Everyone knows that the word for Thomas Pynchon is 'reclusive': won't be interviewed, won't have his photograph taken, won't talk about his novels. But now, as he turns 60, there are signs that the writer is losing his devotion to secrecy.le
American novelist Thomas Pynchon marks his 60th birthday tomorrow, a week after publishing a 773-page novel acclaimed as a masterpiece by American reviewers "reimaging" the 18th-century surveyors who mapped the Mason-Dixon line. How he plans to celebrate this double climacteric is unknown; what you can be certain of is that there will be no readings at literary festivals, no lifetime award ceremonies, no birthday snaps in the garden or grillings by The South Bank Show. He has never given an interview or a reading, and hasn't agreed to a photo since high school. In the words of William Gibson, Pynchon disciple and cyberpunk pioneer, he "makes JD Salinger look like Boy George".

Usually mistakenly dubbed "reclusive", Pynchon in fact appears to lead a normal social life: British literati who have met him talk of an engaging lunch companion, discoursing amusingly on topics ranging from soft drugs to the oeuvre of Ellen Barkin, and eccentric only in his horror of publicity.

To the standard question, "why doesn't he do interviews?", the obvious counter is "why should he?". Knowledge of any author's life has an inevitably banalising effect, inviting the reader to gloss the work as autobiography. Looking at photos, learning where authors live, hearing their voices, munching their soundbite explanations, are all ways in which we simplify texts, subjecting them to what the young Pynchon called "entropy". If there is no financial incentive to conform, refusing to play the fame game is rational, not pathological.

After all, Pynchon is far from being the sole American writer to shun the hype process. Harper Lee (To Kill A Mockingbird) has remained silent and invisible since the late 1950s, Salinger since the early 1960s. Cormac McCarthy, author of the Tex Mex Border Trilogy, has granted a single brief, wary interview, encouragingly saying: "Of all the subjects I'm interested in talking about, writing is way, way down the list."

Likewise Don DeLillo, who (after first handing his pursuer a card reading "I don't want to talk about it") has succumbed only to a writer from an academic journal who tracked him down in Greece. He attributed his diffidence to the necessity of preserving fiction's "mystery", averring that a writer is "diminished by an audience".

This splendidly Modernist formulation is a reminder that writers were resisting demystification long before today's commodification of the author through marketing. Suspicion of publicity goes back to at least the 1880s, when Henry James began writing tales of rapacious journalists and publishers. For the critic Allon White, the obscurity of Modernism was a defensive response to the emergence of the mass media. So was the Modernist generation's preference for living abroad, what James Joyce saw as part of a strategy of "silence, exile and cunning".

It can hardly be irrelevant in Pynchon's case that, just as his debut novel V. was nearing completion in 1961-62, Time and Newsweek were sending packs of reporters to hunt Salinger down in New Hampshire, exactly as if he were a criminal on the run. Small wonder, then, that the star Cornell student who wrote a candid, chatty self-portrait in 1959 for a scholarship application had by 1963 become an interview refusenik and skilled fugitive, evading a Time photographer who traced him to a Mexican hotel by telling him that Tom Pynchon would be back at 5 o'clock and checking out at once.

For Pynchon, unlike Salinger, politics provides further grounds for choosing silence, cunning and a form of internal exile. The first three novels are linked by an atmosphere of pre-apocalyptic paranoia and the theme of conspiracy, involving a mysterious, shape-changing female spy in V. (1963), a plot to circumvent and subvert the US Mail in The Crying Of Lot 49 (1966), and the V2 rocket in Gravity's Rainbow (1973). A "We-System", linking the repressed and marginalised, is needed to oppose the "They- System" of government and the military-industrial complex. In Gravity's Rainbow, where the German "Zone" of early 1945 becomes a metaphor for Nixon-era America, the good guys are thinly-disguised members of the Sixties counterculture. The author's self-imaging avatars in the novel are conspirators, dissidents, enemies of the state.

Five US presidents later, the ideological synthesis of Gravity's Rainbow - combining anarchist politics, 'Luddite' anti-industrialism and precocious eco-militancy - remains unaltered, judging by Pynchon's occasional essays and reviews. It's no accident that Vineland, published after a long silence in 1990, self-mockingly centres on ageing unreconstructed hippy Zoyd Wheeler, still crazy after all these years.

But not quite so crazy. Mason & Dixon allows us finally to assess how Pynchon's fiction has shifted since his 17-year time-out, and the most obvious change is the dwindling level of paranoia. The protagonists of the early novels pursue mad and maddening quests, whereas Wheeler simply wants to find his ex-wife, and Mason and Dixon are employees, hired in the 1760s to plot the boundary between Maryland and Pennsylvania. Just when a distinctively Pynchonesque paranoia (involving the paranormal as well as politics) permeates popular culture, led by cyberpunk fiction and The X-Files, it has leaked out of his own work.

Whether this shift is primarily ascribable to the end of the Cold War or to personal factors (Mason & Dixon is dedicated to Melanie Jackson, his wife and agent, and their son), it coincides with a discernible relaxation of paranoia about getting traced. Maybe the notion of the radical writer as fugitive came to seem bogus; maybe penning a message of support for Salman Rushdie (who reminded authors, Pynchon wrote, of "our duty as heretics") brought home that imaging an American writer as a hunted subversive is merely a metaphor.

At any rate, the pursuit of secrecy has now lost its extremist intensity. If you're anxious to keep your identity and whereabouts secret at any price, you don't live with your agent (whose office address is necessarily in the phone book) in Manhattan. Nor do you hang out with - and write liner notes for - the New York indie band Lotion, after seeing their first CD on the desk of a bank clerk who turned out to be a band member's mother.

Secrecy inevitably generates curiosity, and Pynchon aficionados eagerly pool information, most of it now online. Via the ironically styled Thomas Pynchon Home Page (www.pomona.edu/pynchon), you can run down hard-to-access bits of Pynchoniana, discover which rock artists have drawn on his writings (Laurie Anderson, Warren Zevon, Soft Machine and, allegedly, Nirvana), and follow the debate on whether the letters of Wanda Tinasky, ostensibly sent to a north Californian paper in the late 1980s by a Russian emigre bag lady, are authentic canonical texts or apocrypha.

That Pynchon himself never clicks in seems highly unlikely, given his eclectic greed for information. And the Internet is in theory the perfect Pynchon "We-System", a spontaneous anarchist flowering outside the control of state or capital. No fan could miss the affinity with the clandestine WASTE postal network of The Crying of Lot 49, for those preferring to evade public, censored channels.

But it was the very communications network he unwittingly prophesied - or conjured into being, as hard-line cultists would maintain - that ultimately destroyed his invisibility. Six months ago, exploiting "an openly accessible online service that uses a cross-referencing of credit card and telephone numbers", New York magazine located Pynchon "in about 10 minutes", and photographed him - tall, grey-haired, holding his son's hand - from behind in the street.

As the weekly neither published the address nor photographed his face, however, Pynchon is probably untwitchy enough by now to appreciate the irony of owing his exposure to the Internet. He is perhaps even glad that after 34 years, the game - the game of not playing the game - is finally up n