Reza Aslan's new book God: A Human History is a remarkable document. It lays out the entirety of human's relationship with the divine, using athropological and archaeological documentation. From pantheism to ancestor worship to monotheism, Aslan examines the way that a concept of a higher power has evolved right alongside human civilization — and also helped shape our modern world. Aslan was in Seattle last week with Seattle Arts and Lectures. We spoke on the phone shortly after his arrival in Portland for the next reading on his tour. What follows is a lightly edited transcript of our conversation.

I’m an atheist but I've always been very fascinated with belief and the way that you approach this book. I thought it was really informative for the purposes of talking with people about faith — and not just religious faith. At my day job, I work in messaging and political economy. And I’ve found that when we talk about raising the minimum wage to $15 per hour, for example, people would respond, 'well, you can’t pay $15 per hour because the market says they’re not worth $15 per hour.' The market is a creation of people, and other nations have much higher minimum wages than we do here in America so there’s proof that it can work, but once people offload it to this inhuman, unknowable force —this market — there’s a barrier. You hit a wall in your conversation, and it seems insurmountable. Has your work with so many different religions taught you anything about talking across that wall?

If you think of a faith as a kind of worldview then it's understandable why occasionally it becomes difficult to actually have conversations. This wall that you're talking about — essentially, you're talking about two different perspectives, two different points of view. And often it's not that you are arguing over the merits of some kind of point, but what you're really doing is talking about two different ways of seeing the world. And so those kinds of conflicts sometimes come naturally.

Part of what I try to do, not just with this book but most of my works, is to try to reframe the conversation and to redefine certain terms. For instance, you call yourself an atheist, which I imagine means that you don't believe in God. But I do think that in order to actually have a conversation with you, we'd have to first talk about what you even mean by God, because it's very likely that your definition of God and my definition of God are vastly different from each other — and so having that understanding would mean that you and I perhaps are much closer in our points of view than we actually thought that we were.

And particularly when you're talking about faith issues, we have this weird perception that we all mean the same thing when we use this most complex of words, and so often the arguments that we find ourselves having dissipate once we start with this fundamental question of 'what do you mean? What is your perspective?' That's something that I try to bring to all the work that I do.

One of the things that I really enjoyed about this book was the way you embrace the ambiguity of the anthropological record. I think about that hackneyed idea of what would happen if an alien anthropologist found our ruined civilization in the future and if they only had access to one site, it would change their understanding of our faith. If they found a church, they would imagine us as a monotheistic religious culture. If they found a multiplex, they might think that we were a pantheistic religion worshipping superheroes. And if they found Washington DC, they might think we were big into ancestor worship. Do you think about what you’re missing when you look back on the past?

It’s a fun game to play. The difference of course being that we are products of a written culture, and once you start writing things down, those things stay forever. When we're talking about religion, however, and particularly when we're talking about prehistoric religiosity, which is where my book begins, you are talking about a preliterate culture and so that makes it much more difficult to draw conclusions with any measure of certainty.

We do have an enormous amount of material evidence at our disposal when trying to talk about things like the origins of the religious experience. We have at our disposal temples and idols and the spectacularly painted caves that bear remarkable signs of ritualistic thinking. And so we can look at this material and we can give our best guess as to what it means and how it functions.

But before the advent of writing, we are essentially shooting in the dark. What we have going for us particularly in my field of religious studies is that we can combine the anthropological and archaeological data. We can use what we know about sociology in order to draw certain conclusions and we can make pretty good guesses. But in the end, they are guesses.

In the book, you refer to the advent of agriculture as a net negative for society, and I was wondering if I could ask you about that, and maybe your perspective on how that has shaped human history.

To begin with, this is now more or less the consensus view. The traditional view was that after tens of thousands of years as hunter-gatherers, we began to plant our food and domesticate animals as a means of ensuring a greater food supply, and that doing so resulted in more stable food supplies and also in more calories, more food. And that allowed us to actually settle down and then create civilization, and then, of course, history as we know it.

Well, unfortunately, that traditional view just doesn't hold up any longer to the archaeological evidence. First and foremost we now know that we human beings had settled for thousands of years before the rise of agriculture. So that upends the notion that we settled down because we started planting — now, it turns out that we settled down for quite some time before we ever thought to start planting. So that in and of itself had to have to shift the way that we even think about why we started planting.

