In his quest to produce the perfect novel, Jonathan Franzen spent four years writing in the dark, wearing earplugs and a blindfold. Judging by the critics' response to The Corrections, it paid off

In 1996, Jonathan Franzen made a reckless public vow. He did it in the pages of the American magazine Harper's, in a bitter, eloquent, intensely personal essay entitled 'Perchance to Dream: In an Age of Images, a Reason to Write Novels'. The big socially engaged novel was dead, he declared, killed off by TV.

Serious postmodern novelists like Thomas Pynchon and Don DeLillo were doomed to irrelevance. Contemporary readers wanted entertainment, not news, engaging stories, not ideology. Franzen did more than just diagnose the problem. He implied that he could solve it. He made a promise to deliver a book that had it all, a novel that was intimate, socially engaged and compelling.

How he would do so wasn't exactly clear. Still, the essay was a dashing piece of audacity on the part of an obscure young writer with two novels to his name. With its provocative argument, authoritative tone and chummy allusions to members of the American fiction establishment (at one point, he quoted from a personal letter from DeLillo), it presented Franzen as a major league literary player from whom one could expect great things.

'I raised the bar,' he concedes now. 'And boy, it was really high stress.'

We're at a restaurant in Greenwich Village, eating crabcakes. He tells me how, having written the Harper's essay, he locked himself away in his spartan studio on 125th Street in East Harlem to write. Some days, in order to keep his mind 'free of all clichés', he wrote in the dark, with the blinds drawn and the lights off. And he wore earplugs, earmuffs and a blindfold. 'You can always find the 'home' keys on your computer,' he says in an embarrassed whisper. 'They have little raised bumps.'

He lived like this for four years. 'I don't think you know how weird I am,' he says nervously.

The Corrections finally hit American bookshops on 5 September, propelled by extraordinary hype and expectation. It became an immediate, unequivocal success. Time magazine deemed it 'one of the great books of the year', and the New York Times Sunday Book Review found it 'marvellous - everything we want in a novel'. The movie rights were snapped up before the book came out (by producer Scott Rudin, a specialist in literary adaptations including Wonder Boys and Angela's Ashes .)

Perhaps even more gratifyingly for Franzen, Americans are reading it. Despite the devastating terrorist attacks on 11 September and the state of uncertainty into which they have plunged the arts, The Corrections has climbed steadily up the bestseller lists.

It certainly looks like vindication. But success has not entirely agreed with Franzen. When Oprah Winfrey selected The Corrections for her book club last month - a decision virtually guaranteeing millions of dollars in additional sales - he publicly questioned her judgment, suggesting to more than one interviewer that his novel's 'high-art' literary qualities made it a dubious choice for a programme normally associated with middlebrow fiction. His remarks started a national scandal. Winfrey disinvited Franzen from appearing on her show, and the literary community rallied to her defence, calling Franzen arrogant and ungrateful. 'That pompous prick' was how one powerful agent referred to him.

Franzen is now busy trying to explain his way out of the gaffe, telling the New York Times last week: 'Mistake, mistake, mistake to use the word "high". Both Oprah and I want the same thing and believe the same thing, that the distinction between high and low is meaningless.'

Whatever his true feelings on the high- versus low-brow debate (and one suspects he was not being entirely honest with the New York Times), Franzen's book is much clearer on this point. The Corrections is as clever as the brainy postmodernists Franzen admires but infinitely more accessible. Like DeLillo, he dazzles the reader with trenchant riffs on contemporary life - everything from mood-enhancing pharmaceuticals to bisexuality to cruise-ship culture. But Franzen embeds them in the lives of affecting human characters.

It sounds suspiciously simple. But this, it turns out, is Franzen's big idea: characters are what the contemporary novel lacks - and what can save it from oblivion. And come to think of it, he has a case. In stuffing their books with formal gimmicks and oracular pronouncements, male postmodernists turned the social novel into an act of intellectual machismo and long ago showed characters the door. The job of creating memorable characters became women's work, the forte of writers such as Anne Tyler and Annie Proulx.

