An interview with Stephen Unwin

Stephen Unwin has an impressive bio:

Stephen Unwin was born in Manchester, U.K. He attended Chetham’s Hospital School and obtained his bachelor’s degree in physics from Imperial College, University of London. For his research in the field of quantum gravity, he received his doctorate in theoretical physics from the University of Manchester. He has held the post of British technical attache to the United States Department of Energy, and is currently the president of his own consulting firm, specializing in risk analysis and risk management for Fortune 100 clients. He lives in Ohio.

To top all this off, he decided to write a book that would calculate the probability of God’s existence. After reading the book (my review is here) I thought Dr. Unwin would be fascinating person to talk to. I was right. Luckily for you I captured our conversation on tape (with his permission of course). The interview was conducted via phone and can be found below. The bold is me the non-bold is Dr. Unwin. Enjoy.

What led you to tackle such a huge subject ? the probability of God?s existence – for your first book?

I had a relatively religious upbringing and at the same time I was educated in the sciences; physics in particular. And while I was going through that educational process it never occurred to me that there could be any conflict between a religious description of the world and the naturalistic description I had been learning in science. And yet many years later when I came to the US with my job I became gradually aware of an ongoing debate that apparently put science and religion in conflict with one another, which seemed very counter-intuitive to me. So in many ways this project was to kind of help me think through, at least to my own satisfaction, why I had this perception that there was no conflict between the two.

It seemed to me that one of the characteristics of this debate was that both sides of the debate were extremely certain in their position. It occurred to me that really the legitimate position to take was one of uncertainty, in terms of the existence of God. So I kind of started from that point and I sort of hypothesized from the point that we were all really uncertain about whether God exits ? and all my professional life I had worked in the mathematics of uncertainty so it was a natural route to addressing the uncertainty to apply those sort of mathematical concepts. So the idea of calculating the probability of God in my mind was always a first step of that process, of understanding the role that uncertainty plays in the way we believe about God, and the way we talk about faith, and such things like that.

Was this an explanation of your thoughts or an experiment for you too?

Well, it was an experiment. I hadn?t really thought through the way I thought about it. I mean these were things I had basically taken for granted in terms of the absence of any conflict between my religious world outlook and my scientific world outlook. I was really forcing myself to think through an issue that I never had in the past, at least not in a systematic way. It was kind of putting my self on the spot in a way, to see how far the rational evidence would take me along the belief curve as far as God?s existence. Would it take me only a small part of the way, would it take me almost 100% of the way, or somewhere in between? I went in to this exercise with an honest – with no bias as to where I was going to come out at the end. When the numbers were actually produced it wasn?t some predetermined number I was trying to get to, it was legitimate outcome from that thought process.

At the beginning you take a moment to think about other ways to approach the probability of God?s existence. You discuss intelligent design and reject that option. Yet, the Bible seems to suggest nature as a way to God or at least a way people become aware of God. And certainly this has historically been used as a way to point to God?s existence. Why tackle Intelligent Design and why is that not a useful way to God?s existence?

Well for the reasons you state, it is often viewed as a crucial and central argument for God?s existence and that if he does exist he designed the world the way it is. I guess the conclusion I reached in the book, based on thinking through the facts, is that certainly we do live in a very structured world and things do give the appearance of design ? whatever that word design means ? but I really don?t believe that one needs to rely on a theistic view of the world to explain to the satisfaction of our own intellects why the world is the way it is. Now that is not to say that if God does exist that he wouldn?t be playing an absolutely crucial role in the way the world is. For example, people often argue, ?do you believe in creation or in evolution?? Well, I think that is a false conflict because I strongly believe in evolution. To my mind it is one the most successful natural theories in the history of the human intellect. Yet in my mind it is not at the expense of belief in God, I mean one can believe that those complex mechanisms were set up in some way. So if one has to concede design it is in the design of those mechanisms not in the more naïve engineering sense of someone sitting there with a blueprint of a human eye and building it that way.

Can you give a simple explanation of the anthropic principle and what you mean by it?

