Modern Physics, Ancient Faith: An Interview with Physicist Dr. Stephen Barr
by Brandon Vogt
Filed under Christianity and Science
Some news hooks are irresistible, even when they're false or at least incomplete. Case in point: the alleged conflict between science and religion. Is science opposed to religion? The answer depends in large measure on what you mean by religion. If your "religion" is, say, astrology, then you could say there's a conflict between science and "religion". The science of astronomy does conflict with the "religion" of astrology.
Probably most people who speak of a conflict between science and religion, though, don't mean the "religion" of astrology—if they think of astrology as a religion at all. They mean Christianity or perhaps Judeo-Christianity. They have before their minds Galileo and his struggle with the Inquisition of the Catholic Church over geocentrism or, more recently, the argument certain Christians have with the theory of evolution. Or perhaps they have only a vague idea that as science progresses religion becomes more and more problematic. Religion, in this view, is simply a way of talking about things science hasn't yet explained. When science gets around to explaining them, no role for religion will remain, and like the State in the Marxist paradise, it will wither away.
Those ideas about science and "religion" suppose an inherent conflict between the two fields. Conflicts, of course, make for more exciting news stories. But does the constant "hook" of a battle between science and religion reflect reality? Are science and religion—specifically Christianity—inevitably at odds with one another?
No, says physicist and Catholic Stephen Barr, author of Modern Physics and Ancient Faith (University of Notre Dame Press). Dr. Barr is professor of physics at the Bartol Research Institute at the University of Delaware. His writings include essays such as "A new Symmetry Breaking Pattern for SO(10) and Proton Decay" and "Electric Dipole Moment of the Electron and of the Neutron." He also contributes essays and reviews in First Things magazine, where he writes on such topics as evolution, Intelligent Design, and naturalism.
Dr. Barr recently agreed to answer some questions regarding science and religion.
Q: What is your background in science? In religion?
Dr. Barr: I received my Ph.D. in physics from Princeton in 1978. Since 1987 I have been a professor at the University of Delaware. My field of research is theoretical particle physics, and I have worked primarily in the area of "grand unified theories" and the cosmology of the early universe.
I am a lifelong Catholic.
Q: The controversial issue of Intelligent Design involves a basic question: What is science? How would you define science, as opposed to philosophy and theology? And would you call the "design hypothesis" put forward by the Intelligent Design movement science?
Dr. Barr: Science is sometimes divided into the "natural sciences" (astronomy, physics, chemistry, geology, biology) and the "human sciences" (like anthropology and psychology). The goal of the "natural sciences" is to understand the "natural order" of the physical universe. There are, of course, realities beyond the natural order and beyond the physical, but they lie outside the purview of natural science. Philosophy and theology have a much broader scope.
As I understand the "Intelligent Design movement", they are saying that certain biological phenomena can only be explained as miracles. They don't use that language, but that is in effect what they are saying. I firmly believe that miracles do happen. But a miracle, since it is something that contravenes the natural order, lies outside of natural science. I think it is quite legitimate to use scientific arguments and evidence to make out a case that some event is in fact miraculous. But that means that you have run up against the limits of what natural science can explain, and are invoking something beyond those limits. That is why I do not regard the ideas of the Intelligent Design movement as being hypotheses within natural science.
Let me put it this way. Science may show that a person turned water into wine, but that would be a miracle, not a new effect in the science of chemistry. Nor was the parting of the Red Sea a new effect in hydrodynamics. I am not sure that the "design hypothesis" is a part of biological science. That is not to say that it is wrong.
Q: Some scientists write as if they think that science can answer any question capable of being asked and answered. How would you respond?
Dr. Barr: It's absurd, and I wonder if anyone really believes it. I suspect that most of the people who write such things actually have all sorts of firmly held personal convictions that they could not prove by "scientific" demonstration.
There are many important questions about which natural science has nothing to say. Can science say whether murder is wrong? Or whether human beings have free will? Or whom a person should marry? Or whether a nation should go to war? Or what a man should live for or be ready to die for? And yet these are questions that not only can be answered but must be.
Q: What, in your view, is the most significant misunderstanding when it comes to religion and science?
Dr. Barr: Many atheists believe that all religion is at bottom either a pre-scientific attempt to understand natural phenomena through myth or an attempt to obtain worldly benefits through magic. And since they see science as the antithesis of myth and magic they cannot help but see all religion as antiscientific. Of course, such people have little understanding what true religion is all about.
Q: Do you know many scientists who are also religious believers?
Dr. Barr: Yes, quite a few. Indeed, I have about half a dozen friends in my own field who are devout Catholics. In fact, one of the real geniuses in my field (he would be ranked at or near the very top) is a practicing Catholic. However, in my experience most scientists are non-religious. That may have more to do with general cultural attitudes than with them being scientists. I have found as much atheism in humanities departments as in science departments.