Franzen aims to bring these traditions together. Like DeLillo, he wants to take on the world, but rather than populate his book with an anonymous horde, he gambles his ambition on a single family. Franzen's Lambert family is in a state of freefall ('Correction' is the term employed by Wall Street to describe a sudden collapse in, well, in values). There is Enid Lambert, the obsessive Midwestern wife, fixated on the impending family Christmas; there is Al, her exasperating husband, battling Parkinson's-induced dementia. Then there are the three mixed-up Lambert children scattered along the East Coast: Gary, an unhappy suburban banker; Chip, a raffish failed screenwriter; and finally, Denise, a sexually confused gourmet chef. The question preoccupying Enid is, can she induce her children to recreate the family for the holiday period and allow her husband to end his days in an ambience of dignity and worth?

The family's collapse is paralleled by the decline in American society. The Lamberts grew up with Al working for an old-fashioned railway company, but this has now passed into the hands of asset-strippers and speculators. The children, too, are initially defined by their position in the new economy and, like their mother, by the way they deal with inner turmoil. Enid, for example, finds euphoric escape in Aslan, a 'personality optimiser' prescribed by a manically cheerful doctor on a cruise ship. But Gary goes it alone, determined to avoid drugs or therapy.

If The Corrections delicately probes the ambiguous blessings of a society dedicated to pain-free living and chemical quick-fixes, then Franzen in person is more explicit. 'Alleviating suffering is very good, but it comes at the cost of what I would call a narrative understanding of one's life,' he says. 'You don't need to have a story anymore. Your story becomes: the chemicals in my brain were bad; I fixed those chemicals. From a humanitarian standpoint, that's great, but it makes for a less interesting world.'

Franzen has almost wilfully made sure that his own personal world has been 'interesting' in this sense ever since he began writing. As newly weds in the mid-1980s, he and his wife, Valerie Cornell, from whom he is now divorced, lived a strange, hermetically sealed life in a tiny flat near Harvard University. Separated by only 20 feet, they wrote eight hours each day and then, after a dinner break, read for five more. Franzen supported them both with a weekend job as a research assistant tracking earthquakes for the university's geology department. He and Valerie ate out precisely once a year: on their wedding anniversary.

The novelist David Foster Wallace, who met the couple around this time, remarked that they were living with 'faces pressed against the inside of the bell jar'. At the time, Franzen says with a laugh, 'I didn't know what he meant.' Valerie did. 'She said that if a social worker had found us, we would have been turned in for self-abuse.'

Franzen's writerly life began shortly after he and Cornell graduated from Swarthmore in 1981. At a gathering of the campus literary magazine, she dazzled him with a casually brilliant interpretation of a particularly inscrutable poem. 'She's a really, really good reader,' he says. In 1982, they decided to marry and devote themselves to writing.

A decade later, Franzen was miserable. His marriage was unravelling, his father was dying of Alzheimer's and, though he had published two accomplished novels, he was broke and essentially unknown. His first book, The Twenty-Seventh City, appeared in 1988, when he was 29. An intricate thriller about urban planning set in St Louis (Franzen's hometown), it made a splash, but some critics were confused about its intentions. Strong Motion, published in 1992, featured earthquakes, corporate conspiracy and family conflict. It did worse than the first book, a fact Franzen defensively chalks up to 'a not immediately likable main character, a bad jacket and second-novel backlash'.

By the time The Twenty-Seventh City appeared, he and Cornell had left Harvard and embarked on an itinerant existence occupying rented apartments and borrowed houses, together and alone, for a few weeks or months at a stretch all over the east coast of America and in Italy. The constant relocating, he says now, was part of a futile bid to save the marriage: 'We kept trying to solve non-geographical problems geographically.' It didn't help that Franzen's manuscripts had found publishers while his wife's more experimental novel had not. 'When the rewards of our jointly held ambition began to accrue to me,' he says, 'it was very hard.'

