LOS ANGELES - In a hilarious scene from the new series "Life's Too Short," Liam Neeson botches an improvisational exercise with writing partners Ricky Gervais and Stephen Merchant by trying to mine AIDS, stomach cancer and famine for comedy gold.

Merchant finally finds the courage to suggest to the deadly serious actor that such subjects don't lead to laughs.

Neeson points to Gervais.

"Then how does he get away with it?"

In the episode, which airs Sunday, Gervais simply shrugs. In person, he makes it clear that tackling taboos is something to which he gives a lot of thought.

"We're not trying to be outrageous for outrageous' sake. That's too easy, it's childish and pretty pointless," he said. "But you do have to go as far as you can to explore comedy. The job of a comedian isn't just to make you laugh. It's to make you think, as well. I shouldn't have to, but I think I can justify everything that I do."

Not everyone agrees. Gervais seemed harmless enough in 2003 when his BBC series "The Office" became the finest European export since Guinness.

But then Gervais began pushing buttons.

He took hits for his standup act in 2007 after he made a joke in Scotland about killing prostitutes, less than a year after several hookers were murdered there. His 2009 film "The Invention of Lying" started off as a typical romantic comedy, but took an abrupt turn when it became a platform for atheism, which didn't exactly amuse certain religious groups.

His TV series "An Idiot Abroad," which airs Saturday nights on the Science Channel, could be perceived as borderline bullying, with Gervais playing practical jokes on "friend" Karl Pilkington throughout a worldwide expedition.

And then there's his three-year run as Golden Globes host. During his stint, audiences appeared more interested in seeing which celebrities Gervais would go after than in finding out who was TV's best supporting actress. Last year, Gervais introduced Robert Downey Jr. as an actor best known "from such facilities as the Betty Ford Clinic and Los Angeles County jail." The "Iron Man" star labeled Gervais' performance as "hugely mean-spirited."

Downey probably won't be a fan of "Life's Too Short."

The series, shot as a mockumentary, follows dwarf actor Warwick Davis, who struggles as much with his giant-sized ego as he does landing a job. Gervais and Merchant, also playing warped versions of themselves, can't stand the guy. In just the first four episodes, the series addresses pedophilia, blackface and -- naturally -- little people.

One person who doesn't mind is Davis. In fact, the show was his idea.

"It's not particularly raunchy," said Davis, who has appeared in "Willow" and the Harry Potter movies. "It does push the boundaries of comedy, and that's what's exciting. That's what Ricky and Stephen do best."

Johnny gets his gun

One somewhat surprising supporter is Johnny Depp, whom Gervais teased at the Golden Globes last year. He shows up in a future episode of "Short," hiring Davis to provide insight for an upcoming production of "Rumplestiltskin." In the process, he makes Davis dance like Michael Flatley and stuffs him in a toilet.

Gervais insists he's not going for cheap laughs. There's a reason for every squirm-inducing moment, and the main one for "Short" is this: Fame can make monsters out of even the kindest people, and they'll do the most embarrassing things to remain famous, a theme he explored in an earlier HBO series, "Extras."

"I think some people confuse the target of a joke with the subject of a joke," he said. "You can have jokes about race without being racist, et cetera. Which we've always done. I think sometimes people flinch too soon. Smart people know what we're trying to do."

Gervais goes so far as to describe his comedy as "warm." Even if "The Office's" David Brent could be a five-star jerk, by the end, fans were rooting for the insecure manager to find true love. Gervais promises we'll eventually feel the same way about Davis, a "nasty little fascist who sees the light."

"I'm a considerate comedian," Gervais said. "I'm not one of those people who think comedy is your conscience taking a day off. My conscience never takes a day off."