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present in carbon that would produce an enhanced effect. That is, it would make things go much, much more quickly than you would expect. However, you not only had to have a resonance but also had to have it at the right place; it had to be at the right energy for this process to be possible. If it were anywhere else, it would not affect the rate at which things happen.

      So, Fred is convinced that there must be a resonance in carbon at precisely this energy and writes down what the energy is. The next thing, he goes to the nuclear data tables to see if carbon had such resonance, and it is not in the nuclear data tables. Fred is so sure it must be there that he rings up his friends the Laurences, who are very clever experimentalists at Caltech, and says to them, “You look. You missed the resonancy in carbon-12, and I’ll tell you exactly where to look for it. Look at this energy, and you’ll find it.” And they did— a very staggering scientific achievement. It was a very, very great thing, but the point is this: That resonance would not be there at that absolutely unique and vital energy if the laws of nuclear physics were in the smallest degree different from what they actually are in our universe.

      When Fred saw that and realized that— Fred has always been powerfully inclined toward atheism— he said, in a Yorkshire accent, which, I am afraid, is beyond my powers to imitate, “The universe is a put-up job.” In other words, this cannot be just a haphazard accident. There must be something lying behind this. And, of course, Fred does not like the word God; he said there must be some capital-I Intelligence behind what is going on in the world. So, there we are; we are all creatures of stardust. Every atom of our bodies was once inside a star, and that is possible because the laws of nuclear physics are what they are and not anything else.

      Let me give you just one more example of fine-tuning. This is the most exacting example of all. It is possible to think of there being a sort of energy present in the universe, which is associated simply with space itself, and that energy these days is usually called dark energy. It used to be called the cosmological constant, but it has come to be called dark energy, because just recently astronomers believe they have measured the presence of this dark energy. In fact, it is driving the expansion of the universe.

      What is striking about that expansion is that this energy is very, very small, compared to what you would expect its natural value to be. You can figure out— now, I won’t go into the details— what you would expect the natural value of this energy to be. If you’re in the trade, it is due to vacuum effects and things of that nature, but it turns out that the observed dark energy— if the observations are correct— is ten to the minus-120 times the natural expected value (10^-120); that’s one over one followed by 120 zeroes.

      Even if you’re not a mathematician, I am sure that you can see that is a very small number indeed. If that number were not actually as small as it is, we would not be here to be astonished at it, because anything bigger than that would have blown the universe apart so quickly that no interesting things could have happened. You would have become too diluted for anything as interesting as life to be possible.

      So, there are all these sorts of fine-tunings present in the world. All scientists would agree about those facts. Where the disagreements come, of course, is in answering the meta-question: What do we make of that? What do we think about the remarkable character of the world, the specific character of the world? Was Fred right to think that the universe is, indeed, a put-up job and that there is some sort of Intelligence behind it all?

      I am sure you all know that these considerations about the fine-tuning of the universe are called the anthropic principle— not meaning that the world is tuned to produce literally Homo sapiens, but anthropoi, meaning beings of our self-conscious complexity. I have a friend who thinks about these things and has written, I think, the best book about the anthropic principle, Universes. His name is John Leslie. He’s an interesting chap because he does his philosophy by telling stories, which is very nice. He’s a parabolic philosopher. That is very nice for chaps like me who are not trained in philosophy, because everybody can appreciate a story, and he tells the following story:

      You’re about to be executed. You are tied to the stake, your eyes are bandaged, and the rifles of ten highly trained marksmen are leveled at your chest. The officer gives the order to fire, the shots ring out, and you find that you have survived. So, what do you do? Do you just walk away and say, “Gee, that was a close one”? I don’t think so. So remarkable an occurrence demands some sort of explanation, and Leslie suggests that there are really only two rational explanations for your good fortune.

      One is this: Maybe there are many, many, many executions taking place today. Even the best of marksmen occasionally miss, and you happen to be in the one where they all miss. There have to be an awful lot of executions taking place today for that to be a workable explanation, but if there are enough, then it is a rational possibility. There is, of course, another possible explanation: Maybe there is only one execution scheduled for today, namely yours, but more was going on in that event than you are aware of. The marksmen are on your side, and they missed by design.

      You see how that charming story translates into thinking about the anthropic fine-tuning— the special character of the universe in which we live. First of all, we should look for an explanation of it. Now, of course, obviously, if the universe was not finely tuned for carbon-based life, we, carbon-based life, would not be here to think about it. But the coincidence is that the fine-tunings required are so specific and so remarkable that it is no more sensible for us to say, “We’re here because we’re here, and there’s nothing more to talk about it,” than it would be for that chap who missed being executed to say, “Gee, that was a close one.” So, we should look for an explanation.

      Basically, there are two possible explanations. One is that maybe there are just many, many, many different universes— all with different laws of nature, different kinds of forces, different strengths of forces, and so on. If there are enough of those universes— and there would have to be a lot of them, an enormous number of them— but if there are enough of them, then, of course, by chance, one of them will be suitable for carbon-based life. It will be the winning ticket in the cosmic lottery, as you might say, and that, of course, is the one in which we live, because we are carbon-based life. That would be a many-universes explanation.

      Of course, there is another possibility. Maybe there is only one universe that is the way it is, because it is not just any old world but is a creation that is being endowed by its Creator with precisely the finely tuned laws and circumstances that will allow it to have a fruitful history.

      So, many, many, many universes or design, a created design. Which shall we choose? Leslie says we don’t know which one to choose. It is six of one and half a dozen of the other. I think in relation to what I have just been talking about— these anthropic fine-tunings— that Leslie is right about that. Both suggestions are what you might call metaphysical. Sometimes, people try to dress the many universes all up in scientific vestment, but essentially I think it is a metaphysical guess. We do not have direct experience of those many, many, many universes. That is a sort of metaphysical guess, just as the existence of a Creator God is a sort of metaphysical guess. So, what should we choose?

      If that is the only thing we are thinking about, we can choose one or the other with equal plausibility, but if we widen the argument, then I think we shall see that the assumption that there are many, many, many universes does only one piece of explanatory work. The only thing it explains is to explain away the particularity of our observed and experienced universe. The piece of work is to diffuse the threat of theism, but the theistic explanation— it does seem to me— does a number of other pieces of work.

      I have already suggested that a theistic view of the world explains the deep intelligibility of the world that science experiences and exploits, and I also believe, of course, that there is a whole swath of religious experience of the human-testified encounter with the reality of the sacred, which is also explained by the belief in the existence of God. So, it seems to me, there is a cumulative case for theism in which the anthropic argument can play one part, but only one part. It will not, of course, surprise you, given what you know about me, that it is that latter explanation which I myself embrace.

      There we are. That is one

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