Q: The science/religion debate operates on a number of levels. One is on the cosmic level—the existence of the universe. What can science tell us of the universe's origins? Are there limits to what science can say? What roles do philosophy and theology play in considering the question of the universe's origin?
Dr. Barr: One has to distinguish the question of the universe's beginning moments from the question of why there is a universe at all. In my view, science will never provide an answer to the latter question. As Stephen Hawking famously noted, all theoretical physics can do is give one a set of rules and equations that correctly describe the universe, but it cannot tell you why there is any universe for those equations to describe. He asked, "What breathes fire into the equations so that there is a universe for them describe?"
As far as the beginning moments of the universe go, science may eventually be able to describe what happened then. That is, when we know the fundamental laws of physics in their entirety—as I hope someday we will—it may well turn out that the opening events of the universe happened in accordance with those laws. In that sense, "the beginning" could have been "natural". However, that would not explain the "origin" of the universe in the deeper sense meant by "Creation".
Let me use an analogy. The first words of a play—say Hamlet—may obey the laws of English grammar. They may also fit into the rest of the plot in a natural way. In that sense, one might be able to give an "internal explanation" of those beginning words. However, that would not explain why there is a play. There is a play because there is a playwright. When we ask about the "origin" of the play, we are not asking about its first words, we are asking who wrote it and why. The origin of the universe is God.
Q: What do you think about efforts to develop a "Theory of Everything"?
Dr. Barr: I prefer to speak about a "Theory of Everything Physical". The goal of fundamental physics is to find the ultimate laws that govern all of physical reality. Most physicists, myself included, are convinced that such ultimate laws exist. There are good reasons to suspect that "superstring theory"—or what is now called "M-theory"—may be that ultimate theory. However, we are very far from being able to test it. In any event, to call any physics theory a "Theory of Everything" is to make the unwarranted—indeed false—assumption that everything is physical.
Q: What about the idea of multiple universes? Can we speak meaningfully of more than one "universe"?
Dr. Barr: As most people use the phrase, "multiple universes" is really a misnomer. What they usually really mean is that there is just one universe that is made up of many "domains" or regions, which are mutually inaccessible in practice—for example, because they are too far apart. The physical conditions in the various domains could be so different that they would appear superficially to have different physical laws. However, in all such scenarios it is assumed that the various domains actually all obey the same fundamental or ultimate laws. This "multiverse" idea is a perfectly sensible one. In fact, there are reasons to suspect that our universe may have such a domain structure.
Q: Stephen Hawking, in A Brief History of Time, talks about God and the mind of God. Yet he also seems to question whether there really is the need for a Creator in order to explain the existence of the cosmos. How do you see the matter? Is God a "necessary hypothesis"? Does science have anything to say about the question?
Dr. Barr: Hawking asked the right question when he wondered why there is a universe at all, but somehow he cannot accept the answer. The old question is, "Why is there something rather than nothing?" Science cannot answer that question, as Hawking (at least sometimes) realizes. I think his problem is that he doesn't see how the existence of God answers that question either. Part of the reason that many scientists are atheists is that they don't really understand what is meant by "God".
Anything whose existence is contingent (i.e. which could exist or not exist) cannot be the explanation of its own existence. It cannot, as it were, pull itself into being by its own bootstraps. As St. Augustine says in his Confessions, all created things cry out to us, "We did not make ourselves." Only God is uncreated, because God is a necessary being: He cannot not exist. It is of His very nature to exist. He said to Moses, "I AM WHO AM. ... Thus shalt thou say unto the children of Israel: 'I AM hath sent me unto you.'"
I think scientists like Hawking would be helped if they could imagine God as an infinite Mind that understands and knows all things and Who, indeed, "thought the world up". If all of reality is "intelligible" (an idea that would appeal to scientists), then it follows really that there is some Intellect capable of understanding it fully. If no such Intellect exists or could exist, in what sense is reality fully intelligible? We need to recover the idea of God as the Logos, i.e. God as Reason itself. I note that Pope Benedict stressed this throughout his papacy, especially in his speech at Regensburg. It is an idea of God that people who devote their lives to rational inquiry can appreciate.
Q: You've written about the creation/evolution/ intelligent design controversy. What is your understanding of the main issues in that debate? Where do you come down?
Dr. Barr: There are really two quite distinct debates going on. One is between so-called "Creationism" and Evolution. The other is between Darwinism and the "Intelligent Design movement".
The so-called Creationists—a specific movement within the broader group of people who simply believe in a Creator—deny that evolution happened. They are charging off an intellectual cliff. There is overwhelming and convergent evidence from many directions for the evolution of species. So it is embarrassing that this "Creationism" versus Evolution battle is still going on. Fortunately, it has never been a Catholic fight. The Catholic Church has never had an objection to the idea of the evolution of species of plants and animals. As far as the evolution of man goes, the Church has always insisted that the human soul, being spiritual, cannot be explained by, or be the product of, merely material processes, whether biological reproduction or biological evolution. The soul of each human being is directly conferred on him or her by God, as taught symbolically in Genesis 2:7. However, the Church never condemned the idea that the human body evolved from pre-existing organisms. The natural origin of the human body by evolution is no more a threat to anything we believe as Catholics than is the natural origin of each human body by sexual reproduction.
