"It is fatal," Virginia Woolf wrote in A Room of One's Own, "to be a man or woman pure and simple." This phrase, repeated several times, might be thought of as the guiding sentiment of Unmastered, Katherine Angel's provocative and profoundly personal investigation into female desire. Angel's mission is to find a way of both inhabiting and writing about sexuality that offers a release from the corseting hand-me-down strictures of how a woman should behave. Desire, after all, is a form of hunger, and as such incompatible with the notions of abstemiousness and passivity that continue to burden the female mind.

Unmastered is constructed as a series of numbered aphorisms. Sometimes no more than three words occupy the page ("Am I pornography?"). It's a model that's found favour with a range of writers on sexuality, especially the transgressive kind, from Susan Sontag's seminal essay Notes on "Camp" to the cultural critic Wayne Koestenbaum's Humiliation. This laying bare of language is matched by Angel's radical unveiling of her own sexual life: the antics of what she beautifully calls "the lubricious body". She describes in graphic terms the act of sex, of touching and being touched, of having her breasts admired, of being tied to a bed with a belt by an unnamed lover.

It's hard to overestimate the riskiness of these passages, their courage and their exquisite sensuality. Angel deploys a range of voices, from the poetic ("a deep juddering pleasure, a ferry's heavy murmur") to the frank ("Fuck me. Yes, fuck me!"). There's a voyeuristic thrill to the exposure, a swell of reciprocal pleasure, but the real joy lies in the artfulness with which she uses these intimate episodes as a way of unwrapping the larger issue of what it means to be a woman, both object and subject of desire.

Angel is an academic at Warwick University, a researcher in the history of female sexual problems. As such, her investigations, while almost painfully intimate (one chapter is given over to the experience and aftermath of an abortion), occur within what is emphatically a larger conversation. She uses pared-down, poetic fragments from a multitude of fellow explorers  among them Woolf, Sontag, Susie Orbach, Havelock Ellis and Michel Foucault  as a way of building up a working map of sexual desire.

It quickly becomes apparent that to be true to one's sexuality means crashing up against pretty much all the forces invested in telling us what a woman should and shouldn't do. Does revelling in the pleasures of penetration automatically mean inhabiting the traditional female role of reassuring men, inflating them with a sense of their own potency? "Is this a compulsion to be what the other person wants?", Angel asks herself of her own desires. "I lock him into his masculinity. I am anxious to protect it, for it pains me, it pains my femininity, to see it fragmented." And, at the same time: "I am so fucking hungry!"

In her quest for sexual freedom, Angel more than once experiences feminism as an oppressive as well as a liberating force. In one amusing, troubling scene, she attends a lecture by the venerable sex researcher Shere Hite in which Hite and an audience member agree that lesbian porn using dildos should be boycotted. Later, she falls foul of another speaker at a feminist conference for raising the question of whether erotic images of female submission are automatically pathological evidence of patriarchal oppression.

On the other hand, she also challenges a male academic she nicknames Mr Pornography ("he has probably watched more pornography than anyone, anywhere") on his pro-porn stance, pointing out that despite his celebration of its democracy and inclusiveness, it still radically fails "to represent the nature, range and realities of pleasure in women".

Despite this latter comment, Angel's assumptions about sexuality tend toward the heteronormative and can on occasion feel a touch coercive. A statement like: "I was weaned on this  the hypostatised, brutal man; the yielding, deferring woman. So, by the way, were you" might be true in terms of the dominant culture but elides entirely the subtle shadings of sexual difference. This is particularly odd when so few of the writers she draws upon (Sontag, Woolf, Orbach, Foucault) can be categorised as entirely heterosexual.

Nonetheless, Angel makes a persuasive case for the idiosyncrasy of desire, its obstinate individuality. Caught between oppressive forces, her escape is by way of the sensual body itself. As such, Unmastered is a giddily joyful book, thicketed with exclamation marks. Days after reading, its images linger in the mind: an erotics that encompasses eating macaroons after an afternoon of bondage, or seeing a dead fox "on the southern underbelly of Peckham Rye, a restful body of red, a serene splash of white".

In its richness and its exultant tone, Unmastered frequently recalls another statement from Virginia Woolf's A Room of One's Own: "Who shall measure the heat and violence of the poet's heart when caught and tangled in a woman's body?" Woolf was talking about the fantastical figure of Shakespeare's sister but she might have found a more cheering answer here, in this elegant and uplifting journey through the labyrinth of female lust.

Olivia Laing is the author of To the River (Canongate £8.99)

Brevity is a big ask for a writer, not only because it demands purity of conception, but because it makes a bold claim to originality. A lavish arrangement of adjectives can do as much to perk-up a plain old idea as diamonds and lipstick can for a plain old face. It follows that few brief utterances are worth printing alone on the page. Hemingway's shortest story, consisting of six words:  "For sale: baby shoes, never used"  is one, because it's a well-constructed hand-grenade that requires a whole page for safe detonation. But Katherine Angel's brief musings, which tick and beep throughout Unmastered  "Fuck me, yes fuck me" is one example  regularly fail to go off.

