An Afternoon with John Polkinghorne

This UCSD-TV program is a presentation of University of California Television for educational and non-commercial use only. What we're doing this afternoon will be divided into two segments with an intermission in between. So the first segment will feature a lecture by Dr. Polkinghorne entitled the friendship of science and religion. And the second part of our afternoon will be an in-depth, personal, and quite interesting interview with Dr. Polkinghorne conducted by Dr. Dean Nelson, one of my colleagues here and professor of journalism and the co-author of a forthcoming biography of Dr. Polkinghorne's life. So I hope you can sense that we have a very special event to share together for a little while this afternoon. Dr. Polkinghorne was, for 25 years, an active, engaged, leading theoretical physicist. He has made major contributions in the area of theory associated with elementary particles, made key observations, key contributions related to the discovery of quarks, became a fellow of the Royal Society, and in 1979, at the very pinnacle of his career, he left that role of being an active theoretical physicist to become a priest. In 1982, three years later, was ordained into the Church of England and took a parish in England, which he served for five years before moving back to Cambridge University, where he had been prior to that as a theoretical physicist, initially to become Dean of the Chapel at Queen's College, and then to become President of Queen's College, which he served until 1996. Following soon after that, he was ordained, sorry, he was knighted by the Queen of England, and in 2002, he received what is probably the closest thing to the Nobel Prize as it relates to science and religion, and that's the Templeton Prize received in 2002. So although he retired from the role of being the President of Queen's College in 1996, which was a long time ago, 14 years ago, Dr. Polkinghorne has continued to serve the community by speaking and writing and doing a wonderful job in terms of leadership on this area, and so what a privilege it is for us to have Dr. John Polkinghorne here this afternoon to speak on the topic, the friendship of science and religion. Dr. Polkinghorne. You've just heard, I'm a scientist and a Christian. More specifically, I'm a physicist and an Anglican priest. And when people hear that, they sometimes give you a funny look, a sort of mixture of incredulity and suspicion, as if you'd said, I'm a vegetarian butcher. Because there are many people out there, and there may be some people in here who think that science and religion are actually at war with each other, and you really ought to decide which of the battle lines you're going to join. Now, of course, I don't agree with that. I think that science and religion are friends and not foes. I think the basic reason that they're friends is that they're both concerned with the search for truth. The search for truth to be attained through motivated belief. The question of truth is as important to religion as it is to science. Religious belief will do all sorts of things for you, can guide you in life, and strengthen you in the approach of death. It can't really do any of these things, unless it's actually true. So the question of truth is central to religion. People sometimes say science is concerned with fact, and religion is just concerned with opinion. In other words, science is true, and religion might be true for you, but not really true in any absolute sense. I think to say that is actually to make two bad mistakes. Make the mistake about science, because in science there are no interesting facts that are not already interpreted facts. There is a sort of circularity in science between theory and experiment. Theory interprets what's being measured in experiments. Experiments either confirm or disconfirm theories. The relationship between them is much more subtle. It's simply the confrontation of indubitable prediction against unquestionable results. So science is subtle in that sort of way. And religion is concerned with truth. Religious faith is not a question of shutting your eyes, gritting your teeth, leaving six impossible things before breakfast. Some unquestionable authority tells you that's what you've got to do. In other words, you're told you have to commit intellectual suicide. I could not be a religious believer if I thought that was the case. So science and religion are both concerned with truth, but of course they're concerned with different dimensions of truth. They are, for example, asking different questions about the world. Science is asking essentially a single question about what's going on in the world. It asks the question of how things happen. What is the process of the world? And of course, science has been astonishingly successful in finding answers to those questions. We should be grateful for that, and we should take the offerings of science in that respect with absolute seriousness and gratitude. But there are many other questions that it's both meaningful and necessary to ask about the world, which science, if it's honest to itself, does not pretend to be able to address. There are questions of meaning and value and purpose, but science doesn't address those particular issues. Nevertheless, we all know that these are sensible and necessary questions to ask. We all know that you can ask and answer both the how question, how things are happening, and the why question, is there meaning and purpose in what's going on? We can ask and answer both those questions about the same event. Burning gas heats the water and makes the kettle boil. The kettle is boiling because I want to make a cup of tea. Would you like to have one? One is science's answer of how, the other is an answer in terms of meaning and purpose, a why question, why the kettle is boiling. I don't have to choose between the answers to those two questions. In fact, if I'm to understand the mysterious event of the boiling kettle, I need both those kinds of answers to tell me what's going on. And so in a similar way, I think I need the insights of science and the insights of religion. If I'm to understand the rich and many-layered world in which we live. Science and religion also address a different level in our experience of encounter with reality. Essentially, science treats the world objectively. It treats the world as an it, as an object, something that you can carry around, pull apart, and find out what it's made of. And that gives science its great secret weapon, the power of experiment. I was a theoretical physicist, a sort of pencil and paper chap, but I would gladly acknowledge