There are various types of descriptions of that principle put out there. There is the so-called strong anthropic principle and the weak anthropic principle. The strong anthropic principle is the one I do not discuss because it is very philosophically unsatisfying in my mind, says that somehow that the laws of nature were specifically tuned and created to result ultimately in the conditions that would be conducive to life, perhaps even human life. The weak anthropic principle, which to me is a very valid principle, is that the universe we would see around us is inevitably the universe that would be conducive to life. In other words, for there to be a perceiver of the things around us the world had to be just right to allow that perceiver to exist. A perceived universe, one that we can see and detect, really always would need to be conducive to life and the person doing the perceiving. I kind of joke in the book, in no universe would the comment be overheard ?Just as I thought, no life here.? It is a logical paradox

I also use the device of the little sign in the shopping mall. If you walk up to a sign in a shopping mall it has that little arrow that says, ?you are here.? Would you be surprised that the sign is exactly right? I mean it is kind of a miraculous manipulation that the sign was exactly right. It could have anything but it said just the right thing that you are here. Well, the answer is that it is your attributes that make it right. If you were standing somewhere else it wouldn?t be right but you wouldn?t be reading it in that case. So kind of in-built into it is its correctness. So the analogy is that the world is such that the person looking at it would always come into being. So you are always looking at a world conducive to life and structure.

Do you have in your mind a relationship between faith and science?

Well yes, faith is a word that can be used in many different contexts. The specific context and the way in which I talk about in the book and the way I envision it ? I go through this process of calculating the probability of God and what I mean by that is based on the evidence and rational analysis using the same sort of process you might use in a scientific analysis here is the probability of or likelihood of God based purely on reason. And I come up with a number that is 67% but then I say if you ask me off the top of my head ? more intuitively ? what?s the probability that God exists I wouldn?t say 67% I would probably give you a number that is far closer to 100%. What I say in the book is that that discrepancy, the discrepancy between 67% and 100%, that is explicitly the role that faith plays. It is a bit audacious I know but what I do is basically model the number of what the faith factor is so that it is something that accounts for the discrepancy between what is rational belief and what is the full belief. So in that sense the faith factor is really disconnected from the rational analysis by definition. But the situation isn?t all that simple because you ask in a more general sense what faith can be. And in that sense scientists have faith. The faith of a scientist is that reason or rationality is going to help him understand the natural world. We think and we look at the world around us and we take these tools of human reason like say mathematics and it proves to be a remarkably successful way to model the way the natural world works. I mean that is what physics is, it is modeling the way the world works in the language of math. Well you ask yourself did it have to be that way? Can we imagine a world where we come up with all these clever mathematical devices and yet it sheds no light on the physical workings of the world? I think scientists have faith in the fact that they can in principle uncover the way the physical world works by applying human reason and mathematics. So faith can be a very subtle thing. It insinuates itself even into atheistic beliefs. An atheist scientist at core has faith that reason can describe the way the world works.

In order to calculate the probability of God you set up a number of ?evidentiary areas? that weigh for and against that probability. How did you decide on these areas or narrow them down?

At first I just considered off the top of my head what were the key issues that were relevant to the questions of God?s existence. And then I supplemented them by reading the literature. There is no shortage of literature on this question of whether God exists and there are certain issues that are repeatedly the source of debate. So I adopted those issues. I don?t think I invented new issues. What was new was they way I incorporated them into the process. Often when you see an issue raised you see it raised by a devoted theist or atheist and they will use it as their case, proving their case and eliminating the uncertainties. Sometimes there are counter arguments but nevertheless that is the way the information is used. Well I took those same issues but instead of using them to narrow or eliminate uncertainties, I wanted to look at each issue and the counter arguments and see how they balanced and feed them into the process of rating those uncertainties. So for example, a lot of atheist say look at the existence of evil. Why would a good God that is all-powerful allow evil to exist. They use that as sort of their silver bullet argument against the theists. Well, of course the theists have counter arguments. Things like free will, which relies on the existence of evil because if you have no real choice you have no free will. What does it mean to make good decisions in life if you don?t have the option of making bad decisions? So these are never slam dunk issues, you know, you never have the other side throw up their arms and say you?ve got a good point there you?ve won. So rather than just argue one side of the issue, which is what you usually see, I tried to argue both sides to myself and look at the weight of evidence and feed them into the probability calculation.

