Oscar nominee Michael Moore made history when the Writers Guild of America honoured him with the Best Original Screenplay Award.

Michael Moore says he knows why many leftist writers and filmmakers fail: they have no sense of humour.

Humour, he declared at last year's Toronto International Film Festival -- where his documentary, Bowling For Columbine, was a major attraction -- is often the best tool for examining society.

Moore, who can be a dietician's bane, appears in his film turning up at a bank that gives away free rifles with each new account, springs a surprise visit on yesteryear movie star Charlton Heston, who was then president of the National Rifle Association, and meets with a teen bombmaker who was the second on a list of terrorist suspects and complaints because he wasn't on the top.

Moore, famed for his populist attacks on corporate greed, sprang into the limelight with his first film Roger & Me over a decade ago.

He has proved his point about humour more than once in the last 12 months. His book Stupid White Men... Other Sorry Excuses For The State Of The Nation, a blistering and funny attack on the establishment that includes a Democrat, William Jefferson Clinton, and a Republican, George W Bush, has remained on the national bestseller list for over a year. From time to time, as it did last week, it has shot to the very top of The New York Times' bestseller list.

Bowling for Columbine, a study of America's paranoia and propensity for violence that has been nominated for an Oscar, is the highest grossing documentary in America. Apart from the $19 million it earned in the US, the film received one of the longest standing ovations at the Cannes International Film Festival (many believe it was at least 20 minutes), and grossed about $15 million abroad. If Bowling… gets the Oscar, the $4 million movie could gross $10 million more.

Some reviewers have complained the film is not balanced and blames white people too much while ignoring the black genocide in Rwanda. But most newspapers and magazines have hailed it.

A gun owner, Moore was once an NRA member, he confesses. He does not believe it is America's love for guns that leads to violence. Canadians too are gun-crazy but the violence there is minimal compared to the annual number of murders in the US.

Americans, Moore argues, have been courting violence from the dawn of American history four centuries ago. Much of America was occupied as a result of wars and deceptive practices. The American Civil War is one of the bloodiest in history and the battles between labour and capital took away hundreds of poor lives and ruined thousands.

Why does Moore use the Columbine High School massacre in Littleton, Colorado, where teens Eric Harris and Dylan Klebold slaughtered 13 of their schoolmates and injured dozens in 20 minutes? For one, he says mass violence in many American minds is often associated with inner cities and involves minorities.

But here, in the seemingly pristine neighbourhood of Colorado, the teens, who did not come from the kind of fractured families many blacks live with, shocked the nation by their action. Before the bloodbath, they went bowling.

Moore made history recently when he won the Best Original Screenplay Award, marking the first time a documentary feature has been so honoured by the Writers' Guild of America.

Moore edged out Joel Zwick's My Big Fat Greek Wedding, Todd Haynes' Far From Heaven, Martin Scorsese's Gangs Of New York and Denzel Washington's Antwone Fisher to win the award.

The competition at the Oscars for Moore's film is far less fierce. The nominees are Gail Dolgin and Vincent Franko (Daughter From Danang), Malcolm Clarke and Stuart Sender (Prisoner Of Paradise), Jeffrey Blitz and Sean Welch (Spellbound) and Jacques Perrin (Winged Migration).