Laurie Penny: This is what feminism needs right now

Being a feminist this summer is pretty exciting. It's like we've all been at some dull charity drinks reception and someone has hit the lights, jacked some power ballads into the speaker system and said: ladies – let's get messy.

First, there were the SlutWalks, when all at once, as if from nowhere, brave, angry women all over the world were standing in their scanties in the street, screaming about sex and class and patriarchy.

Now there's How to Be a Woman.

Caitlin Moran's new tome isn't your classic feminist handbook. It's as much about taking ecstasy and being a gobby teenage music journalist in the 1990s as it is a total rundown of the existential dilemmas of western womanhood. It's the gutsy, smutty autobiography of a rockstar feminist, exquisitely well-written, stained with fag ash and memories.

Really, this book would have been better titled How to Be Caitlin Moran. It's not the story of everywoman, but of one smart, successful middle-class British woman who grew up poor and overweight and now gets paid a great deal of money to be knicker-wettingly funny about a lot of important things. And that's precisely what makes it so brilliant. It's a powerful and, one suspects, deliberate riposte to the ghastly ghostwritten memoirs of "role models" such as Katie Price, who Moran describes as "Vichy France with tits", at which point I punched the air, alone with the book in my bedroom.

This book is funny. Like all the best feminist writing, it laughs in the face of power. Even better, it's dirty. Sex oozes out between the pages. I'm talking about real sex: not the boring, sterile porn producer's vision of female sexuality that Moran critiques, nor the staid Carrie Bradshaw model whereby one is only allowed to fuck in $500 Manolos, but real sex, all smut and silliness and horny teenage wanking sessions with one eye on an unlockable bathroom door. It's like My Secret Garden as written by Lady Gaga in a skip in Wolverhampton, with knob gags.

The filthy glee with which Moran describes her mattress-cracking desire for her own husband, the shuddering frustration with which she declares that she just wants to see, somewhere on the internet, a video of an actual woman having an actual orgasm, is compelling precisely because it is so rare. This is what feminism needs right now. Not another boring list of timid complaints, nor a pinkly patronising explanation of why you don't have to stop shaving your legs just because you believe in equal pay – but a bit of filth, a bit of hope, and a lusty bucketful of courage. This book is not a revolution, or a call to arms. It's a paperback. But it's a damn good start.

Selma James: Moran doesn't want to change much

The book intrigues potential readers with its description as a rewrite of The Female Eunuch ("from a bar stool"). But this sets a standard that can't easily be reached, even in comedy. Germaine Greer gave us a major compilation of outrageous words and acts suffered by women. Some of Moran's best prose describes how terrific it was to read this 1970 book – the female fruit of the 60s, heralding the birth of an autonomous women's movement for liberation.

But in the 21st century, when all women have been touched by that movement, feminists such as Moran seem to be isolated in their (western) sector, not in any way connected with the rest of us. Having arrived in a man's world, they discover they have not shaken the "problems of being a woman": even "famous and powerful women are constantly pilloried for being too fat or too thin, or badly dressed … " – and worse.

In fact Moran is speaking to a widely expressed dissatisfaction among women who have found with consternation and sometimes fury that even at the top they are not free of sexism. Their problem is, they live in the same world as the rest of us, where, for example, there is little progress in pay inequity; where 6.5% of reported rapes end in a conviction on the charge of rape (and between 75% and 95% are still unreported); and where the only move to equity with men is a rise in the proportion of women prisoners, and in the pension age.

Some women with social power complain about these injustices, especially if directly affected by them, but most have not considered that they have to do anything for other women to save their own position in society, let alone their feminist souls. It is just not possible for any women to be "making their own fate", as Moran claims, while the rest of us are condemned to a never-ending day of waged and unwaged slavery.

Moran says feminism is "the belief that women should be as free as men … ". But Greer knew that the "first significant discovery we shall make as we racket along our female road to freedom is that men are not free … ". Greer concludes with a call for revolution and for women to withdraw our labour. Moran doesn't want to change much. She doesn't seem to know that no one will be free until all of us are. The closest we can get to freedom is fighting for it with whomever is as eager as we are to achieve it. Which feminists are with us?

