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CHAPTER 1

Fact or Opinion?

Science is very impressive. We all benefit from its successes. I wouldn't be writing this book if the advances in medicine hadn't provided a means for me to survive a serious illness that struck twenty years ago. When I type up my scribblings, I use all the electronic wizardry of a sophisticated word processor. We all enjoy, every day of our lives, the new things made possible by the advance of science.

Science also enlightens our minds and enlarges our imaginations. We know that we are the inhabitants of an unremarkable planet, circling an unremarkable star, in a universe that contains at least ten thousand million million million stars. Once this universe looked very different from the way it does today, and it has had a long history, going back fourteen billion years to the fiery explosion of the Big Bang that gave it birth. Science tells us what makes the stars shine, why water is wet, how genetic information is conveyed from one generation to the next. It's a story of astonishing achievement, and perhaps the most impressive thing about it is that we can all agree on the answers it provides. The dust really does settle. Not only does science answer questions, it does so to universal satisfaction.

It would be foolish to deny that there's a striking contrast with religion. We'll not all agree on the answer to the most fundamental religious question of them all: "Is there a God?" Although the different faiths clearly refer to a common human experience of the spiritual, they seem to say such different things about it. Is the individual human self of unique value and significance (so say Judaism, Christianity, and Islam), is it, in fact, an illusion (so says Buddhism), or is it recycled through reincarnation (so says Hinduism)? Is suffering something to be accepted or avoided? And so on.

The conclusion seems clear. Science is based on facts and leads to real knowledge. Religion is just based on opinion. It may help you or me to live our lives — religion may be "true for me" or "true for you" — but it's not just plain "true," pure and simple. So it may seem, but I believe that such a conclusion would be a fundamental mistake of the most disastrous kind. If I thought it were true, I would not be a religious person. How could something really help one in one's life if it were just a personal illusion? Only the true can be a real basis for living — and facing death.

Two mistakes lead to the false conclusion that science and religion involve the encounter of fact with mere opinion. One is a mistake about science. The other is a mistake about religion. Let's take science first.

Many people's impression of how science progresses is that a prediction is made ("adding factor X will turn the liquid green"), an experiment is performed (it does turn green), and a great new discovery has been made. In actual fact, it is all a good deal more subtle and more interesting than that. In the first case, the facts that concern scientists are already interpreted facts. Most of the time you can't see directly what's happening. You have to infer it from the things you can see, and that inference requires the use of theoretical interpretation.

It's quite hard to give an example of this for the nonscientist because modern apparatus is so complicated and technical, exactly illustrating my point that you have to know the theory in order to understand the experiment. Rather than a "gee-whizz" discussion of electronic gadgetry, let me show you a picture. It's meant to represent a photograph of tracks in a device widely used for many years in my old subject of elementary particle physics (the study of the smallest bits of matter). The apparatus is called a bubble chamber. It contains a liquid that is just about to boil. A particle passing through triggers a chain of little bubbles, which make its path visible. It's a bit like bubbles rising in a glass of beer, and, in fact, the man who invented the device is said to have got the idea while brooding on his lunchtime drink. A photograph of a bubble chamber will show lots of these tracks, a complicated pattern of curls and swirls. Figure 1 on the following page is a simplified example of this.

Doubtless we could all painstakingly follow each track and agree on what sort of shape it had, but this, by itself, would be of no scientific interest whatsoever. The patterns only become significant when they're interpreted as indicating such-and-such a particle moving with such-and-such a speed and being made to curl around by the strong magnetic field applied to the chamber. Then it all becomes meaningful and interesting. I remember once being shown a particular photograph that, when its significance was explained by the experimentalists, turned out to show the existence of an entirely new particle. This was really exciting. Without the interpretation, it was just a mess.

Now the problem is this. In order to make the interpretation, you have to know some science already. You can't just stare at the world; you have to view it from a chosen point of view. Choosing the point of view involves an act of intellectual daring in betting that things might be this way. This means that in science, experiment and theory, fact and interpretation, are always mixed up with each other. They're as inseparable as the meaning and the ink that together make up the words of this book. Someone once said that scientists wear "spectacles behind the eyes" — it's not just what they see but the way that they see it that counts. In other words, science uses a mixture of fact and opinion. Of course there are reasons for the opinions, and opinions can be revised when they don't seem to work very well, but you can't do without them.

