A couple of years ago, Naomi Wolf signed up to write a book about the vagina. "I was euphoric, in creative terms … At the same time I was anxious about grappling with such a strong social taboo." A friend of a friend – "an impresario whom I will call Alan" – throws a party for her in his loft, "a pasta party at which guests could make vagina-shaped pasta", an idea Wolf says she finds "funny and sort of charming" though "not a thematic twist I would have chosen for myself".

At the party, "there was a slightly ominous, mischievous stir" from the kitchen, where guests have been hard at work: "Flowery or feathery, fluted or fanned, each small sculpture was detailed and different: lovely little white objects against a hand-painted blue Italian ceramic tray." "I call those 'cuntini', says Alan, laughing." "My heart contracted," Naomi responds. Next, she hears a sizzle. "I got it: ha, sausages … The room had become tense." Then comes the salmon. "I flushed, with a kind of despair," she writes, adding that the evening as a whole left her so upset, she was unable to write a word of her vagina book for the next six months. "I felt – on both a creative and a physical level – that I had been punished for 'going somewhere' that women are not supposed to go", she writes.

"A Rorschach with legs" is what Natalie Angier calls the vagina in her superb Woman: An Intimate Geography (1999). "You can make of it practically anything you want, need or dread." And the same is true, surely, of this sorry tale. Different readers will have different cringe-points, different places in the story at which they start shouting "Whoah!" You may be appalled at the thought of a book called Vagina in the first place. How backward-looking, how attention-seeking, can a 21st-century feminist get? You may be fine with vaginas in a book title, less so as a shape of pasta – most people avoid close-up genital chit-chat in mixed culinary situations, and there are obvious reasons for the taboo. You may find the pasta in theory, as Wolf did, "sweet" – a quick google brings up vagina cupcakes, pink felt vagina knickers, a commercial range of tricolore pasta from Naples cut in genital shapes – but it's the c-word that upsets you, or the sausages, or the fish. Personally, I particularly disliked the "impresario whom I will call Alan", and the "hand-painted blue Italian ceramic tray": ugh boasting, ugh sentimental, ugh ugh. I'm not keen on the post-party six-month trauma either. If you're a big enough show-off to have a vagina-pasta party in the first place, I kind of feel you've abjured your right to victimmy tender-plantdom. No doubt that says as much about me and my hangups as it does about anything else.

"I was aware," Wolf reports, that when she told people about her topic, "many people had immediate, probably measurable physical reactions." Some "smiled immediately, beautiful heartfelt smiles". Others "looked frightened or disgusted, as if I had suddenly produced from my handbag a trout". Neither covers my own reaction, though it was closer to Monty Python fish-slapping than the heartfelt-smiling thing. I admire, of course, the force-of-nature whorls in the paintings of Georgia O'Keeffe, the magnificent White Hole by Rohan Weallaens in his show with Sarah Lucas, currently showing at Sadie Coles HQ Off-Site. But Judy Chicago and her Dinner Party, Eve Ensler and her Vagina Monologues – it's wretched stuff, po-faced and self-righteous, all the very worst bits of 1970s feminism rolled up in a tube.

It's not that it isn't possible to do really excellent work with lots of vaginas in it. Angier's survey, for example, is the book I'd give free to every schoolgirl if I was Michael Gove. Catherine Blackledge's much-overlooked The Story of V (2003) is lucid and thorough, and has some amazing illustrations. On the vagina as symbolic object, The Female Thing by Laura Kipnis (2006) is a sharp, funny, leftwing, Freudian essay about the many ways in which "having one of these things instead of one of the other things … invariably structures the female experience here on earth". Most recently, Florence Williams writes in Breasts: A Natural and Unnatural History (Norton, 2012) about how the life of organs commonly thought of as private is always socially and environmentally conditioned, by the fantasies in the ether around them, by the chemicals they absorb.

Wolf's book, however, is something else again. Yes, it does a bit of science, and a bit of cultural history too. But mostly, it doesn't need to, because Wolf has found a magic key. "The vagina and the brain," Wolf has discovered, are "essentially one network, or 'one whole system'", though at the moment, not a lot of people know this, apart from "scientists at the most advanced laboratories and clinics around the world". Taken together, this "profound brain-vagina connection" forms "a gateway to, and medium of, female self-knowledge and consciousness", mediating "creativity and transcendence". You thought Angier was laying it on a bit when she poeticised the vagina as "a pause between the declarative sentence of the outside world and the mutterings of the viscera"? Well, for Wolf it channels "a sensibility that feels very much like freedom". Or if that's too much to deal with, just look on it as "essentially part of the female soul".

