Travel is really the experience of uncertainty and strangeness,” remarks Paul Theroux. His observation couldn’t have been more apposite, as news has just come in that the Calcutta Book Fair, where the celebrated American travel writer was to have delivered the inaugural lecture, has been cancelled. Theroux receives the news calmly. For an inveterate traveller like him it’s one more instance of the manifold uncertainties a journey brings in its wake. It just proves his point.

But Theroux’s visit to Calcutta earlier this week was not merely about lending his presence to the book fair that never was. Last year he toured India extensively, retracing the route he took for his famous trans-continental railway odyssey, The Great Railway Bazaar (1975). But somehow, Calcutta got left out of his trajectory. The trip to the city this time will make up for that omission. And the experience will perhaps be distilled into a new book to be published later this year — Ghost Train to the Eastern Star — which is a sort of a reprise of The Great Railway Bazaar 33 years on.

“So in a sense, this is a sentimental journey for me,” says Theroux, 66, who seems to be in fine fettle even though he has just checked into his hotel after having flown more than halfway across the world from Hawaii. He tells you that it is important for a writer to revisit the place he has written about. “No place can be defined by just one visit. For instance, the India that I saw 33 years ago has more or less disappeared.”

Though a critically acclaimed novelist — he has written 27 novels, many of which deal with the expatriate experience — Theroux is perhaps best known for his travel books. Whether he trundles along on a slow train across the Asia Minor or hurtles down by rail (trains hold a peculiar magic for him) all the way from Boston to Argentina, or whether he sails the Yangtze, his accounts are always sharp, always vivid, and nearly always shot through with wry, ironic humour. Sometimes he can be merciless, his pen slicing through the follies and idiosyncrasies of people and showing them up in harsh, unsparing light. But he writes of people and places as he sees them, he says. “A lot of the travel writing I had read before was about sightseeing — there was no dialogue, no humour. But I wanted to write about the human architecture, rather than about temples.”

After more than 35 years of touring the globe, travel for Theroux is more than an enterprise. It is almost a philosophy. “Travel is essentially about freedom and about discovery,” he says. “And it’s about self-discovery too — because you find out something about yourself — your patience, your intelligence, your ability to get along with other people.” He also feels that the experience of the traveller is akin to that of the writer. For both are strangers on a path to discovery — of one’s inner self and of the world without.

But travel, in the true sense of the term, is distinct from tourism, insists Theroux. Indeed, he treats tourism with a faintly disparaging air, setting the solitary traveller who’s in search of adventure and enlightenment way apart from the vacationing hordes looking for a pretty place to soak up some nature and culture. “Travel isn’t a holiday,” says Theroux. “There’s more suffering in travel, more delay, more nuisance.” He’d make a pretty bad tourist, actually, he says. “I’d rather go some place and have a harrowing, hellish time and have something to write about!”

Wanderlust came early to Theroux. Even as a little boy in Medford, Massachusetts, he used to think that the world was “somewhere else”. He became a Boy Scout at the age of 11 because he thought it would help him become self-sufficient and that would stand him in good stead when he finally left home. Did he know then that he wanted to be a writer? “Not really,” he replies. “I loved to read but I didn’t know how to become a writer, or what the logistics of writing involved.”

After graduating, Theroux joined the Peace Corps in 1963. The Vietnam War was starting then and he didn’t want to fight in that war. “Joining the Peace Corps was a way to resist the war, and resist the draft and yet do something positive,” he says. It was also his passport to strange and wondrous places.

He was sent to teach English in Malawi in central Africa. And before long, Africa coaxed the writer out of him. By 1967, Theroux had published his first novel, Waldo. He was teaching at Makerere University in Kampala, Uganda, then. That’s where he met V.S. Naipaul, with whom he was to have a three-decade-long friendship. The friendship finally ended in bitterness and acrimony, leading Theroux to write a controversial tell-all book about his relationship with his former mentor.

Sir Vidia’s Shadow (1998), a book that set a cat among the literary pigeons, is a portrait of Naipaul as a deeply flawed man — a man who can be cheap and cruel, and almost abominably rude and insulting. “I met him when he was 34 and I was 24,” recalls Theroux. “He took me seriously as a writer when I needed to be taken seriously.” So why did he do the book? “Because it is rare to read about a friendship, especially a literary friendship, that has ended,” says Theroux. “If I’d written a book about Naipaul while I was friends with him it would have been a portrait of an interesting guy. But mine is a portrait of a monster. He’s a wonderful writer, but he’s a monster!” he exclaims, laughing, but you know he isn’t joking. “A wonderful writer,” he reiterates, “but as a man — defective. He’s not all there. But that’s okay. That makes him more interesting.”

Whew. Well, no one can say Theroux tries to mince his words. Indeed, telling it like it is, or at least the way he perceives it to be, is almost a literary credo for him. Which is why his best-selling travelogues — The Great Railway Bazaar, The Old Patagonian Express, Riding the Iron Rooster and others — engaging though they are, can sometimes seem a bit too harsh on their subjects. “But I’m not an objective writer,” he protests. “My books are not geography books, they are not facts.”

Even so, how far would he go to depict what he deems to be the truth? What if that “truth” hurts people? What, for instance, does he think of comments like “bandy-legged Madrasis” or “black darting clerks” (The Great Railway Bazaar, circa 1975) today?

“Well just as places change, people change too,” says Theroux. “So I don’t think I would be given to generalisations like that now. And I do hold back if I think I am wrong. It does occur to me sometimes that I may be wrong,” he admits with a slight smile.

But on the whole, Theroux feels that political correctness is inimical to good writing. If you begin to censor yourself, he says, you become self-conscious and start filtering everything. On the other hand, if you tell the truth about a place, you could end up being prophetic, foretelling its future shape and form. For instance, Riding the Iron Rooster (1988) — a book based on his travels across China and Tibet — was, in a sense, prescient. Initially, Theroux was widely panned for his bleak view of China. “I had seen how the government was suppressing public opinion, how the police were punishing students. But the reviews said, ‘oh, he’s too negative, he’s a curmudgeon, Mr Grouchy Traveller, etc, etc’.” But then Tiananmen Square happened, a peaceful student protest was brutally crushed, and Theroux felt vindicated.

Theroux tries to write about a place as though it has never been written about before. That’s why he doesn’t read too many travel books for fear they may influence his response to a place. But he does single out Mark Twain’s Following the Equator — “very funny, very subjective” — as a book that inspired him to become a travel writer.

His ceaseless wanderings could have taken a toll on his family life after he became a full-time writer in the early Seventies. But Theroux’s first wife, with whom he had two sons, was supportive of his decision to be out and about, exploring and observing. “That’s the negative side of travel,” he says. “You feel guilty about leaving home.”

Today his home is in Hawaii, where he lives with his second wife. He raises bees there. Just a few minutes from his house lies a white sandy beach — serene, idyllic. But the wonder and the adventure clearly lie elsewhere. And Theroux, the traveller, simply goes on seeking.