And then secondly we now have ample evidence to indicate that far from creating a surplus of food, the agricultural revolution actually diminished our food supply — and quite dramatically. It provided far fewer calories, far less protein, and if that weren't enough, it actually introduced a whole host of ailments and diseases that were completely new to the human condition. The great Israeli historian Yuval Hariri has this great line where he says homo sapien skeletons were simply not evolutionarily designed for farming. That's just not what our bodies were meant to do. He refers to the agricultural revolution as history's greatest fraud.

Now this idea that the agricultural revolution was not an advantage to human beings raises a more fundamental question which is: why, then, why did we start doing it? Why did we start farming, knowing that a bad crop would result in the deaths of everybody in the village? Why did we start domesticating and penning animals, knowing that a disease in one of those animals would wipe out the entire herd and kill everybody in the village? Why did we do all of these things, when it required far more effort and work than hunting and gathering did, for far fewer calories? Why did we do it? It makes no sense.

There have been a number of attempts to answer that question, from environmental changes to the thinning or extinction of herds — none of which have been borne out by the evidence to date. One of the more innovative answers to that question happened to do with the institution of religion. And what I mean is, the movement from the prehistoric animism that fueled our ancient ancestors to the establishment of temples and institutionalized worship — it was the institutionalization of religion that led to the settlements, to the idea that we actually settled down and stopped wandering.

And then once we settled down, that that caused the slow move towards experimenting with agriculture and with domestication. Again, this is one of those things where we're giving our best guess. We're looking at the evidence that's available to us, and we're trying to interpret it as much as possible.

But I think that the reason that there is an enormous amount of enthusiasm for that particular interpretation of 'why agriculture?' is because all the other answers don't work. So much of what this is about is simply ticking off things that don't make any sense or that don't fit with the available data and seeing what's left.

We do know, of course, that the earliest experimentations with plants and the domestication of animals took place in southeastern Turkey and in the Levant area. These are the earliest examples of settled communities, and we also know that [these regions hosted] the earliest expression of institutionalized religion, and that those things really affected each other. And so the theory is that it was in fact the advent of hierarchical institutionalized temple-based religion that resulted in the need for the transition to agriculture, despite the fact that it was not a good bet on the part of humanity — that it did not lead in those first couple of thousand years to more food or a more stable supply.

And by the way, part of the reason why I think people even people who don't study religions gravitate toward this theory is that the one thing that we all know about religion is it makes you do things that aren't necessarily helpful. The thing about religion is that you do sometimes irrational things in the name of religion and the you know the agricultural transition was by all accounts any rational thing.

So in a way, religion also established the inequity that we still see today?

You know, the standard sociological answer to this is when we went from wandering to settled, being settled allowed for the accumulation of wealth and the disparity in society in a way that wandering would not allow. The nomadic lifestyle doesn't really allow for the accumulation of wealth, or the stratification of society. Settlement does. And if you think that settlement was a direct result of certain religious changes that took place, then yes, once again religion becomes the culprit for the sudden disparity in society.

I love your example in the book of the talking tree — the theory that we can accept one or two divergences from what we know, but that if you keep adding unbelievable ideas, you reach a breaking point.

This is a fascinating theory — and it is a theory, but it's a pretty good one. It was first developed by a cognitive anthropologist by the name of Pacal Boyer. And what he was trying to figure out was a simple question: Why do some religious beliefs stick and some don't?

Obviously, he's a scientist so the answer that is often given, which is ‘the ones that are true stick, and the ones that are false don't’ just doesn't work for him. And so he began to do these very interesting studies about how our brains actually hold onto information, and particularly when that information is anomalous in some way. Why do we hold on to it? How do we hold on to it? When do we get rid of it?

And what he discovered was exactly what you say — this thing that has been now dubbed the minimally counterintuitive concept. The basic theory is that when the mind is confronted with something that is only slightly abnormal, something that that essentially violates the core function or characteristic of a saying only slightly, there is something about the brain that holds on to that idea, that anomalous information much more so than if a thing is too anomalous.

