"There are really good sociobiological reasons for why we evolved to cooperate. It really is good for all of us. You can be a hard ass and just run common sense, you know, what is the most effective way for people to interact and you do better if you treat people well, you just do. And on top of that the whole world does better if you treat people well. It works out on any level."

“There Is No God" on This I Believe”

“The question I get asked by religious people all the time is, without God, what’s to stop me from raping all I want? And my answer is: I do rape all I want. And the amount I want is zero. And I do murder all I want, and the amount I want is zero. The fact that these people think that if they didn’t have this person watching over them that they would go on killing, raping rampages is the most self-damning thing I can imagine. I don't want to do that. Right now, without any god, I don't want to jump across this table and strangle you. I have no desire to strangle you. I have no desire to flip you over and rape you.”

“Penn Jillette/The magician-comedian-writer's secrets revealed! – Slate, ۴ فوریه ۲۰۰۶”

“Penn's home "The Slammer”

“Rabbi Daniel Lapin: Here's a really blunt question: would the world be a better or a worse place if a billion Muslims became evangelical Christians tomorrow?”

“I can read ideas from all different people from all different cultures. Without God, we can agree on reality, and I can keep learning where I'm wrong. We can all keep adjusting, so we can really communicate. I don't travel in circles where people say, "I have faith, I believe this in my heart and nothing you can say or do can shake my faith." That's just a long-winded religious way to say, "shut up," or another two words that the FCC likes less.”