This discovery, Wolf writes, "started as a historical and cultural journey, but quickly became 'personal and necessary'". In 2009, she says, when she was 46, her life was outwardly great (aren't they always in this sort of story) – "emotionally and sexually happy, intellectually excited, and newly in love". And yet – as is the convention – "something was becoming terribly wrong". In her 40s, she explains, Wolf had felt her experience of orgasm deepen and become enriched, leading her to "see colours as if they were brighter" and "the connections between things" more distinctly. In 2009, though, "this was changing. I was … losing sensation inside my body." Worse, her sense of the "poetic dimension" was disappearing too. "Things seemed discrete and unrelated to me … and colours were just colours." She gets depressed and then despairing: "It was like a horror movie, as the light and sparkle of the world dialled downward and downward."

It turns out that Wolf has trapped a nerve in her lower back, between the lumbar region and the sacrum. Normally, this "pelvic nerve" carries messages between the brain and the clitoris, cervix and vagina, but in Wolf's case, because of the neural damage, the messages from the vagina were cut off. And yet, she still orgasms from her clitoris, no problem. "Every woman is wired differently," her specialist explains. "Some women's nerves branch more in the vagina; other women's nerves branch more in the clitoris … That accounts for some of the differences in female sexual response." "I almost fell off the exam table in astonishment," writes the author. "That's what explained vaginal versus clitoral orgasms? … Not culture, not upbringing, not patriarchy, not feminism, not Freud?"

Once she has picked herself up again, Wolf organises her argument round two main strands. Science, she discovers, has been making lots of progress in understanding the physiology of female sexuality, but nobody tells us about it. "Why didn't they tell us in eighth grade? … It's changed my whole sense of how we're put together," as she said to Emma Brockes in the Guardian this week. But also, this vagina-brain connection has an emotional, even spiritual dimension – "a 'hole'" that is "Goddess-shaped", no less. She gets surgery to put her back right, and finds her full-spectrum orgasms restored, and with them, the mystical intimations. "The moving grasses, the sweeping tree branches, the birds calling from invisible locations in the dappled shadows … I thought: it is back."

The first part of the book is called "Does the Vagina Have a Consciousness?" Wolf's evidence includes neuroanatomy – "your dreamy autonomic nervous system, or what scientists call the ANS" and neurochemistry – "the dopamine, oxytocin and opioids released by (the) orgasm, which in turn affect (the) brain". The take-home is basically that just as sensation runs from pelvis to brain, so it runs the other way as well, meaning that "gestures, touches, kisses and words aren't extras. They are integral parts of the activation of the female ANS." In other words, Wolf thinks that the sort of sexual pleasure the modern woman is encouraged to seek is far too wham-bam to release women from what she sees as a widespread "existential depression", an "An Epidemic of Female Sexual Unhappiness".

Much of this "sexual suffering" Wolf thinks has been systemically imposed on women, across the world and down the centuries: rape and genital mutilation, military, judicial and ritual. "If you are to subdue and suppress women, and in such a way that they come to do it to themselves …. you must target the vagina." There's also an interesting bit on the threat posed to the "happy heterosexual vagina" by internet pornography. The evidence isn't entirely there yet, but Wolf's argument that heavy porn use seems to follow an addictive pattern, desensitising users to images of violence and causing them to lose interest in affectionate sex with a partner whose name they know, seems increasingly plausible. Though I'm not sure about the impresario-I-will-call-Alan foodie spin: "The mass-produced, fast-forward, pornographic vagina is to the real vagina what highly processed or GMO food is to slow or organic food."

More surprisingly, she also blames "second-wave feminism", ie, the work of the early-1970s Women's Liberation Movement. In The Myth of the Vaginal Orgasm (1970), she says, Anne Koedt argued that "Freud's elevation of the vagina over the clitoris" was a "patriarchal plot" in order that women be "brainwashed into dependency on men". An understandable move, Wolf thinks, but overstated, and with unfortunate consequences: "From the 1970s on, the vagina was recast as rather retro, housewifey and passé", whereas the clitoris was "a glamorous, mini-skirt-wearing Gloria Steinem".