that my subject in the 25 years or so I worked in it was largely experimentally driven. Scientists are able to put things to the test because in the realm of the impersonal, you could just repeat things again and again and again until you feel convinced about what is actually happening. If you don't agree what an experimental scientist tells you, in principle and even sometimes in practice, you can do it for yourself. But we all know there is another realm of encounter with reality, where we meet reality not as an it, as an object, but if you like, as a thou, we meet personal reality. And when we enter the realm of the personal, and even more of the transpersonal realm of encounter with the reality of God, we enter a domain where there isn't repetition at our disposal. Where truth and understanding is to be found by commitment and trusting, not by testing. If I'm always setting little traps to see if you're my friend, I shall quite soon destroy the possibility of friendship between us, because I can only be based on mutual respect and mutual trust. And it's even more true in the spiritual realm that you shall not put the Lord your God to the test. The attempt to manipulate God is the foolish error of magic. So there are differences between these two realms of inquiry, and differences therefore about the kind of truth that they're looking for. Nevertheless, how you answer the how question and how you answer the why question, though they are different questions, nevertheless the answers must somehow fit together in some way that makes sense. If I were to say to you, I'm going to make a cup of tea, and I put the kettle in the refrigerator, you would doubt the genuineness of my statement. So there has to be a consonance, there has to be a congruence between science's answer to the how question and religion's answer to the why question. And that means that science and religion are not totally independent of each other. They are friends, they have things to say to each other, they have gifts to offer to each other. But there has to be a dialogue between them, because the insights that they're offering have to fit together to make a broader and a deeper account of the remarkable reality of the world in which we live. Certainly science by itself could never be enough, in my view, for us to understand the world in which we live. It has purchased its very, very great success by the modesty of its ambition, by restricting itself to this kind of experience and to asking this kind of question. Science trawls experience with a coarse-grained net, and many of the things of the greatest significance slip through the wired meshes of the scientific net. If you were to ask a scientist, as a scientist, to tell you all that he or she could about music, I think speakers of science, they would say something like this. Music is neural response, things far off inside our brains, to the impact of sound waves on the eardrum. Of course that's true, and in its way it's worth knowing, but it hardly exhausts the mystery of music, does it? I think if that same person were asked to say what they thought about music as a person, he or she would have very much more to say. They want to discuss the truly remarkable way in which that sequence of sounds in time can speak to us, and I think speak to us truly, of a timeless realm of beauty. The world that science describes is very interesting, very exciting to explore, but it's a kind of lunar landscape. It is populated by information processing, replicating beings, but there are no persons in it. And if we're going to understand the universe in which we live, we need the insights of both science and religion. Okay, I think all that means that science and religion have gifts to offer each other, in their common quest for truthful understanding. And I want to just draw your attention to a particularly important gift that I think science gives to religion, and two gifts that I think religion can offer to science. Those are very important gifts. We should take them absolutely seriously. We should take them gratefully. It grieves me sometimes when I see Christian people who are refusing the truthful insights of science, who deliberately turn away from them. I think that is a very sad. Those who are seeking to serve the God of truth should always welcome truth, and never fear truth, from whatever source it may come. Not all the truth by any means will come from science, but some of it will. One of the most important insights that science has to offer us about the world in which we live is that its history, in particular the history of life here on earth, has been a long and evolving history. I think the insights of evolution are very important gifts to religious people seeking to understand God's creation. There's a sort of myth in our society that in 1859, when Charles Darwin published his great work, The Origin of Species, that was the real parting of the ways between science and religion. According to the myth, all the scientific people shouted, yes, yes, yes, to Darwin's ideas, and all the religious people shouted, particularly, of course, the obscurantist clergy shouted, no, no, no. Now that's just historically ignorant. There was a mixed reaction in both communities. There were quite a lot of scientists who didn't welcome, or didn't accept, Darwin's ideas. Sir Richard Owen, who was the greatest comparative anatomist of the day, never accepted Darwin's ideas. The problem was that Darwin had to appeal to successive small differences between generations, but Darwin was a very straightforward and honest man. He acknowledged he did not know where those differences came from. But Mendel published his ideas in an obscure Central European journal, and nobody noticed them. It was only in the 20th century, when genetic ideas were recovered independently, that people were able to put them together with Darwin's evolutionary ideas to give us the modern understanding of the nature of life. Now on the religious side, there were people who welcomed Darwin's ideas from the start. Asa Gray, professor of botany at Harvard, was one of them. In my own country, one of the most important was a close human friend of Darwin's, Charles Kingsley, who was also a novelist. Kingsley, very soon after the publication of The Origin of Species, coined the phrase that I think perfectly sums up how to think theologically, how to think from a religious point of view about the fact of biological evolution. And what Kingsley said was this, he said, no doubt, he said, no doubt God could have snapped the divine fingers and brought into being a ready-made world. But Darwin had shown us that God