Jeanette Winterson's grand gestures

Is it a book, or an art-object? It is small, squarish, quirkily laid out (ah the rogueries of "design"), with a bit of dotcom jokiness in the title and a naked woman in decadent Beardsley yellow with a Pre-Raphaelite mope on the cover. And the review copy comes with a CD, from which we learn absolutely nothing. So, a bit of the old and something of the new. "Twenty-first century fiction that uses past, present and future as shifting dimensions of a multiple reality," says the blurb.

It is the world of historical changelings, androgyny and the rest, with incursions into everyday London, Paris, Capri. There is nothing wrong with the genre and Winterson at her best remains a fine writer. The trouble is that, like so much of our stunningly unique 21st century culture, it's all been done: Winterson's Duchamp and Tristan Tzara are people like Virginia Woolf and Marguerite Yourcenar, she of the brilliant Oeuvre au Noir. All that's left to bring to the party are her gift for language, unabashed lesbianism and a couple of cybernetic tricks.

And, of course, science. Once it was relativity that haunted a generation of writers, now it is genetics or astrophysics (which Winterson has "done" in Gut Symmetries). In this book it is cybernetics that inspire Winterson's plot and some of her better ruminations. ("The one life we think we know is only the window that is open on the screen.") To begin with the idea appears promising: that an emailer will write you into a story from which you may emerge as someone else. So the book can range from Boccaccio-like episodes to modern Spitalfields. Multiple realities and morphing characters can be a fruitful release from conventional narrative, but they also release you from discipline, leaving the author prey to whimsicality and stray associations. In The. PowerBook they allow Winterson, a stern stylist, to combine a fine economy of form with an irritating preciosity of sentiment.

Her first and best book, Oranges Are Not The Only Fruit, told of her break with her evangelical upbringing. Release from the nunnery can sometimes prove to be provisional, and now she has immured herself in another cloister. Increasingly she sounds like une exalt?e, an evangelical preacher, a Bible puncher for Art and sapphic love. The fairy story element in The. PowerBook allows for mystic touches, and its more contemporary pages for sermonising: "We walked to the dirty hissing train and found you a seat opposite a Walkman wearer and a woman reading Hello! magazine. This is the emotional and cultural life of the nation. No wonder grand gestures fall flat. How can you say yes when everything around you is saying no?" Sadly this yea-saying too often turns into perfumed whiffle like, "Why then fear death, which cannot dissolve me more than I dissolve in you, this day, this night, always."

Where is the hard, truthful, unpretentious prose of the early Winterson, a tough, earthbound yet enormously suggestive voice? Not that the promise of that work is entirely gone. Often the distinctive language is still there, yet it signifies less and less, like superb actors in an indifferent play. Where there are still glimpses, as in the story called Spitalfields, they fade swiftly into a strained aestheticism, or into the higher quirkiness. Parts of it read like translations from the French that don't come off, passages which for some reason I associate with Jeanne Moreau's fish-like mouth droning on about life and lurve. Sentences like, "Love is a door in a blank wall" invite unavoidable parodic responses (no it's not - "Love is/Without pyjamas"). Once or twice wouldn't matter, but there is so much of it: "It began with a promise. While I am living I shall rescue you."... "Her heart was like a bird that flew away and returned with stories in its beak." Who or what, one wonders, has been the enemy of the promise shown by the most vital woman writer of her period? In her case it cannot be Connolly's pram in the hallway. The enemy of Winterson's promise is Art. She is not the only sufferer: as Whistler once said in his infamously arty Ten O'Clock Lecture, "Art is upon the town." Indeed it is, and the epidemic is a killer.

Whether it be the clever-clever graphics on News-night, the curatorial twaddle at Tate Modern, or the cultural micturation that gushes endlessly from ministers, we are living through an infestation of artwork, art-talk, artiness of all descriptions. If only she could abjure Art the way she abjured religion and write less self-consciously, the true artist in Winterson would re-emerge from what is beginning to seem like indefinite hibernation. English writing is not so rich in talent that it can afford to watch hers evaporate in a cloud of sickly incense.