaint

My fear is that those students who are getting their voices heard are doing so less to cry freedom and more to cry “Woe is me, I’m a victim, I can’t cope”. And they are being tutored in this passive, victimised role by initiatives such as The Everyday Sexism Project, which encourages us all to email in “instances of sexism experienced .”, making no distinction between the “serious or minor, outrageously offensive” or just “so niggling and normalised that you don’t even feel able to protest”. The danger here is of encouraging a disproportionate response to relatively harmless if unpleasant and distasteful comments and behaviour, and encouraging a culture of complaint.

All this feeds into the contemporary politics of offence, which has had a chilling effect on public debate more broadly. This new thin-skinned attitude is particularly toxic when mixed up with new forms of highly subjective identity politics. That ubiquitous phrase “As a female, I find that offensive” is too often used as a way of silencing opponents. It inevitably encourages an unhealthy sense of vulnerability, always seeking to be protected, to claim hurt, too quick to reach for the “report abuse” button.

This is nowhere more evident than in the feminist-inspired witch-hunts against sexist trolls on Twitter, regularly demanding that these pathetic, foul-mouthed saddos be silenced in the most authoritarian way, often insisting that the police arrest or even imprison culprits for what is in effect a “thought crime”. How ironic that censorship was historically used as a weapon against those who fought for women’s rights; that our 19th- century sisters were arrested for distributing literature that was deemed offensive in its day on topics such as contraception.

I am not sure if I will be invited back to the GSA, but my message is more broadly that what we should be teaching today’s girls - wherever they are educated - is that you can’t fight for liberty for women if you deny it to others or demand a voice for women by silencing opponents.

To girls, I want to say: avoid campaigns that encourage you to complain that you’re not resilient enough to deal with other people’s words, verbal attacks or even insults, because inevitably such concessions denude you of your most important weapons: argument and intellect. My advice is to learn to debate, to practise the art of intellectual pugilism. Be prepared to robustly interrogate others’ views, but in turn develop a thick skin, be resilient enough to take criticism and defend your ideas without fear. Good luck.

Claire Fox is director of the Institute of Ideas.