had done something cleverer than that. God had brought into being a creation so endowed with potentiality that creatures could be allowed to explore and bring that potentiality to birth. Creatures could be allowed to make themselves. That's the way to think about an evolving universe from a theological point of view. It is a world in which creatures are allowed by their creator, but within limits of course, allowed by their creator to make themselves. And if you think about it, I think that that's, if I may venture to say so, that was a very fitting form of creation for the creator to bring into being. Because you see, Christian theology has to steer a course in thinking about God's relationship to creation. It has to steer a course between two unacceptable extremes. One extreme is the God of deism, the spectator God, who simply sets the world spinning and stands back and watches what happens. That can't be the God of love. The God of love must have concern for creation. But loving concern can never be tyrannical. The God of love cannot be a cosmic tyrant whose creation is a sort of divine puppet theatre in which God and God alone pulls every string. We all know, we know as parents incidentally, that loving our children, we have to allow them as they grow up to be themselves and to make themselves. The gift of love is always the gift of some appropriate degree of independence to the objects of love. And bringing into being a creation in which creatures are allowed to make themselves in that way is, I think, precisely the kind of creation that we might anyway with hindsight expect the God of love to have brought into being. So an evolving creation in which creatures make themselves is a great good, but it has a necessary cost to it. Because the explorations of potentiality which bring to birth fruitful new forms of life, which have turned over three and a half billion years a world which for more than two billion years only had bacteria in it, now to a world that has you and me in it, rich and complex beings, those processes will not only have fruitfulness, but they will also at times have blind alleys and ragged edges. You can't have one without the other. The engine which has driven biological mutation, biological evolution in this country has of course been genetic mutation, bringing into being new forms of life. When germ cells mutate, new forms of life come into being which can be then sifted and preserved by the processes of natural selection. But if germ cells are going to be able to mutate and produce fruitfulness in that sort of way, it's inevitable that somatic cells, body cells, will also be allowed to mutate. And sometimes when that happens, they will become malignant. The fact of cancer in the world, which is of course an anguishing fact about the world, I don't wish for a minute to deny that or to suggest there's some simple one-line answer that removes our perplexity and indeed our anger about that fact. But it is not gratuitous. It is the inescapable shadow side of the greater good of a creation which creatures make themselves. We all tend to feel of course that if we'd been in charge of creation, we would have done it better. We would have kept all the nice things and thrown away all the nasty things. But the more science helps us to understand how the world actually works, the more we see these things are inextricably entangled with each other. You can't pull them apart. Here's the good things, keep those. Here's the bad things, keep those. So the fact of cancer in the world is not gratuitous. It's not due to God being callous or incompetent in some sort of way. It's the inescapable shadow side of a creation which creatures make themselves. Now I'm not suggesting for a minute that this removes all our perplexities and difficulties about evil and suffering in the world. Well, it doesn't. But I do think it is mildly and truly helpful to those of us who wrestle with what is surely religiously the most disturbing and puzzling problem, which is the problem of evil and suffering. So that's a great gift in my view. A great gift that science gives to religion. Now what gifts could religion give to science? Well, certainly not to answer science's questions for it. I think we have every reason to believe that scientifically stateable questions will receive, eventually, scientifically stateable answers. Sometimes they're very hard to find. For example, we don't understand today the biochemical pathways by which life first began here on Earth. But I hope that one day we will. So I think the role of theology is not as a rival to science, saying, I'll answer your questions for it. I'll tell you what to think. It's not to be in conflict or rivalry with science, but to complement science. To set science's undoubted insights within a broader and deeper context of understanding. To make things intelligible, which from a scientific point of view have to be treated simply as brute facts. It's very interesting that there are questions that arise out of our experience of doing science, but which are not in themselves scientific in character. And therefore, science is not in a position to answer them, but nevertheless are meaningful and necessary to ask. And I want to just briefly draw your attention to two of those questions. The first of them is actually a very simple question. It's so simple that most of the time we don't even stop to think about it. But I want to suggest to you that it is worth stopping and thinking about it. And it's simply this. Why is science possible at all in the deep way in which it has proved to be? Well, you might say that's pretty easy. Evolutionary processes must have so shaped our ancestors' minds that they may well understand the world in which they lived and so to survive in that world. And I don't doubt for a minute that that is an important part of the process. But our powers to understand the universe, the deep transparency of the universe through our inquiry, goes far, far beyond anything that is either needed for everyday survival or could be considered to be some sort of happy spinoff of everyday survival necessity. I mean, it's one thing you want to figure out it's a bad idea to step off the top of a high cliff. But something quite different happens when somebody like Isaac Newton comes along. And an astonishing creative leap of the human imagination sees that the same force that makes the high cliff dangerous is also the force that holds the moon in its orbit around the earth, the earth in its orbit around the sun, to discover the mathematically beautiful law of universal inverse square law of gravity, and in terms of that, to be able to