If you know Penn & Teller — the famed magicians, humourists and debunkers, stars of the cable series Bullshit! — you know, broadly speaking, what to expect from their long-running show in Las Vegas and their appearance Wednesday at Massey Hall. If not, you might be surprised by Penn Jillette: first of all by how positively evangelical a man can be about atheism, and secondly by how happy he is to clash with genuinely who fervently disagree.

“We get a lot of people coming up to us after shows and saying ‘I’m a Christian but I really enjoy your passion,’ ” Jillette, 55, says on the phone from Sin City, where Penn & Teller’s show has been running at the Rio Hotel for nine years.

“There’s a big difference between tolerance and respect. Tolerance is you saying something crazy and me smiling and saying ‘that’s nice.’ Respect is when you say something crazy and I say ‘you’re out of your f---ing mind.’ Direct confrontation, direct conversation is real respect. And it’s amazing how many people get that.”

The duo’s gig in Toronto will be heavy on such frank talk — revealing magic’s secrets, singing the praises of rationalism and skepticism — and light on actual illusions. The Vegas crowd can enjoy Jillette and his mute stage partner Teller pretend to risk enormous harm by, for example, firing a nail gun into their flesh. Toronto gets a lecture, a trick or two and a Q&A session.

It’s no raw deal: 35 years of working with a wordless partner have turned Jillette, 55, into a gifted raconteur. He also does all the talking for the duo on Bullshit!, whose eighth season recently concluded on The Movie Network/Movie Central. On that repeatedly Emmy-nominated show, they’ve taken on, in investigative fashion, everyone from PETA to NASA, blasting the contradictions and nonsense they find within. But as it’s Halloween, a holy day for tricksters, we thought we’d ask him: what’s the nastiest trick you’ve ever seen anyone try to pull on the public on your show?

“That’s like asking what’s the worst video on MTV. The general idea that comes up a lot on Bullshit! is that when you combine the heart and the mind, there’s this horrible thing that happens . . . it’s solipsistic: ‘Because I feel something is true, it must be true.’ For 400 years now science has given us the power to stand outside ourselves.

“The big Bullshit! show that I pushed for was the anti-vaccination show. That’s the thing that’s costing lives.”

The notion that vaccination can cause autism — championed, until his study was withdrawn and his medical licence revoked, by British surgeon Andrew Wakefield — has been tied to declining vaccination rates in parts of the U.S. and a rise in whooping-cough cases. It was a topic Jillette had wanted to tackle for years, and the nastiest trick he has ever played doesn’t come close.

“Penn & Teller stopped doing practical jokes and the reason is we got much too good at it,” he says when prompted, casting his mind back a decade ore more. “We had a new agent — the same agent as Robert Wuhl, who was opening for us (in Atlantic City). We decided we would have a fight, and he (the agent) would have to break it up.

“It escalated into me holding (Wuhl) against the wall and him grabbing a pot of boiling hot coffee — that had been sitting there, steaming, for some time — and smashing it into Teller’s face. He was screaming, blistering, it was movie-quality acting and movie-quality special effects. We’d rigged the coffee, and we’d rigged the pot to break.

“The guy ended up quitting the agency, and he also, I’m told, refuses to believe it was a joke.”

Jillette, who co-produced and co-directed the comedy documentary The Aristocrats, is looking forward to Toronto — “It’s a real city, and it’s always a real pleasure to visit one” — and is disarmingly frank about his desire to visit a strip club while in town. As a man who doesn’t drink or gamble, the Massachusetts native is sanguine, too, about the real charms of life in Vegas: artistic freedom, of all things.

“Our bosses (at the Rio) don’t care about us at all. I mean that in the best way. They see the show once a year say ‘Wow, still great,’ ” he says, laughing at his own good fortune.

They’re no treat

We asked Penn Jillette: What are your five most-hated tricks of all time?

The linking rings: Oh my word. They’re solid rings (except for the gap under your hand) and they link. Even if you could do this for real, why would you?

The egg bag: The wooden egg is in a bag that’s made for the wooden egg to disappear, and then the wooden egg does disappear. Sometimes it’s a blown egg. What’s stupider than a blown egg? A wooden egg.

Any trick with a Mylar curtain behind it: Wouldn’t it be better to just have us close our eyes and promise us you were floating the under-paid dancer in the air, instead of just making it so we can’t see anything?

Any trick using a popular song: We’re listening to Jay-Z, not really caring about your stupid trick.

Any mind-reading or body-language reading tric: You can’t read minds, you can’t read body language, you’re not an expert in psychology — you are doing card tricks. When you say it’s something else, you are either really stupid or you think we are really stupid. Probably both.