"I have decided to take whatever my disease can throw at me," wrote Christoper Hitchens in his most recent essay. But today, after 18 months, his duel with cancer ended. He was 62 years old. The world has lost one of its most outstanding and prolific journalists and a wonderful polemicist, orator and bon vivant. Hitchens could write brilliantly about an extraordinarily wide range of subjects and people: the death penalty, religion, Leon Trotsky, Evelyn Waugh, the British monarchy, the Israeli-Palestinian conflict, George Orwell, Saul Bellow, the Elgin Marbles, North Korea, the Balkans, Henry Kissinger, Thomas Paine and Philip Larkin.

In recent months we had sad cause to add cancer to that list. The series of essays Hitchens wrote for Vanity Fair about his illness stands as the finest writing on the subject since John Diamond's C: Because Cowards Get Cancer Too. Without a hint of self-pity or sentimentality, Hitchens confronted his fate with pure reason and logic. "To the dumb question, 'Why me?'", he wrote, "the cosmos barely bothers to return the reply: 'Why not?' " Nor did his humour desert him. To a Christian who insisted that God had given him "throat" cancer in order to punish the "one part of his body he used for blasphemy", he replied: "My so-far uncancerous throat . . . is not at all the only organ with which I have blasphemed." And to those who insultingly suggested that he should embrace religion, Hitchens's flawless riposte was: "Suppose there were groups of secularists at hospitals who went round the terminally ill and urged them to adopt atheism: 'Don't be a mug all your life. Make your last days the best ones.' People might suppose this was in poor taste."

I interviewed Hitchens for the New Statesman in May 2010 during the UK leg of his Hitch-22 tour. Over several glasses of Pinot Noir and Johnnie Walker Black Label, we discussed, among other things, religion, neoconservatism ("I'm not a conservative of any kind"), his time at the NS, Zimbabwe (his biggest regret was that he hadn't been tougher on Mugabe in the 1980s) and the euro. Hitch was on form that day, calmly eviscerating the likes of David Cameron ("He seems content-free to me. Never had a job, except in PR, and it shows. People ask, 'What do you think of him?' and my answer is: 'He doesn't make me think' ") and Sarah Palin ("I think she's a completely straightforward cynic and opportunist and I think she's cashing out . . . She's made a fortune and she'll make another. But she's not actually going to do the hard work of trying to lead or build a movement"). Two days later he returned to the US. A month later he was diagnosed with cancer. He never returned to the country of his birth.

It was the United States, where Hitchens lived for more than 30 years, that he came to call home. By the end of the 1970s, he had tired of Britain ("Weimar without the sex" was his verdict on the Callaghan era) and longed for the bigger stage of America, moving first to New York and later to Washington, DC. He struggled at first, eking out a living writing a biweekly column for the Nation magazine and relying on the kindness of friends such as the radical journalist Andrew Cockburn. But the move paid off when he landed a column for Vanity Fair in 1992, greatly increasing his income and his readership. It was also there that he met his adoring second wife, Carol Blue, who once remarked of him: "I was just glad such a person existed in the world." He is survived by Blue, their daughter, Antonia, and two children from his previous marriage to Eleni Meleagrou, Alexander and Sophia.

"I believe in America. America has made my fortune," declares Bonasera in the opening line of The Godfather. Hitchens's allegiance to the US (he became a citizen in 2007) had more to do with its secular constitution and its commitment to free expression but America did make his fortune. By the end of his life, with regular slots in Vanity Fair, the Atlantic and Slate, several bestselling books and a lucrative place on the lecture circuit, Hitchens was earning nearly $1m a year.

His extraordinary output – 12 books, five collections of essays – was suggestive of a solitary, bookish man, rather than a compulsively social hedonist. In resolving this apparent paradox, Hitchens was aided by two attributes in particular: his prodigious memory (as Ian McEwan once remarked: "It all seems instantly, neurologically available: everything he's ever read, everyone he's ever met, every story he's ever heard") and his ability to write at a speed that most people talk. The late, great Anthony Howard, who as New Statesman editor hired Hitchens in 1973, told me last year: "He was a very quick writer . . . Hitch could produce a front-page leader, which would take me a couple of hours, in half an hour."

In his final interview, with Richard Dawkins (published in the current issue of the NS), Hitchens reflected, with touching modesty, on his status as an essayist. After Dawkins told him that he could think of no one since Aldous Huxley who was so well read, he replied:

It may strike some people as being broad but it's possibly at the cost of being a bit shallow. I became a journalist because one didn't have to specialise. I remember once going to an evening with Umberto Eco talking to Susan Sontag and the definition of the word "polymath" came up. Eco said it was his ambition to be a polymath; Sontag challenged him and said the definition of a polymath is someone who's interested in everything and nothing else. I was encouraged in my training to read widely – to flit and sip, as Bertie [Wooster] puts it – and I think I've got good memory retention. I retain what's interesting to me, but I don't have a lot of strategic depth. A lot of reviewers have said, to the point of embarrassing me, that I'm in the class of Edmund Wilson or even George Orwell. It really does remind me that I'm not. But it's something to at least have had the comparison made – it's better than I expected when I started.