explain the behavior of the whole solar system. That has no everyday survival utility. But it's a very deep and intellectually satisfying kind of understanding that science has been able to give us about the world in which we live. I hope that people still read Sherlock Holmes. If they do, you may all recall that in the study in Scotland, which is when Holmes and Watson first meet, they are having, I think they're having breakfast in a hotel together, but anyway, they're having a conversation. And Holmes is pulling Watson's leg from the start. And in the course of their conversation he says, I don't know, he says, I don't know, does the earth go around the sun or does the sun go around the earth? And the good doctor is horrified at this apparent ignorance on the part of the great detective. Holmes simply says, what does it matter? My daily life as a detective? Of course it doesn't matter at all. Nevertheless, we all know many things and should be grateful for knowing many things that we do not need for our everyday life and everyday survival. So why is science possible in the deep way that it's proved to be? And in fact, the mystery is deeper than that, because it turns out that the key to unlocking these fundamental secrets of the universe is that most abstract of subjects. It is mathematics. Good news for some, not such good news for others, perhaps. It's an actual technique of discovery in fundamental physics, to look for theories which in their formulation are described in terms of what mathematicians can recognize and agree about as being beautiful equations. Some of you will know about mathematical beauty, perhaps not all of you, it's a rather austere form of aesthetic pleasure. It involves qualities like being economic and elegant, and also something that the mathematicians call being deep, which means you take a very simple-looking starting point, a simple-looking definition, and you find that it has very rich and proliferating consequences. Mathematical beauty is something that mathematicians can agree about, so I think it is a real property of science. And we have found time and again, in the more than 300-year history of modern theoretical physics, that it is only equations that have that character of mathematical beauty, which turn out to have the long-term fruitfulness of explanation, which persuades us that they are indeed telling us of a true aspect of the structure of the physical world. It's an actual technique in fundamental physics, to look for beautiful equations. The greatest theoretical physicist I've known personally, I think, was Paul Dirac, who was one of the founding figures of quantum theory, and he made his great discoveries by a lifelong and highly successful quest for mathematical beauty. In fact, he once said it was more important to have mathematical beauty in your equations than to have a fit experiment. He didn't mean by that, of course, that at the end of the day it didn't matter if your equations fit the experiment. No scientist could think that. But if they didn't appear to at first sight, well, maybe you hadn't solved them in the right way, maybe the experiments were wrong. There was some sort of residual hope. But in Dirac's view, if your equations were ugly, there was no hope. And Dirac had a brother-in-law, whose name was Eugene Wigner, and who also won a Nobel Prize for physics. And Wigner once said, why is mathematics so unreasonably effective? Why is this abstract subject the key to unlocking secrets of the physical universe? What links together the reason within the mathematical thoughts of our minds and the reason without the structure of the world around us? Now, I think it would be intellectually lazy simply to say, well, gee, that's the way it happens to be, and I bet a good luck for you chaps who are good at math. There's a very significant fact about the world, that science is possible, that mathematics is the key to unlocking the secrets of the universe, is unreasonably effective, and that sort of thing. So those are deep questions that we should seek to address. Now, when you ask a really deep question like that, there won't be a knock-down answer to it. But to me, the most intellectually satisfying and persuasive answer is that the reason within and the reason without fit together because they have a common origin in the mind of the creator, whose will is both the ground of our mental experience and of the physical world for which we are a part. You can summarize what I've been trying to say in the last five minutes or so by saying as science studies the universe in its rational transparency and rational beauty, it sees a world that is shot through with signs of mind. And I'm suggesting that you should consider seriously the possibility that it is the capital M mind of that world's creator that lies behind this wonderful order. In my view, science is possible because the world is a creation and, to use a powerful and ancient phrase, we are creatures made in the image of our creator. So that's my first sort of question. I want to just briefly ask a second question of a more specific character, and it's this. Why is the universe in which we live so special? Now, scientists don't like things to be special. Our natural instinct is to think that our universe is just a common or garden specimen of what a universe might be like. But the more we've come to understand the history of the universe, the more we've understood the processes which turned what was initially simply an almost uniform expanding ball of energy about the simplest physical system you could possibly think about into the home of saints and scientists today over a period of 13.7 billion years, as we understand many of those processes. We've seen that though, of course, that took time for them to happen, it was, as far as we know, 10 billion years before any form of life was in the universe, and self-conscious life like you or me only appeared yesterday in cosmic terms. Nevertheless, the universe was pregnant with those possibilities, essentially from the Big Bang onwards, because we live in a world that is very special, which is very fine-tuned to allow the possibility of the evolution of life. We don't live in any old world in that sort of way. That was a very surprising discovery, and none of us expected that. And there are many, many reasons that we have for believing that to be the case. I've just got a few minutes left as I say something to indicate at least one of the reasons why we think that's so. We are essentially carbon-based life. You need a lot of elements for life, about between 25 and 30 elements, but the key element that you need is carbon. Carbon