But mainly her target seems to be ordinarily lazy boyfs and hubbies, who, she thinks, have to try much harder when appeasing the "entirely different model of female sexuality" she dubs "the Goddess Array". The quest takes her deep into the erotic texts of the Tantric, Tao and Islamic traditions. It takes her to a shabby hotel in Midtown Manhattan for a weekend workshop in "sacred-spot massage" run by "the surreally juicy" Caroline Muir ("While all of the women were conventionally attractive, many of the men were not at all"). It takes her to Chalk Farm in north London to visit Mike Lousada, "the world's nicest former investment banker turned male sexual healer", famous for having once stared at "the yoni" for so long, he saw an image of the Virgin Mary in it. If you want your own "sacred spot" expertly rubbed by Muir, Wolf tells us, the hourly rate is $250. Lousada, by contrast, charges only £100.

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I read this book in utter bafflement. What is this big news that Wolf has to impart? Vaginas feel stuff, so yes, of course they must be packed with nerves; and nerves, we know, join up with each other at the spine to link into the brain. That's why they call it the central nervous system; that's what being human is all about. Feet, too, join up with the CNS – thus reflexologists, and why bunions are so painful. And so do the intestines, giving rise to the extremely interesting "Gut Feminism" of Elizabeth A Wilson at Emory University in Atlanta – digestive organs as "psychically alive", "the enteric character" of mood, "how biology can be an ally for those of us building models of mind-body that tax the limits of Cartesian dualism". In other words, the closer you look at attempts to argue that mind and body are not completely wrapped up in each other, the more you will see all sorts of connections, biological and symbolic and liminally teetering in between. "Having a body punctured by so many openings and canals," Kipnis writes, "blurs the distinction between inside and outside, self and world. The apertures invariably take on emotional resonance … She's so 'open'. He's a real 'tightass'." And of course the c-word, in all its abject force.

At the beginning of her Vagina book, Wolf says that her theory of "biological consciousness" comes in part from William James's mighty The Variety of Religious Experience (1902) – "the issue of neurology as a substratum for these common mystical experiences", ie, that particular brain-states may give people a feeling that they are, for a moment, in touch with God. After that, though, she doesn't mention James again. Which is a pity, because one great thing about the James book is the way he doesn't pooh-pooh these passing feelings, while also recognising that any individual attempt to "locate" them can only end in idiotic hubris: "We must frankly recognise the fact that we live in partial systems and that parts are not interchangeable in the spiritual life." Those selfish genes with their shoulder-pads, grabbing evolutionary advantages for the alpha males; dopamine and oxytocin, gambolling like SpongeBob SquarePants round the reptile brain; the stories told by the popular-science writers can only ever just be stories, partial facts filled out with cartoonishly consoling fictions.

So yes, body and mind are completely part and parcel. But no, this doesn't mean the connections are easy to conceptualise: neither goddesses nor Numskulls nor ghosts in the machine. Remember Wolf's "astonishment" when her doctor told her that every woman's pelvic wiring is slightly different? She should be more than astonished, I feel. She should be daunted and delighted at the great polymorphous cloud ahead of her, every individual equal and yet completely different – vagina and/or clitoris and/or all of these or none; fingers and/or penises and/or hair dryers and/or veg. But Wolf does not want to think about such glories. "One of my primary themes is the exploration of heterosexual women's physical and emotional interactions with men … Not because I think that lesbian and bisexual arousal, orgasm, relationships or mind-body connections are any less fascinating," but because women are "so complex and so worthy of careful, individualistic attention that I do not believe that the politically correct approach of lumping all female experience together … can do justice to the variations of female sexualities and their emotional counterparts." Lesbians, anuses and Betty Dodson do at least get passing mentions. Asexuality, blowjobs, sexual fantasy, do not figure at all.