After having weighed all the evidence and come to your conclusions, you then use this to discuss faith and reason and their relationship. One of the issues you raise is religious conflict. You have a unique view on this issue. Can you explain what conclusion you came to in this area?

I basically categorized various propositions ? first of all I discovered there were in my view probability type beliefs, based on analysis and reason, and there were faith based type beliefs. So I argued that there were these ways of believing in the truth of propositions. But now lets look at the nature of the propositions themselves. I argued that there were three categories in essence. There were categories to which you could apply both types of beliefs. Indeed, the probability that God exists would be the key example because you could reason the probability of that but clearly there is a faith factor. There are then those propositions that only rational analysis applies. As an example, you could say that automobiles exist and based on reasoned analysis and based on the facts you can believe 100% rationally in the existence of automobiles. There is no need for the faith component.

Importantly, I argue, there is a third type of proposition for which only a faith type belief would apply and not the logical belief. The reason I argue that is that there are certain propositions that are structured in a way where words are not being used in that proposition in their conventional application. There is really no logical foothold on what that proposition really means. And I try to make really clear in the beginning of the book that without a logical definition you have no starting point for a probability analysis because that really relies on you having an up front well-defined proposition. I give some examples of this. For example the proposition that God created the universe. For me that is a proposition for which you can have a faith belief but not a rational belief because that sentence is not using word in their conventional sense. We know what the word ?made? means or ?to make? but that is not really what that means in the context of that sentence. Making is an act that takes place in time, it is a construction, whereas creation of the universe – in the words of St. Augustine ? the universe was not created in time but was created with time. Time is an actual component of the universe just the way space is, I mean that is what comes out of Einstein?s theory of general relativity that time and space are actual components of the universe; they are not just a backdrop against which the universe exists.

So when someone says: ?God made the world? I for one, when I think about it rationally, don?t know what it means. So I have no starting point for which to do a probability analysis. One might have an intuitive understanding of what that means. It might mean that the world is somehow imbued with that distinction between right and wrong, between good and evil, and compassion versus indifference. So I might have a feeling inside me about what it means when someone says God made the world but certainly that feeling is no basis by which to do a probability analysis. I argue that many of the propositions that distinguish one religion from another are of that nature. So if someone says to me Jesus is the Son of God or Jesus is God as a Christian I attach belief to that. But I fully recognize within myself that it is faith belief. Now someone comes along and says that Jesus is not God. Well I argue, how can you have faith in that proposition; what does it mean? It is not like a logical proposition where you have the proposition and then the negation that is the opposite. Then you can attach a probability to one and the opposite to the negation. Faith just doesn?t work the same way; I mean how can you have faith that Jesus isn?t the Son of God? So that was the argument I tried to make was that faith type propositions don?t have the negations that logical propositions do. So there is no real basis for conflict in my mind. It is a sort of vacuous thing to argue one versus the other.

Is this a sort of way to use logic and probability as the basis for tolerance? That we avoid conflict with others when we are discussing these sorts of faith only areas because there is no agreed upon basis to discuss them?

Maybe even tolerance is too strong a word, because they believe something that is in conflict with what you believe but you are willing to accept it. I don?t think that is the situation. I think that there truly is no conflict; that the things you believe are not in conflict with the things they believe even though they are different. It?s not that you should tolerate those things that are in conflict with your beliefs but that those beliefs are not even in conflict in the first place just because of the form of the belief, the way it is believed. That yours is a perfectly legitimate faith based belief just as mine is a perfectly legitimate faith based belief.

The analogy I used is: take the proposition that Albany is the capital of New York state. Now someone might yes it is and someone might say no it is not. Those views are in conflict with each other. So I can see you being tolerant of the other guy. You say I think he is wrong but I am going to tolerate his beliefs. But now imagine that the two people believe things that are not in conflict; they are sort of talking past each other. They are not opposing viewpoints just different viewpoints. At that point you are not being tolerant just holding different but non-conflicting beliefs. I suppose the word tolerance is applicable there too but it is not that you are overcoming a disagreement it is just that you have non-conflicting beliefs. That was the way I argued it.