is the basis of those long-chain molecules, which are the biochemical basis of life itself. Now, the very early universe, the first three minutes of its life, is so intensely energetic, so intensely hot, that it's a sort of cosmic hydrogen bomb. And nucleophases go on, but as it expands, it cools. And after about three minutes, it's frozen out with whatever it succeeded in making in those hectic first three minutes. And because it's very simple, it only makes simple things. In fact, the first three minutes essentially only make the two simplest chemical elements, which are hydrogen and helium. And they have a boring chemistry, and you can't do very much with them. So where does carbon come from? There's only one place in the whole universe where carbon is made. It is made in the interior nuclear furnaces of the stars. Every atom of carbon in your body was once inside a star. We have creatures of stardust made of the ashes of dead stars. As the universe expanded, it cooled down, but it also condensed into stars and galaxies. And as the stars heated up, these nuclear processes began. And one of the great achievements of the second half of the 20th century in astrophysics was to figure out the very delicate chain of processes by which carbon is made. And it is a very delicate and beautiful process. You see, you've got helium. Now, if you could... which in the trade we call helium-4. If you could make three helium-4s stick together, that would make carbon-12. But when you have things as small as nuclei, it's impossible to make three of them stick together at once. Okay, you see, we'll do it piecemeal. We'll do it bit by bit. That's two of them stick together. That would make beryllium-8. And maybe if that stays around for a bit, then from time to time, another helium will come along, attach itself, and bingo, we've got carbon-12. That's the obvious thing to think about. But it doesn't happen in the obvious way. And the reason it doesn't happen in the obvious way is that beryllium-8 is intentionally unstable. It just disappears before, in an ordinary sort of way, that third helium nucleus has a chance to attach. So how does it happen? Well, that problem was solved by a senior colleague of mine in Cambridge, Fred Hoyle. And Hoyle realised that if there was a resonance, that's to say a very, very large enhancement effect, in carbon occurring at exactly the right energy, then that attachment process would go much, much faster than you thought. In fact, so fast that it would occasionally catch that third helium. So you had to have that resonance, and you had to have it at the right energy. So he went off the nuclear data tables just to check up that the resonance was there, and it wasn't. But he was a very persistent chap and he had the bit between his teeth. And he rang up two American friends of his, a father and son team called the Laursens, who were very clever experimentalists, and he said, look, you chaps have missed something. There's an energy level in carbon that you haven't detected. And I can tell you exactly where to look for it, because I know what its energy must be. And they said, no, no, we're busy, we've got other things to do, we don't want to do that. But Fred was very determined, and he eventually bullied them into looking for it, and they found it. And that's a wonderful story. It's a wonderful scientific story, to predict an energy level in carbon on the basis of how carbon was made in the interior nuclear furnaces of stars is a fantastic scientific achievement. But Fred, who had a lifelong commitment to atheism, realised it was more than that. Because, of course, if the laws of nuclear physics had been a little bit different, a little bit stronger, a little bit weaker, either there would have been no resonance at all, or it would have been at the wrong energy. So somehow or other, the laws of physics in our world are finely tuned to permit the possibility of producing carbon, and so eventually of producing carbon-based life. And Fred was shaken by that. And he has reportedly said, in a Yorkshire accent that is beyond my powers, I'm afraid to imitate, the universe is a put-up job. This remarkable fine-tuning cannot just be a happy accident. Of course, if it wasn't so, we wouldn't be here, but it's too significant a fact just to shrug our shoulders and say, gee, that's the way it is. And Fred doesn't like the word God, so he said some capital-I Intelligence must have monkeyed with the laws of nature to make that possible. Now what that could possibly mean, I don't know, but as a religious believer, I would say that the universe is not any old world. It is a universe, it is a creation, which has been endowed by its creator with precocity, those fine-tuned laws and circumstances that label it to have a fruitful history. If you don't like that, and some people don't like that, then they're driven to the rather desperate recourse of supposing there are just trillions and trillions of different universes, all independent of each other, all unknown to us except our own one, and ours is just the winning ticket, because it's our happiness by chance to be so. That seems to me an extraordinary prodigal and unattractive thing. So that's another gift that, and there are many other things I could talk about in that area, but that's another gift that religion gives to science, not to tell science what to do in relation to its own questions, but to set its understanding of how the world is in a more profound and wider context of understanding. I mean, I'm here as somebody who wants to take absolutely seriously science and religion, and I'd like to say that I look at the world through two eyes. I look with the eye of science and I look with the eye of religion, and I believe that binocular vision enables me to see more and to understand more than either eye would on its own. Thank you very much. John, take us back to the moment where you were in an office at Cambridge University. You're a physicist. You have other members of the physics faculty there with you, and you've made some decisions, and they're about to leave your office, and you say to them, hold on. Yeah, wait a minute. I said, I've got something I want to tell you. I told them that I decided that I had done my bit for physics, and the time had come to do something else, and I was going to, in 18 months' time, because I had to wind up my academic affairs, 18 months' time, I was going to leave, resign my chair, train for the Anglican priesthood. And there was a sort of, well, rather stunned silence immediately followed that, and then one of my colleagues, with whom I'd done a lot of work, who is not himself a