Unmastered is a book about desire, formulated as a series of reflections, recollections, aphorisms and anecdotes, designed to gain depth and mount in significance in a style reminiscent of the female orgasm. The aerated form (there is a lot of blank space) does generate tensions and releases  though at times you need to turn the pages quickly to achieve them. But an early-stage feline analogy for Angel's unmet desire  "Restless, like the cat, when we put her on soft food for a week, and she paced the room  pressing her teeth into hard surfaces"  announces a distinctive sensibility.

One requirement of this most challenging way to write is that any figurative language that does appear must be immaculate. Recalling her youthful attitude of supplication, Angel asks: "That deity: what was it?", and answers: "A cultural soup of religions I never shared but was  born into." The surprising crouton image would not have satisfied the judgment of a poet. Neither would "The hulking monolith of politics gathers around you  pressing its hands over your mouth", because a monolith doesn't have hands and can't "gather", being a single object.

Academics aren't usually expected to apply themselves fanatically to writing well, but Angel, who is a postdoctoral fellow in the history of medicine at Warwick University, is not writing as an academic. As the climax to an anecdote "It was an afterthought. It wasn't the main act. Or even an act at all," employs the cheap adrenal thumps of advertising copy, or of Raymond Carver when he'd had too much to drink. And "Am I pornography?" is not an aphorism, even if it is printed on its own on a page. For ars this brevis, vita is not long enough. 

Angel also takes diaristic liberties. The one-pager "These woods are lovely dark and deep. / Lovely. Lovely. Dark and deep" is a deliberate misquotation from Robert Frost's poem "Stopping by Woods on a Snowy Evening". The presumption here is that a reader will experience a sufficient degree of fascination with Angel's subjective reading of the poem. This might have been justified by stardom or at least a recognised body of work, or, had it occurred in the context of fiction, by a narrator's self-importance. But none of these conditions applies. We all ought to know that only people who love us wish to listen to our dreams.

The best writing in the book appears in its quotations from Virginia Woolf and Susan Sontag. Their intelligence mingles with the choppier stream of Angel's consciousness. Her ready-mixed metaphor "I turned the volume down on myself; I became less" is unflatteringly followed by Sontag's evolving lines on "Love as incorporation  as immolation of the self."

But there are pleasures to be had from this book. A sumptuous picture emerges of Angel's relationship with her partner, and she shows the way love permits the ordinary to snuggle up to the sublime. After the thrills of bondage, "back at mine we drink tea with Rachel, who has made a rhubarb cake and macaroons". Unmastered is at its most absorbing when Angel tests the distinctions we think we live by: "I travel in a loop of gender." She gives a moving evocation of a sexual unity that transcends gender, which tantric masters have described for 7,000 years, and which Angel, fighting against her western academic training, has attained by force of personality. "Can I be the swan? Must I always be Leda?" is a further, full-bodied hint at a universal mode of experience, neither ancient or contemporary but perpetual. Angel treads fearlessly here on the territory of Jung's universal unconscious. 

Though Angel's reflections on gender don't ask it directly, they raise a serpentine question: given that feminism has secured a collateral liberation for men by ending the female monopoly on tears, how graciously are women conceding it? She perceives in her own pillow-talk a female coerciveness, which urges men to fulfil the stereotypes she rails against: "Is this what I desire? The king's protection?"

It is a truth universally acknowledged that a man must now be a player in the bedroom, and a psychotherapist everywhere else  yet crying still makes him unattractive. To what extent is this female squeamishness punitive? Angel imagines telling her lover: "You do not feel yourself to be enough; and that feeling makes you shrink in your eyes and mine." Questioning the motives behind her mid-coital exaltations, she realises, "sometimes I need to make you bigger".

She is also highly receptive to her experiences. Sontag's "Fucking vs being fucked. The deeper experience  more gone  is being fucked" may have more resonance with that delirious "gone" than Angel can ever summon. But she is a hard worker, and Unmastered has some impressive one-pagers. Angel captures, for example, all the fluttering significations of having a man ejaculate on her breasts  she is, at once, "Dupe. Collaborator. Victim"  before returning to her unequivocal senses: "I always liked that  the sharp gasp of wetness on the skin."  

There is little in the sensual connoisseurship and conflicted girlishness of Unmastered that the novelist Anaïs Nin didn't explore more eloquently in her six-volume diary. But Angel's cheeks are consistently pink, while Nin's are fitfully pallid: "I also hate Dutch paintings, penis-sucking, parties and cold, rainy weather," writes Nin, disconcertingly. Unmastered is a blemished but vigorous testament to a female libido undaunted by the cold shower of self-analysis, or by the bedside interjections of feminist heroines. 

Toward the end of the book, Angel describes herself at an academic conference wondering if her feminist principles really have to deny her the pleasures of submissiveness. "I want to throw off my feminism, my stitched-up fabric head," she cries. Figuratively flat, but charged with sincerity, she calls to mind that transcendental self-justification offered by Whitman: "Do I contradict myself? Very well, then I contradict myself. I am large, I contain multitudes."