How do you account for the importance of ideas that come from faith-based belief? For example important points of Christian doctrine may be faith-based but they would lead to actions or ramifications that are important. Isn?t there conflict there? Doesn?t this slide into moral relativism?

I am not arguing that every belief that a Christian would hold wouldn?t be viewed as correct or incorrect relative to some other criterion. I happen to believe that when it comes to at least the major monotheistic faiths I see, in my experience, an almost complete overlap when it comes to the important things; like compassion, the difference between good and evil etc. Now I realize that is a huge oversimplification and that there are some political areas in which certain beliefs of a given faith, or interpretations of that belief, would lead you to believe that it has ramifications for the way people live their lives and perhaps the type of society we should form. I certainly don?t question that and yet, I honestly believe at heart that the important matters in terms of the things that the various faiths believe are really in conformance with one another. It is probably difficult to discuss it without specific examples but I can?t help but wonder to what degree our personal faith based beliefs should result in a wish to impose certain requirements on others. I think that is an awfully difficult sell in my mind. Of course it happens out there.

The vehicle should be persuasion rather than direct conflict?

I think so. I think it would be nice if the matters before us as a practical political matter were matters that each of the faiths would see the same way but of course there are counter-examples to that. I guess I didn?t really delve into that pragmatic an element of things; it was more a spiritual point that in my mind there is no real conflict. I mean you see Christians and Muslims arguing whether Jesus was the Son of God or not and it seems such ridiculous, vacuous things to be debating.

Either you get to that faith point or you don?t?

Yeah, that?s right. How can you argue against another person?s faith? Just because the nature of what it is. You can argue using rationality or reason to debate, that is what debate is about, using logical points to persuade the other person that the evidence is on your side. But when the issue is entirely faith based then there really is no starting point. I find those types of debates completely vacuous.

To return to the math, did you see the math as just a tool to get to the ideas or were you trying to communicate something about the math and the logic too?

It was not the main thrust of the book but there were certain aspects of the math ? although, as you know, the math is fairly rudimentary it?s not like there is anything really complicated in there ? but I thought readers would be interested in the way probability theory works. We all use the word probability and think in terms of probability but most people don?t have a specific knowledge of the way true mathematical probabilities work and behave and what they are, and how they are interpreted. People would be surprised, for example, that there is this debate in the world of probability as to how it is interpreted. You know there is the Bayesians versus the frequentists. I think most people are not aware that this is even an issue they think that probability theory has been wrapped up years ago just like basic arithmetic and now it just needs to be applied. But there is actually quite a thriving debate in the technical world as to what probabilities are. So I thought people would be interested in that given that probability is such a fundamental part of our way of thinking.

In a way, doing the probability calculation got me to a point where I could then start to contrast reason based versus faith based belief systems. So it put me in a nice position from that point on. I am not sure I could have gotten to that point quite as compellingly with having gone through the mathematical aspects. Although I would hope a lot of that would still hold if someone wanted to sort of skip over the calculation part.

Why is math seen as so hard? Why does it have that geeky connotation?

Very good question, and I agree with you there is that perception. I think people get scared of mathematics. Maybe they had a very bad experience with it when they were young and never got past a certain point so when they see math subsequently it brings a very fearful reaction. I wonder whether a lot of it depends on those early experiences of who the teacher was. People have said to me on a number of occasions, I wished you had been my math teacher. That is a real compliment because I like to be able to explain things that are inherently very complicated but in basic terms. It may have something to do with the educational system. I grew up in Britain of course so I didn?t live in the United States until I was an adult with my job. I mean certainly I wouldn?t claim that in Great Britain it?s that much different, that people embrace mathematics more but my memory and impression was that it wasn?t quite as fearful a subject over there; and maybe in other European countries as well. So I don?t know why that is the case, whether it is something cultural or has something to do with the way the subject is taught or what it is.

What drew you to your particular career in science? Kids don?t usually think when I grow up I want to be a quantum physicist.