religious person, he said, John, I wouldn't have guessed you were going to do this if you told me you were leaving physics. I would have guessed this is what you were going to do. I found that a very supportive and kind thing to have said. Why would he say that? What drew that kind of a conclusion out of him about you? Well, I think everybody knew that religion was very important to me in my life. I mean, I wasn't rushing around putting tracks in people's pigeon holes, but I think they knew that, so they knew it was a serious component of my life. I mean, just think about this for a second, though. You helped explain the existence of quarks and gluons, the smallest known particle, and you want to leave that world and go be a priest in some village nobody's ever heard of. Didn't at any point you think I am committing intellectual suicide? Well, let me say, first of all, that in these mathematically based subjects, like theoretical physics, you don't get better as you get older. You... Wait a second. What does that mean? It means that though you probably don't do your best work before you're 25, by 45, and I've passed my 45th birthday, by 45 you've probably done what you can for your subject. Also, the subject was changing. The dust had settled, the quark model was now what's called the standard model, and the subject was changing, and it was becoming more speculative, string theory was around, and that wasn't so congenial to me. I mean, I didn't leave physics for a moment because I was disillusioned with it, but I just felt I'd done my bit for it and I'd do something else. I was a senior member of a very large and talented research group in Cambridge, and I didn't want to stay on beyond my sell-by date, so to speak. I didn't want people to... I didn't want... Your sell-by date? Is that what you just said? Well, I didn't want people to be saying behind my back, poor old John, he's not what he used to be. And I, to be very frank, I'd seen this happen elsewhere to older senior colleagues of mine, and I could see them getting a bit more miserable, not as they moved away from the subject, but the subject moved away from them. And I just decided I wouldn't allow that to happen to me. And I think it was the right thing to do. But did you hear any whispers in the coffee rooms or anything like that saying, oh, John, he's leaving this for the priesthood? Well, obviously, I mean, well, theoretical particle physics is a sort of international village, so the news spread around, the gossip spread around quite quickly. Obviously, quite a lot of people thought I was crazy, but quite a lot of people, and pretty many people who weren't at all religious believers were respectful of it. I mean, they could see that this was a thought-out and, for me, an important decision. So, by and large, the community was accepting and supportive, which I'm grateful. So, at no point you thought, I'm putting my brain on hold here to follow this? Well, I wouldn't say at no point, because, of course, in these big changes in life, you have your ups and downs. And there are times you wonder, you know, what am I doing? But I never felt truly repentant of it, so to speak. I never felt, gosh, I wish I'd never done that. And as I played myself into that new life, and I became a parish priest, that had its own satisfactions. I was also aware, of course, of the fact there were bits of me that weren't being exercised in parish life. I mean, the village I was a vicar of outside Canterbury was a very nice village, but it wasn't full of people wanting to talk either about science original or about particle physics. Really? People in your parish didn't want to talk about particle physics? One or two did, but not too many. So when I was actually in an unsought way offered the opportunity of returning to Cambridge to a job that was both partly academic and partly pastoral, to be the dean of chapel in one of the colleges there, that did seem to me the right thing to do, and so I came back into the academic world. By that time, I'd reached the conclusion, which, strangely enough, I hadn't thought of, first of all, that part of my continuing vocation was to think and write and speak about science and religion. Of course, getting back into the university world gave me more time and space to do that. What's harder, being a physics professor or a parish priest? Well, they're different. They're different. I mean, every profession has its hard aspects and its calling snare and all that sort of thing. There were two things that I missed in parish life, from academic life. One was the rhythm of term and vocation. I mean, term time is very busy, particularly in Oxford and Cambridge because our terms are short and so they're very intense. But then there's always the vocation coming, and the vocation, you have the chance to get on with your own work and that sort of thing. Parish life, of course, is 52 weeks a year. So I missed that. The other thing I missed, actually, was working with professional colleagues. Of course, we were working with people all the time, very nice people, and I'm grateful for what they did, but there's some sort of relationship with your professional colleagues where you can say, what do you think about Old Joe? What's going on there? In parish life, you have to be more discreet than that, obviously. And so I missed that as well, but that's the way it was. I'm thinking about this issue of being with colleagues at Cambridge University. You're around really smart people. Everybody in Cambridge is smart. Up to a point. Up to a point, I think. Don't you love the way he just kind of mumbles in a little thing? But you're out in this as a parish priest among people who don't have a very sophisticated sense of who God is or how the universe works. In fact, some of them, probably a lot of them, never asked the big questions, and you were surrounded at one point by people who were constantly asking big questions, and now you're not. Wasn't that a little tough? It was certainly different. I didn't feel it was my role to impose those questions on people unless they were exercised about them. If they were, and there always were some people around, I was obviously happy to talk to them. But the other side of it, the positive side of parish life, is you have the privilege of being with people, often the very important and determinative parts of their lives. Baptising recently born children, visiting people in hospital, taking people's funerals, marrying people, things like that. So there's a tremendous privileged access and opportunity for seeking to be confidentially helpful to people, which doesn't have as controversial in the