The atheist movement, if it ever set up a church and needed a big cheese - specifically a 6-foot-7-inch, self-described Sasquatch who always has a tasteful gray suit handy - could not ask for a better preacher than Penn Jillette.

Eloquent, expansive, profane, very funny and not bad with a crowd, Jillette has been perfecting his skills for decades with Teller, the silent half of the magic act Penn & Teller. Now, Jillette, an outspoken libertarian, has written his own bible of sorts, complete with commandments whose earthy chapter headings King James just might object to.

"God, No! Signs You May Already Be an Atheist and Other Magical Tales" (Simon & Schuster; 231 pages; $24.99) is not only Jillette's godless manifesto; it's also a riotous and digressive memoir whose musings take in his upbringing in Greenfield ("Goyfield"), Mass., his cloistered family life in Las Vegas, and a hey-this-could-be-fun visit to San Francisco's old Club Baths in 1981.

Jillette spoke on a recent swing through San Francisco. His answers have been edited for length.

Q:Your book is officially out, and unless I'm mistaken, I don't see any evidence of you having been struck by lightning.

A: Better than that, on Twitter, when the earthquake happened in Virginia, there were several people who tweeted that the earthquake happened at the second that they either opened my book or the second that they ordered my book on Amazon. But I'm not sure that God cares about the publication of my book. But if he does, that'd be pretty cool.

Q:You write that "being an atheist is simply saying, 'I don't know.' " But it certainly sounds as if you do know that there is no God. Isn't "I don't know" more of an agnostic philosophy?

A: If I asked you, "Is there a God?" and you answer, "I don't know," then you are an agnostic, because you are answering an epistemological question, not a theological question. But if I say to you, "Do you believe in God?" that's a very different question, because I'm asking for the state of your faith. And if you've answered "I don't know" to the previous question, when I ask you "Do you believe"? unless you're crazy, the answer is no. You don't believe in things you don't know.

There are a lot of straw men in atheism. One straw man is, "You made up your mind, you wouldn't change your mind no matter what." And the answer is, well, you'd change your mind the instant you'd get a piece of evidence.

Q:Are agnostics more contemptible, in your opinion, than true believers?

A: I would just say sloppy. The kind of person I don't understand at all - I think there's a cute name on the Web for it - maybe "apatheistic." It's these people who say they don't care, it doesn't matter if there's a God or not, it has no impact on their life at all. That's the point of view I find the hardest to get a hold of. I just think that if there are people talking about everlasting life, if there are people talking about an omniscient, omnipotent, omnipresent being that controls their lives, I think I care about that.

A lot of people, to attack an outspoken atheist, one of the things they'll do is say, "You are as bad as the fundamentalist Christians." And my answer is always, "I hope so." I like them, I like that they speak with passion, I like that they're kind, I like that they believe in the marketplace of ideas. I just happen to disagree with the conclusion.

Q:Is it sometimes difficult to espouse atheism without sounding like an overbearing preacher?

A: No, I find if very easy. But atheism has the problem that our television show "Bull-!" had, which is you state things as a negative. But the real fact is that atheism is, when stated in the positive, a very simple sentence: Everything in this world is enough for me. The love of my family is enough - I don't need love outside of that. The security of my friends and other human beings is enough. The joy that I get from winning this astonishing lottery to be alive is so great I don't really want more.

Q:"Reading the Bible," you write, "is the fast track to atheism." How so?

A: You'll notice that in most of your Bible study groups, they don't ever say, just read the Bible from beginning to end. I think they know that that's a trap, that's a dangerous thing. If you just sit down without a guide and just read it from "In the beginning" to the way of Jesus at the end - when you go into the psychedelic revelation, mind-blowing stuff of one-eyed octopi running around the planet with Brad Pitt - I think at the end, you're going to see a level of cruelty and unpleasantness that if you are a humanitarian, the belief drifts away.

Q:You grab the reader by the collar much of the time, but what might stay with me the most is a tender story about your mother and balloons. Could you share it?

A: It's hard to talk about. I'm an amazing mama's boy. It's so fashionable - this is unfair, but it's also true - but in show business, everybody you talk to talks about how their family was dysfunctional. I mean, it's the start of everybody's act. Teller for one, and me, for two, had perfect relationships with our parents. They could not have been more supportive. My mom and I, as far as I could tell, were the same person; she was just in the body of a little old lady.

Teller will send balloons for anything - he's got the balloon guy on his payroll - and she had these balloons by her deathbed. She said, "When I die, let those balloons go, let them all go." And thus gave me a ritual. I don't think it's as well thought out or as universal as how good the Jews have it, I don't know if it's as cathartic as a standard Irish wake, but every year I do the balloons.

Q:Your parents didn't use obscenities around you. To what do you attribute your rich vocabulary?

A: You've hit a very important question here. My life, since I was 14: getting along with my parents perfectly, not ever having had a sip of alcohol, no recreational drug, never stolen anything, never having hit anybody in anger, never had any sort of brush with the law whatsoever, drive the speed limit, pretty much follow every rule that I'm given, really like people, can get along with most anyone. At some point, you gotta conceal that. I mean, I am a pussy!

I am by every definition the most Pollyanna, puritanical kind of milquetoast person possible. So you've got to grow your hair out, you've got to come in like a bear, you've got to say -sucker all the f- time, you've got to wear your atheism on your sleeve.

Q:You write that "Commercialism is beautiful and wonderful and open and real, and belief in Jesus is superficial and creepy zombie stuff." Have any churches sought you out to discuss your opinions?

A: Yes. A group of pastors just informed me that they're using my book at a big pastors' seminar. My video that I did on proselytizing is used by the Campus Crusade for Christ. And I have atheist friends - (Richard) Dawkins is one of them - who say, "What are you doing? By them bringing you in, that's giving them power." And I say, "We're not playing chess, we're living our lives as human beings. And they may like something I have to say."