The audience’s split second of shock is always palpable when it hears George Carlin say, “If there is a god, may he strike me dead.”

So far, there have been no takers. After 50 years of doing it his way, why shouldn’t he exercise fearlessness?

At 70, his scrawny frame is a metaphor for everything pared down to essentials. He travels light. No advance team of publicists, no entourage, no handlers. No post-show party at the hotel. Maybe just one person along to take care of details, his manager of 30 years, Jerry Hamza.

“We fly in the same day I perform,” Carlin says. “I get a hotel room, lie down and watch TV. Then I pick up my bag and go to the theater. At intermission, I get my papers together. After that I’m back on the plane.” Even at home, he’s not a great schmoozer, working the phones, booking the right tables. “I don’t hang out well,” he says. “I’m not interested in people who have little to say.”

Carlin has gone through his changes, from ’50s-era white-bread standup with skinny black tie to hippie-dippy weatherman, to the curmudgeonly Jeremiah we see now, raking the audience with, as he says, “strong ideas, defensible but funny. Ideas that’ll challenge your beliefs.”

He’s even had a midcareer bout with drugs, which was de rigueur for most comedians throughout the ’60s and ’70s, and which the smarter ones realized was a dead end.

But there’s a direct line between the stern figure we see onstage today and the 8-year-old kid in New York’s Morningside Heights discovering a gift for mimicry — and by 13 honing his skills over a bulky Webcor tape recorder.

“My father and mother were verbally gifted, so I have the genetic brand,” he explains. “I loved to watch Danny Kaye in the movies. I thought I’d be an actor. I’d start by being a deejay, then a comedian, then I’d get into the movies.”

On the way, he became an American classic figure in the liveliest of arts by stopping at standup. His memorable routines over the years include “My Stuff” and “People I Can Do Without.” His “Seven Dirty Words” still rattles like a steel tooth through the gears of the FCC.

His reply to the common farewell “Have a good one” — “I already have a good one; I’d like a longer one” — is among a number of ready reminders to the habitually dumb things we regularly say to each other.

Memorable lines

And a lot of his lines have remarkable staying power. After noting that the “peace dividend” produced by the end of the Cold War lasted about four minutes, he observed, “Aren’t we about due to start bombing some helpless civilian population with a marginally effective air force? I really think we oughtta be out there doing what we do best, making holes in other people’s countries.”

Sound apt right now? He said this in 1991.

Commercial success and acclaim have followed: There have been books — 1997’s “Brain Droppings” stayed on the New York Times bestseller list for 40 weeks, while Carlin took pride in the fact that 2004’s “When Will Jesus Bring the Pork Chops?” was banned by Wal-Mart.

There have been plenty of groundbreaking comedy LPs, too, with 1973’s “FM & AM,” 1992’s “Jammin’ in New York,” 2001’s “Brain Droppings” (the CD version) and 2002’s “Napalm and Silly Putty” all winning Grammys.

Meanwhile, 12 one-hour HBO standup specials aired since 1977 have yielded numerous CableAce Awards and Emmy noms.

At bottom, Carlin is highly conscious of structure and craft.

“It’s especially satisfying to be recognized as someone who works in layers,” he says. “When I was a young man starting out, I read Arthur Koestler’s ‘The Art of Creation.’ It describes a triptych, where the jester values not just jokes but their underlying ideas, and how he also has to be a poet. That’s always been important. It wasn’t until the ’90s that I realized that my voice wasn’t as much in standup as it was in writing.”

Characteristically, he makes no effort to cozy up to his audience. His shots at religious fanaticism and superpatriotism, both expressions of powerful intolerance, come from an increasingly brave, increasingly lonely sniper position.

Consider this line from his act: “Religion has actually convinced people that there is an invisible man living in the sky, and he has a special list of 10 things he does not want you to do, and if you do any of these things he will send you to a place full of fire and smoke and pain and torture forever … but he loves you and he needs money.”

He doesn’t talk about dating, sexual confusion, his personal problems or his ethnicity — none of the usual standup hand-me-down stuff.

Instead, his appeal is to his audience’s intelligence and moral agency. He clears the air.

In answer to psychobabble and the bureaucratese that’s polluted much of our conversation, he warns that you will not hear him say, “hopefully, power lunch, lifestyle, dialogue, scenario, ballpark figure … We will definitely not interface. I will not share anything with you. If you don’t tell me your significant other is having an identity crisis, I won’t say I’m going through a growth experience.”

Carlin doesn’t do the club scene anymore. “I don’t play colleges either,” he says “The audiences are too homogeneous; the material goes over their heads.”

When he’s not performing concert venues he’s booked into Las Vegas’ Orleans hotel.

His material is still informed by the the upheavel of the ’60s. He remains indebted to a period when, as he says, “the cultural revolution included a sexual revolution; there was a shift in how we viewed authority; language broadened. We (comedians) went along for the ride.”

And when that ride landed him in movies, his ultimate boyhood destination, he discovered that he hated it.

“It’s a waste of time,” says Carlin, who dabbled in supporting feature roles, such as guruish Rufus in “Bill and Ted’s Excellent Adventure,” and even had his own Fox sitcom in 1994 (the short-lived “George Carlin Show”). “It’s not gratifying. Someone else is telling you what to do. I’d like to have been an actor, but you can’t make it a sideline. I’m a writer. I like putting my work out onstage.”

Asked about the changes he’s witnessed over the years, he replies: “My experience is different from other comedians. I don’t find myself up against the average audience. I’m not an entertainer. The artist has to dig inside himself and take the audience on a journey. Comedy hasn’t changed. It’s the culture that’s changed.”

And to a chronic outsider, kicked out of high school and the Air Force for his rebellious views, the cultural change is appalling. Instead of basking in rosy career retrospectives before beaming black-tie throngs, his loner take on the contemporary scene is so far beyond indignation that it qualifies for a Kubler-Ross stage of death — acceptance.

“I enjoy watching the culture destroy itself,” he says. “It’s squandered its beautiful gift. Once you’ve given it all up to God and Mammon, it’s time to circle the drain, as they say in the hospital. You can hold lotteries, vote, sign petitions, step up at stockholder meetings, it makes no difference. You can’t fix it. Censorship from the right, arrogant paternalism from the left, big oil, big agriculture, big finance, big pharmaceuticals … The promises are either false or undeliverable. No one questions authority. I love getting out there beyond Pluto’s orbit and looking down on the Earth.

“I’m beyond mourning.”