There's another reason why this is so that I haven't mentioned so far. In a bubble chamber photograph, there are likely to be some tracks that have nothing to do with the experiment, but are accidental strays, coming, perhaps, from the cosmic rays that continually bombard the Earth from outer space (in my figure, this is probably what the horizontal lines are, the really significant bit being the V at the bottom). In order to interpret what is happening correctly, it is necessary to identify and eliminate these spurious contributions. In the trade, this is called the problem of the "background." There is no rule book you can consult to tell you how to strain out these unwanted additional effects. It's a matter of judgement, and so, ultimately, of informed opinion, that this has been accomplished successfully. I could tell you some horror stories of incorrect conclusions that were reached because of errors made about background effects.

The idea that strange effects may be due to unexpected background can also lead to splendid successes. When the planet Uranus was discovered in the eighteenth century, astronomers found that it was not moving through the heavens in the way that Newton's theory of gravity predicted, but his theory was far too beautiful and far too effective to be abandoned without a struggle. Two mathematicians — Adams in England and Leverrier in France — independently hit upon the brilliant idea that the trouble might be due to the unseen presence of yet another planet, beyond Uranus. They were both able to calculate where it should be. I regret to say that the British astronomers were either too lazy or too incredulous to bother to take a look to see if Adams was right, so that the honor of discovering Neptune fell to the Continent. The moral of this little tale is that trouble in fitting the "facts" does not instantly disprove a scientific theory. It may just mean that more is going on than we had first appreciated.

The need to mix fact and interpretation, to survey the world from a chosen point of view, makes science more daring, and more precarious, than people often realize. Some philosophers have been so struck with this that they've gone on to deny that science can give us any reliable knowledge of how things actually are. Perhaps it's not discovery at all, but just an unconscious agreement among the scientists to see it this way. This extreme form of what is commonly called postmodernism alleges scientific theories to be no more than opinions adopted by an invisible college of like-minded people. Of course, such philosophers don't deny that science scores successes in getting things done, but they do suggest that this is all that science is up to — it's a collection of technologically useful manners of speaking. A road map is handy in helping one get from A to B, but we don't believe that motorways are thin blue lines or towns are thick black dots.

But wait a minute! Although a map is not the whole truth about the countryside, unless it represented at least part of the truth, it wouldn't work at all. That's what I believe about science. It never succeeds in telling us the whole truth about the physical world — there are always new things to find out — but, surely, it tells us some of the truth. We may not know all there is to know about atoms or electrons, but surely there are atoms and electrons. Science makes maps of the physical world that are reliable for some, but not every, purpose.

I believe this about science for three reasons. The first is one I've already hinted at. It seems impossible to believe that science could have been as successful as it has been unless it really did represent aspects of the way things are. Take the idea of electrons, the smallest particles of matter whose movement makes electric currents flow. We can also use them to understand how chemistry works, to make electron microscopes powerful enough to "see" atoms, to construct electronic devices of all kinds, and to do many more things besides. How could we manage all this unless there really were electrons with the kinds of properties we've discovered? To most people, this will seem obvious. I think the philosophers should agree with them.

Another reason why we should believe that science tells us what the world is like, is that it often turns out to be entirely different from what we expected. The physical world imposes itself on us as having its own nature, which we discover but in no way invent. Let me give you an example. One of the questions that perplexed scientists from the earliest days was "What is the nature of light?" Newton rather cautiously speculated that it might be made of little bullets. His Dutch contemporary, Huyghens, felt that it was more likely to consist of waves. In the nineteenth century, it seemed that the matter had been settled. Thomas Young (who also helped decipher Egyptian hieroglyphics) did some pretty experiments that showed some absolutely typical wave effects. Waves add together in different ways according to whether they are in step or not. If they are, two crests come together and reinforce each other; if they are not, a crest and a trough can coincide and cancel each other out. One effect brightens the light, the other darkens it. Young found that this variation of light and darkness did indeed happen. Later in the century, in one of the most brilliant discoveries of all time in physics, James Clerk Maxwell identified light as waves of electromagnetic energy. The question seemed settled in a most conclusive and satisfactory way. Imagine everyone's astonishment (and unease) when, in the early years of this century, Max Planck and Albert Einstein showed that, in some circumstances, light behaved, not as waves, but as bullets! I'll say some more about this later, but, for the moment, notice two things: first, no one wanted to believe that light was sometimes bullet-like, they were driven to it by the way things are; and, second, even when we think we understand the physical world pretty well, looking at it more closely may show that it still has surprises in store for us.

