One of the greatest victories of the feminism of the 1970s and 1980s was to show the world that the personal was political. The intimate underpinnings of human existence, from sex and romance to child-rearing, drudgery and domestic violence, were not just private, irrelevant women's issues: they were essential to political and public life. Unfortunately, over the past two decades, the trajectory of women's liberation in public discourse has undergone something of a reversal: instead of making the personal political, the political has, slowly but surely, been permitted to collapse into the personal.

In a culture where debates about cupcakes and pubic grooming are still top priority in fashionable feminist circles, Naomi Wolf's new book, Vagina, seems to represent the apotheosis of that philosophy. Going by the extensive interviews and extracts being serialised this week, Vagina focuses on the author's recent difficulties achieving satisfying orgasm and subsequent treatment for a trapped nerve in her back, and attempts to extend the lessons of this minor surgery, beyond "private doctors are wonderful if you can afford them", to the entire female experience. In this case, the entire female experience seems to apply only to wealthy, straight, successful, cisgendered white women living in New York City. One extract centres quite seriously on a dinner-party incident where the host served uncomfortably yonic handmade pasta. I wish I were making this up.

Naomi Wolf is a fine and thoughtful writer, and has been an important voice for over 20 years. The Beauty Myth remains a classic for a reason, and I'm one of millions of women who have been inspired by her ideas. However, when a global crackdown is under way on female sexual and reproductive rights and women still do most of the work in most societies for low-pay or no pay, you'd think the most anticipated feminist book of the year would be marketed as having a little more to contribute.

Wolf's basic contention that female sexual pleasure is both important and undervalued is sound. It seems, however, to come packaged in a great deal of toe-curling, cod-scientific claptrap about how every woman's spiritual power is located between her legs and zooms up an "electric inward network extending from pelvis to brain". Claims that the vagina is "not only co-extensive with the female brain but also is part of the female soul" are frankly offensive to anyone who believes that the most politically important part of any woman's body is still, is always, her brain.

Naomi Wolf is far from the only eminent writer to have been lured by sweet-but-silly yoni-centric feminism. One almost longs for the days when liberal, middle-class feminism was merely navel-gazing: now the collective gaze seems to have been drawn six inches lower. Unfortunately, any women's liberation project that fails to link its analysis of sex and gender to class, economics and structural violence is doomed to spiral into anxious self-regard, and today's young women deserve better.