academic world as anything like the same degree. I'm thinking one of the things that you probably have encountered over the years is people who would say, whether it was at your parish or in an academic setting or wherever, that they don't understand how you can believe in God. They clearly don't believe in God because all you have to do is look around you and look at all the suffering, look at cancer, look at hurricanes, look at earthquakes. How could you possibly be a representative of a God who allows that? Well, these are very serious problems. I think the most difficult problem for religious belief is the problem of suffering in the world. In a talk I gave earlier this afternoon, I suggested that science gives us some help in that. That it's not that God is careless or callous, but that there is an intrinsic cost in the fruitfulness of nature. Now, some people, nobody will find that completely existentially helpful. They won't say, well, that explains it all. Some people will find it partly helpful. It was a privilege to try and share that with people when it seemed appropriate, if they were able to hear that. You have also said that science and religion can be friends, not foes, and that was clearly the case in your upbringing. But I'm thinking of another scientist, E.O. Wilson, for instance. He was brought up in a Christian home and had Christian training and he goes to college and learns about science and says, this whole religion thing, what a crock! So, how come you two ended up differently, even though you had... Well, it's not within my power to explain the spiritual and intellectual biographies of anybody other than myself. So, I'm sorry that he's reached that conclusion. I mean, people are, I think, when they're young and impressionable, sometimes presented with misleading and unfavourable views, either religion or science, and it's then often very difficult to recover from that. But, as I say, it's not for me to offer interpretive accounts of how other people reach their views. I can speak for myself. What role, in your opinion, what role does mystery have for a scientist? Well, I won't just say for a scientist, but for anyone in general. I mean, I think the world is strange and surprising and we sometimes have to accept things which seem to us very mysterious. At the beginning of the 20th century, people realised that light not only behaves like a wave, spread out and flappy, but also like a particle, and that seems absurd, not so much mysterious as just absurd. How could that be? Now we understand that very well through something called quantum field theory. But for 25 years, the scientists had to hold on to experience without being able to reconcile these apparently disparate aspects of experience. That's a sort of scientific mystery for a while. I think there is bound to be an element of mystery in all theological talk, because science is easy in the sense that we transcend the physical world, we can put it to the test, we can manipulate it. God transcends us, we can't put God to the test. God is infinite reality and we are finite beings. So no human thought will ever totally be adequate to thinking about the divine nature. There's a strand in theological thinking which is called apathetic theology, stronger in the Eastern church than in the rationally confident Latin church of the West, which says that very often we can only know what God is not, than what God is. So we have to be cautious about that. And I think there is an irreducible amount of mystery in the divine nature. But the mystery card, in my view, is the last card to play, and not the first card to play. Why? Because we should seek to understand things as clearly and fully as possibly as we can. And we can only find out the scope of our understanding by exploring how far it can take us. Is it easier for a physicist to have this kind of thinking than maybe, let's say, a biologist or a chemist? Because what I'm thinking about is that no one has ever actually seen a quark, right? It's an unseen reality, yes, that's right. And in fact, some scientists say that we believe in quarks not because we have seen them, we believe in quarks because the equations that include them work. Yes, I mean, the belief in quarks explains a whole swathe of directly accessible experience. Makes sense of it, the patterns that are present in it. And therefore persuades us that these hidden quarks are lying behind this phenomenon. So is that why, would you say, then it's easier, if a physicist is already thinking that way, is it easier for a physicist then to have some sort of religious belief? Because that's also an unseen reality? Well, it might be. It certainly isn't foreign to a physicist to believe in unseen realities. For a physicist, it's intelligibility which is the key to reality. If quarks help us to understand the world, make sense of the world, that is an argument in favor of their existence. And I would want to argue that belief in God explains whole swathes of spiritual experience in an analogous sort of way. But also, physicists are deeply impressed with the wonderful order of the world. And so there is a certain, even among physicists who are not in any sense religious believers or attached to any particular religious tradition, there is a certain cosmic religiosity which comes naturally to them. Einstein used to like to say when he made his big discoveries, it felt like a child in the presence of the elders. There's some great mind behind all this. He was also absolutely emphatic that he didn't believe in a personal God at all. And of course, if he asserted for such belief, he was looking in the wrong direction. The impersonal world of science would never lead us to the concept of a personal God. If you're looking for that, you have to take the risk of engaging in a more personal form of encounter of reality. What would you say to someone who is raised in some sort of strict religious tradition and then starts taking science classes and feels like these science classes are actually contradicting what I was raised to believe. What do you tell that person? I think I want to say two things to them. I want to say that first of all that I believe that science is all for a truthful understanding. Those of us who are seeking to serve the God of truth should welcome truth from whatever source it comes. And therefore they shouldn't fear truth and they should be open-minded to see the insights that science is offering them. The other thing I want to say to them, it seems to me that people have a very fundamentalist, very anti-science sort of feeling about the world. In my view, it's a rather brittle position. And