My final reason for believing that science is about the way things are is that what scientists really want to do is not to get things done by inventing clever devices, but to understand what the physical world is actually like. Let me tell you a parable to make this point. One day, a big black box is delivered at the Meteorological Office. With it comes an instruction booklet that reads "Feed in the details of today's weather at slot A, turn the handle, and out from slot B will come a prediction of the weather in a week's time!" It seems pretty unlikely, but they're an open-minded lot at the Met Office so they give it a go. Lo and behold, it works! Time and again the predictions are found to be correct. If the Met Office is simply about weather forecasting, simply about getting things done, its task is fully accomplished, but do you think those meteorologists would all pack up and go home? Not a bit of it. They don't want just to predict the weather, they want to understand how it arises from the interaction between the Earth's seas, land masses, and atmosphere. Within a few weeks, they would be tampering with the seals on that black box in an endeavor to understand why it was able to model the behavior of weather systems so perfectly.

You may be feeling a bit impatient. I've spent some pages defending the idea that science tells us what the physical world is like. Most people think this is obvious. I certainly think it's true, but, because science is really rather subtle in the way it works, I don't think it is obvious. It was worth looking at the question in detail because science's successful mixture of fact and opinion tells us something about how we get knowledge, and this may prove helpful in other spheres as well. It's time to take a look at religion.

Everyone knows that religion involves faith. Many people seem to think that faith involves shutting one's eyes, gritting one's teeth, and believing six impossible things before breakfast, because the Bible or the Pope or some other unquestionable authority tells us so. Not at all! Faith may involve a leap, but it's a leap into the light, not the dark. The aim of the religious quest, like that of the scientific quest, is to seek motivated belief about what is the case. We have already said that religion can only be of real value if it's actually true. It's not a technique for whistling in the dark to keep our spirits up.

When I decided that I'd done my little bit for science, and the time had come for me to do something else (in fact, become a clergyman), I had an interesting period of eighteen months or so during which I was winding up my academic affairs. I couldn't just leave my research students, saying "Cheerio, I hope you get a Ph.D."

During this period I had a number of interesting conversations with my colleagues in the international intellectual "village" that was the community of theoretical high energy physicists. "John, what are you up to?" they would say. Usually they were asking the more basic question of why I was a Christian, rather than the vocational question of why I had decided to turn my collar around. Over a cup of coffee in some laboratory canteen, I would try to explain my Christian belief. I knew that I had to do so by appealing to evidence. "What makes you think this might be true?" was the question to which I had to reply. In a half-hour conversation, it was scarcely possible to do more than make a few simple points (I'd have been similarly constrained if I'd been trying to convey to a nonscientist the reasons for my belief in quarks and gluons as constituents of matter). There was quite a complicated structure of interlocking experience and insight that had to be gone over in order to give a full explanation. In the end, I wrote a little book with a grandiose title, The Way the World Is (1992), setting out the reasons for my Christian faith as I would have done if I'd had several hours at my disposal to tell the story.

I don't want to repeat this exercise here. All I want to do is emphasize that there was a whole string of evidential questions to be addressed. How reliable is the New Testament? What can we actually know about Jesus? Are there reasons for believing the claims that he was raised from the dead? What are we to make of that strange phenomenon, the Christian Church, that has given rise both to St. Francis and the Inquisition? For faith to be possible, rational responses to these questions are required.

I believe that science and religion are intellectual cousins under the skin. Both are searching for motivated belief. Neither can claim absolutely certain knowledge, for each must base its conclusions on an interplay between interpretation and experience. In consequence, both must be open to the possibility of correction. Neither deals simply with pure fact or with mere opinion. They are both part of the great human endeavor to understand.

(Continues…)

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Excerpted from "Quarks, Chaos & Christianity"
by .
Copyright © 2005 John Polkinghorne.
Excerpted by permission of The Crossroad Publishing Company.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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