The pulsing cloud becomes particularly shrunken in the neurochemistry chapter. "People differ from one another at every juncture of the dopamine matrix," Angier wrote of "today's It-neurotransmitter" a few years ago in the New York Times. "In the tonal background pace at which their dopamine neurons rhythmically fire, the avidity with which the cells spike in response to need or news …" For Wolf, on the other hand, dopamine is simply "the ultimate feminist chemical in the female brain". Whereas serotonin emerges as a baddie, particularly in its most famous role as the brain-chemical boosted by popular SSRI anti-depressants such as Prozac. "Women far outnumber men in being prescribed SSRIs. Are these same millions … warned that SSRIs may well send their libido and ability to experience orgasm plummeting?" ("Low sex drive", I read at second place on the "Common Side Effects" page on the NHS Choices website. Wolf may be appalled that many women seem resigned to sexual self-bludgeoning in exchange for the basic ability to keep going, but a lot of evidence suggests they do.) Oxytocin, best known for its part in stimulating childbirth and lactation, she dubs "the cuddle hormone" and "women's emotional superpower". Top advice for women who "want to have hot anonymous sex with some guy … but don't want to fall in love with him … discourage him from interacting with their nipples." Because if he does get his hands on your boobies, you'll have to marry him, obvs!

The stuff about rape and sexual violence is just strange. Wolf's main argument – that rape is at least half-consciously a subordinating tactic deployed by men – has been feminist orthodoxy since 1975, when Susan Brownmiller published her canonical Against Our Will: Men and Women and Rape: "From prehistoric times to the present, I believe, rape has played a critical function. It is nothing more or less than a conscious process of intimidation by which all men keep all women in a state of fear." And yet, Wolf says that Brownmiller, like others of her generation, writes about rape while following an "individualised reading of sexuality posited by Freud", which is surely just not so. Wolf's take on classic women's liberation in general is perverse. Koedt, it's true, did mistakenly write that "the vagina is not a highly sensitive area" in her legendary paper. But her main thrust was to open, not close, sexual possibility for women; besides which, other feminists just went as fancy took them. Germaine Greer in 1971, for example: "To develop the muscles of the pubococcygeal region, think of something nice and contract the buttocks rhythmically … You might even succeed in making the whole pelvis awake to love and beauty."

As for this "gendered sense of self that is shining, without damage, without anxiety or fear", this "radiant part of the universal feminine" that is activated by obeisance to the "Goddess Array" … What if you're a woman who practises forms of sex that bypass the vaginal? What if you were born without a vagina, or with two vaginas, or have a female-looking vulva, but are intersex inside? What if you are biologically and culturally female, but want to smirk or vomit at the very thought of a "Goddess" anywhere near you? What happens to "the universal feminine" then?

Naomi Wolf, presumably, is like many of us, a middle-aged woman who has been thinking a lot about spiritual matters, as middle-aged women often do. Her body has been changing – which also happens – and in her case, she's also had that miserable injury, which yes, I can see would make you look at your sexuality anew. But it takes a particular way of looking at things to extrapolate from that to the shining Goddess. Wolf, this book tells us, has also been looking at images of sexual awakening in Christina Rossetti and Kate Chopin, because she has recently gone "back to graduate school". And discussing orgasmic rats with "a group of brilliant young women" at "a cottage on an old farm". Chatting with Mike Lousada for "a London newspaper". And visiting, in 2004, a refugee centre for women raped during the civil war in Sierra Leone. All evidence, one way or another, for this spiritual-emotional-neurological network. All of it really just connected by the life, the interests and the ego of Naomi Wolf herself.

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Back in 1990, I remember watching the young Wolf on television, with a panel of older feminist writers, discussing her first book, the bestselling The Beauty Myth (1990). These older feminists – I can't remember who any of them were – were being just horrible. Their gist was that Wolf, being 28 and good-looking and well groomed, had no right to speak out about any "beauty myth", or to call herself a feminist at all. Awful, I remember thinking, but also interesting – the way older women so often hate letting the younger ones have their turn. I wrote an article about it for a long-dead magazine called City Limits, which was where I was working, in my first London job.

And I guess that must be why I have a fuzzy memory of an evening shortly after, when Wolf came for tea to my Brixton house-share, together with my friend and then City Limits colleague, now Guardian columnist Deborah Orr. It was a nice evening, I remember; I made a huge spanakopita and Wolf was lovely. Only then, Deborah or I said something mildly critical of some point or another, and Wolf fought back. The forcefulness, the mental agility, the lack of embarrassment! The sense of entitlement and mission, the self-belief! It was quite an insight into what it takes to be a celebrity feminist. I immediately saw that I would never cut it. And so, more than 20 years later, I'm still bodging my spanakopitas in south-east London while Wolf has long been a figure of world renown.