sometimes if that reduction of evolutionary biology somehow changes, they get convinced that there is a long history of life here on Earth, sometimes that can shatter the whole thing. But that's a scary experience, isn't it? It is, but I want to say to them that you don't have to give in to that experience. You don't have to feel that if you have to change your views about the origin of life and the character of life, that you have to throw away all your religious beliefs in which those previous beliefs were embedded. It's very important to think that it doesn't all go like shattering of a piece of glass. Well, let's flip it over then. What about someone who is raised in a very scientific kind of culture, and for whatever reason has some sort of a revelation of an unseen reality that they perceive to be God? What do you say to them, where they feel like my science is being challenged? Well, I wouldn't say to them that your science is not being challenged. What is being challenged is your scientism, the idea that science tells us everything, and anything that science doesn't tell us doesn't have a reality or significance about it. That's being challenged, and I think you should take whatever that fundamental experience was you had, you should take it very seriously and you should explore it and not just try to shrug it off. But it doesn't mean to say, equally it doesn't mean to say that you abandon your scientific understanding, but you simply recognise the limits of scientific understanding. Science only addresses a particular aspect of the world in which we live. I have heard you use the term motivated belief. What do you mean by that? What I mean by that is that one has reasons for beliefs. I mean, many of my scientific friends are wistful and wary about religion. They can see that many of them, even if they're not believers, many of them can see that science doesn't tell you everything. They can also see that religion offers you, potentially, a broader and a deeper view of things. But they fear that it offers it on unacceptable terms. The religious faith is intellectual suicide, shutting your eyes, gritting your teeth, believing impossible things because some unquestionable authority says that's what you've got to do. Of course they don't want to sit next to that, and nor do I. So I want to say to my scientific friends, I have motivations for my scientific beliefs, I have reasons for my scientific beliefs, reasons why I believe in the unique significance of Jesus Christ, reasons why I believe he was raised from the dead on the third day, and so on. If given the opportunity, I want to explain what some of those reasons were. They might not find those reasons sufficient, but they should at least know that they exist, that I'm not just a fideistic believer in the pejorative sense of the word. Somebody who just shuts their eyes and believes what they're told. But you've also said scientists have motivated beliefs. Of course, of course, yes. That's a less contentious thing, and less surprising to say, yes. So I have reasons for my scientific beliefs, I have reasons for my religious beliefs. There are different kinds of reasons, because there are different kinds of beliefs. But I want, either in science, or in religion, or in anything in between, because there is a spectrum of human encounter of reality in which there are two ends of the spectrum. I want to take motivating evidence seriously. I like to be what I call a bottom-up thinker. Bottom-up thinkers try to move from experience to understanding. Top-down thinkers start with general principles, clear and certain ideas, and condescend to dissent particulars. The trouble is that many of these clear and certain ideas have turned out to be neither clear nor certain. So I think it's better to be motivated by experience. Not, of course, solely one's own experience, but the reliably reported experience of others in seeking understanding of the world. All right. So here's my last question. I think you have a science joke, your favorite science joke, that you would like to share with us. Well, I don't think I... I... You warned me you were going to ask me a question about a joke, but I thought you were going to ask about a theological joke. No, no, no, no. Well, you can tell them both. I don't care, but I want the one about the hillside. Oh, yes, yes, yes. Thank you for reminding me. I'm here for you, John. Okay, well, here's my favorite scientific joke. There are three scientists who are traveling together through the Highlands of Scotland. One of them is a mathematician, one of them is a statistician, and one of them is a cosmologist. Now, they look out of the car, and on the hillside they see a black sheep. The cosmologist responds by saying all hills in Scotland have black sheep on them. Cosmologists generalize rapidly from particular experience. The statistician says there is a non-zero correlation between hills in Scotland and black sheep. The mathematician says there is at least one hill in Scotland on which there is at least one sheep, at least one of whose sides is black. Thank you for reminding me of that. All good jokes are serious jokes, and that does illustrate certain differences of intellectual discourse between different aspects of science. About two years ago, I was asked by a lady what was my favorite theological joke, and I couldn't on the spur of the moment think of what it was, or should be, rather. But again, it has to be a serious joke. It has to be a joke that has a point behind it. My favorite theological joke is one that you've probably heard preachers tell before, because it's quite a fair one. There's a man who is caught by a flood, and he has to go up to what you would call the second floor of his house. And he's looking out of the window, and a man comes along with a ladder and says, look, you climb down, and I'll carry you away from your house. And he says, no, no, no. God will look after me. I don't need that. So the man goes away. The waters continue to rise. Somebody comes in a boat. He says, come on, jump in the boat. I'll take you away. The man says, no, no, no. God will look after me. Eventually, he's up on the roof. Things are getting so desperate. A helicopter hovers overhead. No, no. I don't need that. God will look after me. He drowns. When he appears before the Lord, he says, look, Lord, why didn't you look after me? God says to him, I sent you a ladder. I sent you a boat. I sent you a helicopter. What more do you want? And, of course, the serious message is that God works as much through people as through any other way. John Polkinghorne, thank you very much for being here. Thank you.