Zohra Moosa: In her hands, pop culture becomes a manageable beast

Deliberately irreverent to the point of distasteful absurdity at times – likening too-small pants to the partition of India and Pakistan, for example – How to Be a Woman is still a read worth making. Why? Because it bridges the strident and the practical by being really very funny. Unapologetically feminist, Moran makes short work of women who struggle to lay claim to the label – it is a benefit of feminism that women can publicly debate the benefits of feminism.

I can't relate to all of Moran's experiences (having not grown up very poor on a council estate in England for starters), but I found myself sympathetic to her views. She suggests asking "Are the boys doing it?" as the basis of a misogyny meter fit for the much murkier waters of stealth sexism that now surround us. At a time when it can sometimes take us a minute to realise "That was sexist!", reminding ourselves how differently men would fare in the exact same situation does help focus the mind.

But the book wasn't one big yes for me. One weak point was suggesting that "manners" are a feminist's best shield. In an attempt to be practical and accessible, I presume, Moran partly paints feminism's big aspiration as wanting everyone to be polite to each other. Obviously I understand that couching a request for (basic) respect in a cloak of civility can be politic. But very little attention is paid to how we move from etiquette to tackling the ongoing gender pay gap, women's under-representation in politics, unequal divisions of domestic labour, and violence against women and girls. Though these links aren't very clearly made, the book does offer a workable answer to one niggling question: why haven't women got on better since they got the vote? And this is where the book sings for me: in Moran's hands, pop culture becomes a manageable beast whose trends women can embrace or reject with clear eyes.

Not quite as deeply insightful as Greer's Female Eunuch was for its time, How to Be a Woman does convincingly poke fun at the myriad methods of patriarchy, and cheerfully explain why Moran is not so secretly up for a feminist revolution where women finally have a go at running things.

Bella Mackie: Force it into the hand of every teenage girl

Caitlin Moran begins by referencing the diary she wrote as a 13-year-old. By the end of the first chapter I realised that, at 27, I had come to this book 14 years too late. This is precisely the kind of book that should be forced into the hand of every girl on the brink of angst-ridden adolescence by parents who know what horrors are coming.

Notwithstanding the title, Moran is not inventing a new or achingly pretentious theory on feminism, and she isn't passing down edicts or dictating that there is merely one way to be a woman. She is above everything, trying to set out (and dispel) the misguided worries women grow up with. Most importantly, she does this with easy humour.

Everything from weight to sexual exploration is covered, subjects she sets out using bluntly honest personal experiences that made me nod along with worrying frequency. Her internal monologue as a teenager sounds uncannily like mine back then and the worrying revelation here is that, even at my age, this surprised and heartened me. Girls don't discuss this stuff, they keep their heads down and try to blend in with their peers.

In this world, feminism isn't a concept uttered much. Schools often present feminism as a hazy historical concept revolving around women jumping in front of horses and generally outraging the sensibilities of upper-class gentlemen. Moran argues persuasively that feminism is still needed, with this most pared down reason to join the sisterhood: do you have a vagina? And do you want to be in charge of it?

Answering yes doesn't mean burning your bra (as Moran says, we love our bras), it means wanting to be as free as men are. It also disregards the accusation that feminism means hating men. If there's one thing this book shows, it's that the negative connotations attached to feminism are by no means applicable when you use Moran's reasons to be one.

Perhaps it would be cheating to hand this book to a teenage girl and allow her to bypass all the misery to come. Sadly, you probably have to learn to do this yourself, if only for the smug moment when you realise you don't care what some magazine says about celeb diets or your thighs. But buy it for your teenager anyway – if she's anywhere near as smart as Moran, she'll thank you after the decade of screaming matches and wildly inappropriate clothes.

How to Be a Woman by Caitlin Moran, is published by Ebury Press on 16 June at £11.99. To order a copy for £9.59 with free UK p&p go to Guardian Bookshop or call 0330 333 6846.