So the example that I gave in the book is a tree that talks. A tree that talks is only slightly anomalous. It's the kind of thing that the brain holds onto and is more likely to pass on. But a tree that talks and also has the ability to be invisible and also can move from place to place — now you're violating far too many categories of the idea of a tree, and the brain simply doesn't have the ability to hold onto that. [Boyer] uses this cognitive theory to explain why some religious beliefs stick around and others do not. It’s a really fascinating idea.

Of course the thesis of my book, the point that I'm trying to make, is that of all these minimally counterintuitive concepts that have ever existed in human history, the one that is most successful is the idea of the superhuman — the human who is altered in some slight way. And that where our conception of the divine arose, is this notion of a person who has shifted in a slight way, is given a certain kind of power. That is an explanation for how this natural impulse towards transcendence — towards that which lies beyond the material realm — is something that is part of our cognitive process. It's who we are, it’s how our brains work: that natural impulse often becomes actualized or concretized in the form of a divine human, or a human who is divine, because of this minimally counter-intuitive concept that arises in our brain.

It seems to me to be an exaggeration of something that’s a standard part of the human experience. Your knowledge, your experiences, make you special — kind of a superhuman. That’s why we contacted your publicist for an interview and why we’re talking. Everyone does something special — you know, I make a pretty okay chili. So is this search for the supernatural a recognition of us as we are or is it a desire for more? Is it aspirational, or is it a reflection?

It’s a reflection, it's an innate compulsion. One thing that I make very clear in the book is that I'm not making an argument for the existence or nonexistence of God. That's not an argument I am interested in having — mainly because there is no proof either way.

What I am interested in is how we have expressed faith. It is deeply embedded in this cognitive impulse that you were referring to, this innate unconscious compulsion to humanize the divine — to essentially project one's own personality, one's own emotions one's own virtues and vices and strengths and weaknesses and biases and bigotries upon the divine.

What’s truly remarkable about this impulse, and why I think it's just a function of our brains, is that even atheists do this. When you say to someone who is a you know an atheist, who doesn't believe in God, studies show that when you ask that person to then describe what they mean by God, they do what believers do. They begin to describe a kind of divine version of themselves. They begin to talk about a divine personality who looks and feels and acts and thinks very much the way that they do. So it doesn't matter whether you're a believer or not, it doesn't matter whether you are aware of it or not. The fact of the matter is that most of us when we think of the idea of God, what we do is we think of a divine version of ourselves.

You have a few passages in the book where you write about soul, and I thought some of the passages seemed to be in conversation with Lesley Hazleton’s book on agnosticism, and I was curious if you had read it or if if that was something coincidental.

I have read Lesley's book — I think I actually even blurbed it — but no, that's not in in conversation with anyone. The issue is that we were born with this conception of substance dualism, this innate notion that there is a distinction between the body and mind. What that means, nobody knows — it doesn't prove God, it doesn't disprove God. It doesn't mean that we are believers and we have to learn to be unbelievers. We don't know what it means, but it is a fact, and studies have routinely pointed this out. So it must be part of again our cognitive impulses, must be just a thing that happens in our brains. What I'm interested in, is what that actually means and how and how to make sense of that.

Evolutionarily speaking, we don't have a good answer for the universal belief in what is come to be called the soul. You can call it what you want: you can call it the psyche if you want to, you can call it Brahma, you can call it whatever you want, but we all mean the same thing — this kind of spiritual essence, if you will. It's universal. It exists in all cultures, in all religions, and throughout all time. And we don't know why! There isn't a good reason to explain this innate sense. And so I go back to where I began the book, which is ultimately it's just a choice.

It’s a decision on the individual's part to give that fact some kind of meaning. And you could be someone who says ‘it's just an accident, just a meaningless cognitive blip.’ Or you could be someone who thinks that it's not just on purpose, but it's by design: it's who is how we are made it's who we are and we're supposed to have that that feeling, that sense of innate spiritual essence. We’re back where we started, right? It's up to you! There's no proof either way.

But I do think that at the very least coming to an understanding of these things is a good way to start a conversation between people, between believers and nonbelievers, and between believers of different religions.