When they separated in 1994, Franzen was supposed to be at work on his third book. He produced an 80-page lament about his feelings of cultural irrelevance instead. That essay, titled 'My Obsolescence', was never published. But Franzen mined its dark themes for his Harper's essay. In late 1996, he moved to his current address, a modest third-floor flat on Manhattan's Upper East Side, and sold The Corrections to Farrar, Straus & Giroux on the basis of 200 pages. Yet when his 1997 deadline arrived, he had thrown all but 20 of those pages away.

Unlike other novelists wedded to reportage - say, Tom Wolfe - Franzen did not haunt Bronx ghettos or Atlanta social clubs in search of material. His struggle to complete his novel took place mostly in the solitude of the studio he began renting in 1997, a nook inside a sculptor friend's Harlem loft. When asked how he was able to write convincingly about Parkinson's or the streets of Vilnius (to which Chip flees on a rash impulse), he shrugs. 'I've never been to Lithuania,' he says. 'And my agent's brother is a neurologist; we went to dinner.'

Nor did he raid his circle of acquaintances for titillating personality traits. If characters are Franzen's great distinction as a writer, that's because he has dedicated the bulk of his strenuous imaginings to making them up. For The Corrections, he literally spent years developing characters before he tackled the plot.

As for his title, Franzen originally conceived a central prison theme for The Corrections, but as the decade crept on, and the stock market boomed and busted, it took on an uncanny new resonance. 'I'd been predicting this for years,' he harrumphs about the recent downturn.

Franzen had an easier time with his title than with his prose. 'I was in such a harmful pattern,' he recalls. 'In a way, it would begin on a Friday, when I would realise what I'd been working on all week was bad. I would polish it all day to bring up the gloss, until by four in the afternoon I'd have to admit it was bad. Between five and six, I'd get drunk on vodka - shot glasses. Then have dinner, much too late, consumed with a sick sense of failure. I hated myself the entire time,' he says.

One night, he got scared. He asked a female friend who had come to see him to leave in the middle of a downpour. Soon after, he made an appointment with a doctor who could prescribe antidepressants. In the end, unsure about how a substance like Prozac would affect a writer's brain, he decided not to go.

'I feel my sensitivity is my business,' he explains. It could be Gary Lambert talking. 'One of the things a really good novel can do is give you a sense of recognition about the strange private life you are leading,' he tells me. 'Our life is not just our parents dying or being angry about what we read in the paper. It's about questions: should I take Prozac or not? What is my personality then? What is my self then? In our technologically changed world, it seems to me that a book not only has to do justice to those private stories, which are really old-fashioned stories of loss or love or longing or anxiety, but also take into account that those stories are now unfolding in a regime that seems to be resisting the narrative account and replacing it with material accounts: you can buy or drug your way out of unhappiness. For people who are struggling with 'What does my life mean?' and 'How should I live it?' the best novel you can write is the one that's going to take into account both.'

It's hard to think of suffering as research. No doubt Franzen wouldn't see his own this way. Misery befell him; he didn't seek it out. And as his despair receded, his work began to flow; he wrote most of his book in 2000. Besides, as cultural myths go, the one of the suffering artist has been way overplayed. Sylvia Plath's depression, Jackson Pollock's drinking: was their art really fuelled by their afflictions?

Still, it is tempting in some ways to believe that Franzen's suffering was a condition for his success, that to make us believe in his characters' struggles, he needed to endure his own. And hardship, it seems, is something Franzen seems almost too willing to bear. He certainly wears it easier than success. For an instant, he stares me straight in the eye. 'Among novelists I know, no one is more ambitious than I am.'

· To order a copy of The Corrections by Jonathan Franzen for £15.99 plus p&p (rrp £17.99), call the Observer Books Service on 0870 066 7989. Published by Fourth Estate on 2 January 2002