FRANS DE WAAL: Well, religion is an interesting topic because religion is universal. All human societies believe in the supernatural. All human societies have a religion one way or another.

REZA ASLAN: Religion has been a part of the human experience from the beginning. In fact, we can trace the origin of religious experience to before homo sapiens. We can trace it with some measure of confidence to Neanderthals. We can measure it with a little less confidence all the way to homo erectus. So we're talking hundreds of thousands of years before our species even existed.

ROBERT SAPOLSKY: Essentially there has been no culture on Earth that has not invented some form of what could be termed meta-magical thinking, attributing things that cannot be seen, faith-based belief systems, things of that sort. It's universal.

ASLAN: Religious thinking is embedded in our cognitive processes. It is a mode of knowing. We're born with it. It's part of our DNA. The question then becomes why. There must be some evolutionary reason for it. There must be a reason, some adaptive advantage to having religious experience or faith experience. Otherwise it wouldn't exist.

SAPOLSKY: It makes perfect sense why they've evolved because they're wonderful mechanisms for reducing stress. It is an awful, terrifying world out there where bad things happen and we're all going to die eventually. And believing that there is something, someone responsible for it at least gives some stress reducing attributes built around understanding causality.

ALAIN DE BOTTON: Religion starts from the view that we are torn between good and evil. There is definitely a good core, but it's permanently tempted. And so what the individual needs is a structure which will constantly try and tug a person back towards the best of themselves.

DE WAAL: Our current religions are just 2,000 or 3,000 years old which is very young and our species is much older. And I cannot imagine that, for example, 100,000 years or 200,000 years our ancestors did not have some type of morality. Of course the had rules about how you should behave, what is fair, what is unfair, caring for others. All of these tendencies were in place already so they had a moral system. And then at some point we developed these present day religions which I think were sort of tacked onto the morality that we had. In societies with 1,000 or several thousand or millions of people we cannot all keep an eye on each other and that's maybe why we installed religions in these large scale societies where a god kept watch over everybody and maybe they served to codify them or to enforce them or to steer morality in a particular direction that we prefer. And so instead of saying morality comes from god or religion gave us morality, for me that's a big no-no.

PENN JILLETTE: People are good. If you look at the seven billion people on this planet just about seven billion of them are really good. We can really trust them. Can we please learn something from Las Vegas. Learn something about gambling, right. We know how the odds work. We know the house always wins. In this case the odds are always on someone being good.

BILL NYE: When it comes to ethics and morals and religion to see if there's anything different between what religions want you to do and what you feel you should do, what you think is ethically innate within you. For most people – most people are not inclined to murder people, but certain religions quite reasonably have rules against that. It's antisocial. See if that comes from within you or it comes from outside of you from without you.

ROB BELL: My understanding of spirituality is that this life that we've each been given, the very breath that we took and we're about to take is a gift. That life is a gift and how you respond to it, what you do with it matters.

PETE HOLMES: It's not about literal facts or the unfolding of what happened in the life of Jesus of Nazareth. It's a story because sometimes you need an explanation and sometimes you need a story. And a story is going to transform you and symbols are going to transform you. You see this in our culture. Batman is a symbol. Go out on the street and look at how many men, especially are wearing Batman shirts. It's a symbol. It's something that speaks to our psyche about the pain of a boy who lost his parents using his wound to become super and try and change his reality. That's a symbol. That's a Christ story. That's a hero story and we need those because it's not about at the end of the day winning a televised debate or finding DNA on the Shroud of Turin or proving his burial was here. I've been to Israel. I studied in Jerusalem. They're like he was crucified here and then they're like well, he was crucified here. Guess what? We didn't start writing that down until 150 years later because nobody gave a shit. It wasn't about that. It was about your inner transformation. You. Yours. I don't care how you get there. It can be photos from the Hubble telescope. It can be Buddhism, atheism, agnosticism, Catholicism. It doesn't matter. Who fucking cares. Whatever gets you there because we're talking about something. An energy that you can feel and be quiet to and respect, but most importantly you can flow with and dance with and feel and listen to and attune to.

BELL: This idea somehow that faith and science are in opposition I've always found to be complete insanity. Both are searching for the truth. Both have a sense of wonder and an expectation and exploration. They're each simply naming different aspects of the human experience. One thrives in naming exteriors – height, weight, gravitational pull, electromagnetic force. The other is about naming interiors – compassion, kindness, suffering, loss, heartache. They're both simply different ways of exploring different dimensions of the human experience.