After The Beauty Myth, Wolf wrote a sort of sequel to it, Fire With Fire – her own attempt to work out why feminists so often seem to hate each other and what to do about it. The decade subsequent, she published three memoir-based personal-is-political numbers, Promiscuities – herself and her friends as teenagers; Misconceptions – as young mothers; The Tree House – as burnt-out middle-agers, a condition Wolf remedied by doing up her country house with the help of her old dad. Throughout, I watched her from a distance, observing how tough the job of celebrity feminist can be: you have to keep publishing and opining, no matter whether you have much you really want to say. You have to present your ideas to public scrutiny even if they're still half-baked. A single wobble, and the media will leap – do a google, for example, on Naomi Wolf-Katy Perry. Naomi Wolf-abortion-New Republic. Naomi Woolf-Al Gore-consultant. Naomi Wolf-New York magazine-Harold Bloom. Naomi Wolf-rape-Julian Assange. Then after The Tree House, Wolf suddenly moved sideways, with two plain, useful books on civil liberties and the right to protest in the age of George W Bush. Neither The End of America (2007) nor Give Me Freedom (2008) was published in this country, but readers will have heard about them when Wolf was arrested – in her evening clothes – at an Occupy! demonstration in New York City last year. (Good-oh, I remember thinking when I saw it. Now, though, I catch myself checking dates and wondering about the state of her pelvic nerve.)

Between jobs, I guess Wolf has never stopped trying to think big thoughts about women and politics and feminism. How some things change and others don't. How the same things need to be said afresh for every generation, and how hard it is to bear this, as you yourself get older and feel you've heard it all before. How much you'd like to warn the youngsters, except that all they hear when you try it is their utter conviction that they themselves will never end up like you. Exhaustion, irritation, frustration at all these goldfish-brain debatelets, repeating themselves, round and round. In a world with Jessie J and Jamie Clayton in it, Caster Semenya and the work of Judith Butler, why are we still letting one of the Anglophone world's most famous feminists waste everyone's time with all this burble about the "universal feminine" with its "Goddess-shaped" hole?

Funnily enough, it was on this very topic that Laura Kipnis's vagina book began. "Female progress – how's that going? Let's see. Gender barriers have largely crumbled (some exceptions remain), the dominant paradigms of patriarchy have mainly eroded (some exceptions remain), women have increasing economic dependence from men if they choose to (though many don't). But then you keep stumbling across the tracks of a certain … ambivalence. No, not the backlash against feminism – I mean the ambivalence among women themselves." For Kipnis, the big problem with feminism – an open, bold, modern movement, aimed at getting power for women, fair and square – is that it gets confused with femininity, an ancient, occult body of lore women use to trick men into looking after them; and few of even the most famous feminists have entirely clarified the difference. Or as Kipnis puts it: "Feminism ('don't call me honey, dickhead') and femininity ('I just found the world's best push-up bra!') are in a big catfight, nowhere more than within each individual female psyche."

Kipnis would probably see in Wolf's book just another iteration of the basic problem. The main reason for the current "epidemic of sexual sorrow" is not so much that "the vagina is being disrespected", but that women who should know better underestimate the complexity of Kipnis's "female thing" – "the female psyche of course", as Kipnis puts it, the experience of living with "this small furry thing" in a world that doles out privilege according to anatomy at birth. So yes, nobody disagrees that women are, on the whole, sad and rancorous, and that the problem amounts to what Wolf calls an "existential depression". If not the yoni, under the Tantric management of Mike Lousada, what other wisdoms are there to save us now?

"I had to say The Force," Wolf told the Sunday Times, when they asked for her favourite word for the vagina. And maybe it was that, or maybe it was the bit in Kipnis about the "small furry thing", but the vision that came to me at this point was the Star Wars poster on the wall of my son's bedroom, a picture of Yoda with a book tucked under his arm. "Read and The Force is with you," it says; it's an ad from the American Library Association. And also a reminder – not for the first time – that in the struggle for good sex over all the evils of the universe, the most potent and far-reaching weapons are not vaginas or any other bodily organs, but research, ideas, thinking – not yonis or even "the Goddess", but carefully weighed and thought-through words.