Hitchens's modesty was unwarranted. In this age of high specialisation, we will not see his like again.

It was God Is Not Great, his anti-theist polemic, that sent him supernova. While Dawkins's atheism is rooted in science, Hitchens's was rooted in morality. He was repelled by the notion that people do good only because they fear punishment and hope for reward. The question he often posed about believers was: "Why do they wish this was true?" Heaven, for Hitchens, was a place of "endless praise and adoration, limitless abnegation and abjection of self; a celestial North Korea".

It is Hitch the controversialist that many will remember. The man who said of Jerry Falwell, "If you gave Falwell an enema he could be buried in a matchbox," and of Ronald Reagan: "Reagan is doing to the country what he can no longer do to his wife." But as John Gray wrote in his NS review of Hitchens's fifth and final collection of essays, Arguably, he was no mere provocateur or contrarian. Throughout his career, Hitchens retained a commitment to the Enlightenment values of reason, secularism and pluralism. His targets – Mother Teresa, Bill Clinton, Henry Kissinger, God – were chosen not at random, but rather because they had offended one or more of these principles.

Over the past decade, many on the left came to regard Hitchens not as a friend but as an enemy. Tariq Ali, a fellow soixante-huitard, wrote: "On 11 September 2001, a small group of terrorists crashed the planes they had hijacked into the Twin Towers of New York. Among the casualties, although unreported that week, was a middle-aged Nation columnist called Christopher Hitchens. He was never seen again . . . The vile replica currently on offer is a double." And yet, contrary to reports, Hitchens did not perform a crude midlife swerve from left to right (also known as doing a "Paul Johnson"). Unlike Johnson, a former New Statesman editor who became a reactionary conservative ("Pinochet remains a hero to me," he wrote in 2007), Hitchens did not give up everything he believed in. He maintained, for instance, that the US invasion of Vietnam was a war crime, that Kissinger belonged behind bars (see his 2001 book The Trial of Henry Kissinger for a full account of the former US secretary of state's "one-man rolling crime wave") and that the Israeli occupation of Palestine was a moral and political scandal.

His support for the "war on terror" was premised not on conservative notions but on liberal principles. As he wrote in a column for the Nation published on 20 September 2001, "What they [the 9/11 attackers] abominate about 'the west', to put it in a phrase, is not what western liberals don't like and can't defend about their own system, but what they do like about it and must defend: its emancipated women, its scientific inquiry, its separation of religion from the state."

He was wrong, badly wrong about Iraq, but for the best of reasons. His support for the invasion arose out of a long-standing solidarity with the country's Kurds (see his long, 1992 piece for National Geographic, "The Struggle of the Kurds", collected in Love, Poverty and War) and his belief that even war was preferable to the survival of Saddam Hussein's totalitarian regime ("a concentration camp above ground and a mass grave beneath it"). It was not an attempt to ingratiate himself with the neoconservatives, whom Hitchens had fought and continued to fight with on issues from gay rights to the death penalty to Israel. But he was too casual in dismissing the civilian casualties (estimated at anything between 100,000 and a million) that resulted directly or indirectly from the invasion of the Iraq and, as he later conceded, too optimistic about the Bush administration's ability to stabilise the country. In his boisterous advocacy of the war there was more than a hint of the Marxist belief in the necessity of violence in order for history to progress. As Lenin once grimly phrased it: "You can't make an omelette without breaking eggs."

Yet those who stopped reading Hitchens after 11 September 2001 are all the poorer for it. They have not read his haunting account of the US's deadly legacy in Vietnam: "Some of the victims of Agent Orange haven't even been born yet, and if that reflection doesn't shake you, then my words have been feeble and not even the photographs will do." Or his unrivalled indictment of capital punishment: "Once you institute the penalty, the bureaucratic machinery of death develops its own logic, and the system can be relied on to spare the beast-man, say, on a technicality of insanity, while executing the hapless Texan indigent who wasn't able to find a conscientious attorney." Or his unique denunciation of waterboarding: "I apply the Abraham Lincoln test for moral casuistry: 'If slavery is not wrong, nothing is wrong.' Well, then, if waterboarding does not constitute torture, then there is no such thing as torture."

The tragedy of Hitchens's illness was that it came at a time when he was enjoying a larger audience than ever. Of his tight circle of friends – Martin Amis, James Fenton, Ian McEwan, Salman Rushdie – he was the last to gain international renown, yet he is now read more widely than any of them.

In his later years, Hitchens was fond of quoting his late mother's assertion that "The one unforgivable sin is to be boring". Today, as I realise I will never hear that resonant baritone again, that Hitchens's mighty pen is still, I feel certain in saying that the world has become a more boring place.