Ever since I was very young I was interested in astronomy, in the universe, and in science in general. Then after secondary school I found I had a facility with math so that really took me and forced my interest in physics. Ever since I was about twelve or thirteen years old I knew that physics was what I wanted to do. And I always pursued the more theoretical and mathematical end of physics, which actually took me into theoretical physics, which I pursued right through to a Ph.D. and then a few years post-doctoral research. I loved it. But although I liked academia, I wanted to see what the real world was like and you can?t do theoretical physics to earn a practical living outside of academic circles. There was an organization called the United Kingdom Atomic Energy Authority and they had a policy of taking people out of academia and allowing them to pretty much come up the learning curve and teach themselves the technologies involved in safety and risk assessment. The mathematics in that field was not quite as sophisticated as in was in physics but it was still interesting enough that it would be challenge. So that was how I got into that field and I have worked in the risk assessment field ever since.

How did you come up with that first sentence? As I noted here before, I thought it was a great first sentence.

Well, I wanted to come up with something that would grab the reader, maybe something a little off the wall, yetrelated to probabilities. As to how I came up with that particular one, I can?t cast my mind back and recall exactly how I came up with it. I guess it just came to me and I said let?s go with it ? that should intrigue someone. Actually, there is always a danger that you are sort of trivializing the subject by using humor. Throughout the book, although there is a lot of humor injected here and there, I tried to do it in a way that was not at the expense of the serious themes of the book. I wanted it to be thought provoking but I wanted to be a fun read. I didn?t want it to be a tome on theology or math. I wanted it to be something people would enjoy reading as well as hopefully get something out of it in terms of new ideas.

I think people might need humor to rub the edges off a subject like this.

I think so. Books about math can be dull and books about theology can be dull so if you bring them together you really got the potential for it to be ?supernaturally dull? as it were. I didn?t want that to happen. I think the Philadelphia Enquirer had a review that sad it was ?pleasantly breezy? which I thought was a nice way of describing it.

What type of readers did you envision? Were you thinking of people that were already believers, people that had doubts, people that were diehard atheists?

To be honest with you, when I started writing it ? not being a professional writer of trade books ? I wasn?t writing it for an audience and thinking of it as a business proposition. I was really trying to get some thoughts down and help me get through the process; and maybe people with like view, people who held both religious and naturalistic views and wanted to reconcile them in their mind and how they were balancing those world outlooks. But then as I began writing it, it occurred to me that these issues might be of interest to anyone on the spectrum whether they were completely atheistic and would hopefully give them a way of understanding why other people think differently from them. And maybe even challenge them to go through the thought process and see just how different their numbers would be. And then at the other end of the spectrum people who already hold faith based religious beliefs who maybe want to analyze their own belief system the way I did. What?s amusing is that most people who talk to me want to me sign this book to someone else not to them and this is often an atheistic friend or relative or something ? which is kind of funny. I didn?t necessarily intend that for the book but it is a nice thought that they feel it might make someone think twice about their world outlook.

Is there one thing or concept that you would like people to come away with after having read the book?

I would like people to come away with the idea that rational belief and faith based belief are in no way in conflict with one another; that they are reconcilable and understandable. I would hope people would come away thinking a little differently about what faith is and what faith versus reason is. As your are aware, in the appendix I put together a little spread sheet which will allow someone else to go through my thought process but using their own evidence and their own numbers. I would really challenge someone to come up with a number that is either very close to zero or very close to 100%. I can?t imagine how someone would do that thinking it through in the way I thought it through. I was thinking maybe on my website, once people had had a chance to read it, of asking for input on what numbers people came up with when they applied that reason process. I would be curious to see what the range is. I certainly under no illusions that someone would come out within a narrow band of my number, that would surprise me, but it would also surprise me if people were able to see and interpret the evidence in a way which pushes the number way towards 0 or 100. I just don?t see that as a reasonable conclusion to model what we see out there.

Kevin Holtsberry
I work in communications and public affairs. I try to squeeze in as much reading as I can while still spending time with my wife and two kids (and cheering on the Pittsburgh Steelers and Michigan Wolverines during football season).


  1. Mr. Unwins calculations may put a figure on the probabilty of the existence of ‘something’ but I don’t think that from his calculations it can be decided that this ‘something’ is necessarily the christian god. It might be Vishnu, or more probable, considering the complexity of the initial creation and subsequent overseeing process, it could be ‘the God and Universe foundation’ complete with Board of Directors with rotating Chairmanship, Miracle Task Groups , PR-division and the like.

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