FRANCIS COLLINS: Science is about trying to get rigorous answers to questions about how nature works and it's a very important process that's actually quite reliable if carried out correctly with generation of hypotheses and testing of those by accumulation of data and then drawing conclusions that are continually revisited to be sure they're right. So if you want to answer questions about how nature works, how biology works, for instance, science is the way to get there. But faith in its proper perspective is really asking a different set of questions and that's why I don't think there needs to be a conflict here. The kinds of questions that faith can help one address are more in the philosophical realm. Why are we all here? Why is there something instead of nothing? Is there a God? Isn't it clear that those aren't scientific questions and that science doesn't have much to say about them.

NYE: So the question is if you have a religious tenant, if you hold a point of view that excludes something about modern science I don't think the burden is on scientists or engineers to provide you a comfortable link. The link is for you. You have to reckon the facts as we call them with some belief system that is incompatible with it. An example that I think everybody would eventually find ourselves discussing would be geology, the age of the Earth. A couple of years ago I debated a guy who insists that the Earth is 6,000 years old. That's completely wrong. It's obviously wrong. And the way we know it is wrong was a result of centuries of study. People found layers of rocks, figured out where the layers came from. People found radioactive elements which chemically substitute into certain crystals in exchange like rubidium and strontium substitute for potassium and calcium and argon and so on. This led us to an understanding of the age of the Earth. So if you have a belief system that is incompatible with modern geology, really the problem is for the person trying to argue the Earth is extraordinarily young. Not for the people who have studied the world around us and understand it. There's nothing there that I've seen in the Bible that informs modern science with one possible exception. There's in some translations that I've read there's reference to 22/7 for being the distance around a circle, the value of pi. And that's pretty close. That's pretty close. It doesn't go past three digits but it's pretty close. Okay, so the people who wrote the Bible were literate but they were not literate in the modern scientific sense. So you have to reckon that, man. I can't get in there. The earth is not 6,000 years old. Never going to be.

COLLINS: My study of genetics certainly tells me incontrovertibly that Darwin was right about the nature of how living things have arrived on the scene by descent from a common ancestor under the influence of natural selection over very long periods of time. Darwin was amazingly insightful given how limited the molecular information he had was. Essentially it didn't exist. Now with the digital code of DNA we have the best possible proof of Darwin's theory that he could have imagined. So that certainly tells me something about the nature of living things. But it actually adds to my sense that this is an answer to a how question and it leaves the why question still hanging in the air. Why is it, for instance, that the constants that determine the behavior of matter and energy, like the gravitational constant, for instance, have precisely the value that they have to in order for there to be any complexity at all in the universe. That is fairly breathtaking in its lack of probability of ever having happened and it does make you think that a mind might have been involved in setting the stage. At the same time that does not imply necessarily that that mind is controlling the specific manipulations of things that are going on in the natural world. In fact, I would very much resist that idea. I think the laws of nature potentially could be the product of a mind. I think that's a defensible perspective, but once those laws are in place then I think nature goes on and science has the chance to be able to perceive how that works and what its consequences are.

BELL: Everything is driven by the desire to know the truth. There's an exploration. There's a wide-eyed sense of wonder. If you talk to the best scientists they have this sort of gleam in their eye like 'This is what we're learning. And we don't know what's actually around the corner.' And if you talk to the best theologians and poets and scholars they—ideally—have the same gleam in their eye which is 'Look what we're learning. Look what we're exploring.' And so to me they're not enemies. They're long lost dance partners.

COLLINS: Part of the problem is I think the extremists have occupied the stage. Those voices are the ones we hear. I think most people are actually kind of comfortable with the idea that science is a reliable way to learn about nature, but it's not the whole story and there's a place also for religion, for faith, for theology, for philosophy. But that harmony perspective doesn't get as much attention. Nobody is as interested in harmony as they are in conflict I'm afraid.

NYE: As you may know I'm not a believer. I'm a nonbeliever. I spent a lot of time trying to understand my place in the cosmos and I've reached my own conclusions but I'm the first to say that ultimately we are all agnostic. This is to say you can't know whether or not there is a giant entity running the show or choosing to not run the show. You can't know. So we all are I believe best served by just living good lives. Trying to leave the world better than we found it.

ASLAN: The truth of the matter is we just don't know. But what is a fact is that there is something in the way that our brains work that compel us to believe that we are more than just the sum of our material parts. That thing is either an echo or an accident or it's deliberate and purposeful. And which you decide is surely a matter of choice because there is no proof either way.