Evolution as a biological theory has never bothered the Church, though she has always vigorously rejected radical philosophical ideas that were offshoots of it.
The debate between "Intelligent Design" and Darwinism has to be taken more seriously. The self-styled Intelligent Design (or "ID") movement says that while evolution may have happened the Darwinian mechanism of natural selection acting on random genetic mutations is not adequate to explain it. In particular, the ID people point to the great complexity of life, especially at the cellular level. If they are right, that would be very interesting, as it would almost force one to invoke miraculous intervention by God to explain many of the facts of biology. It would give us a slam-dunk proof for the existence of God. I, for one, would be very happy about that.
But are they right in saying that the Darwinian mechanism is inadequate to explain biological complexity? Most biologists, including most of those who are devout Christian believers, doubt it very strongly. And even if the ID people are right, it will be virtually impossible to prove that they are right because they are asserting a negative. They are saying that no Darwinian explanation of certain complex structures will ever be forthcoming. Well, there may not exist such an explanation now, but there might exist one later. So, in practice, I don't see a slam-dunk proof for miraculous intervention in evolution as coming out of this movement.
Frankly, I don't see this debate as one in which Catholics, as Catholics, have any stake. The traditional arguments for the existence of God are much deeper and more reliable than the ones the ID movement is trying to make. The Catholic Church herself has taken no stance on this controversy. A 2004 document of the International Theological Commission, Communion and Stewardship, issued with the approval of then Cardinal Ratzinger (now Pope Emeritus Benedict XVI), said it was an interesting dispute that should be left to scientists to decide, since it could not be decided by theological arguments.
Q: Critics of evolution point to statements made by some evolutionists to the effect that life emerged by chance occurrences or "random mutations" and natural selection. The "randomness" thought to be involved critics take as undercutting a claim that life on earth is the result of the creative act of God. What is your view of the matter?
Dr. Barr: The idea that chance plays a role in events is in no way contrary to Catholic doctrine. St. Augustine in The City of God says that no one in this life "can escape being tossed about by chance and accident". St. Thomas Aquinas devoted a whole chapter of his Summa Contra Gentiles (Book 3 chapter 74) to defending the proposition that "Divine Providence does not exclude chance and accident." The Bible itself talks about chance: "Time and chance happen to them all" (Ecclesiastes 9:11).
Things are matters of chance from a certain point of view. From God's point of view everything is known from all eternity. As Proverbs 16:33 says, "The lot is cast into the lap, but the decision is wholly from the Lord."
In everyday life we talk about the probabilities of things happening, and we talk about chance events, and such talk in no way implies a denial that God is in charge of everything and foreknows everything.
Scientists use the concepts of chance, probability, and randomness in much the same way. In a reasonably well-defined mathematical sense, the motions of the air molecules in a room are "random". There is nothing necessarily atheistic in saying this.
Q: The SETI project seems predicated on the likelihood of extraterrestrial life. Do we have good scientific grounds for thinking such life exists? Would the existence of extraterrestrial life pose any special problems, in your view, to religion in general or Christianity in particular?
Dr. Barr: There are too many things we don't know for anyone to be able to say that extraterrestrial life "probably exists" or "probably doesn't". For one thing, we don't know how big the universe is. Given what we now know, it is not unlikely that it is infinitely large. (I have found that many people have the false impression that the Big Bang theory implies a universe of finite size. Actually, in the standard Big Bang theory the universe can be either finite in volume or infinite depending on the value of a certain parameter, called Omega, and whether it is bigger or smaller than 1. Present theory suggests that Omega is so close to 1 that it will be very hard, and probably impossible, to determine by observation whether it is larger or smaller than 1.) Even if the universe is of finite size, it is likely to be exponentially larger than the part we can observe with telescopes. In short, we cannot set any limit at present on how many stars and planets exist. It could be 10 to the 20th power, or 10 to the millionth power, or indeed infinite. That is all-important in deciding how likely it is that advanced life exists elsewhere.
However, if there is life elsewhere, there are strong reasons to suspect that it is so far away that we will never make contact with it. So many conditions have to be satisfied for a planet even to be habitable, that it seems probable that we are the only sentient beings in our galaxy.
I don't see why extraterrestrial life raises any problems at all for Catholic theology. God might have created free and rational beings in other parts of the universe. If so, they would have immortal souls. If they fell, Christ could have redeemed them. He could have redeemed them in the same way He redeemed us. If the Second Person of the Blessed Trinity can assume unto Himself a human nature, He can assume unto himself the nature of another kind of rational creature as well.
Q: You've written about the issue of artificial intelligence. Many scientists and technicians seem to think it only a matter of time before a genuinely artificial intelligence, capable of engaging in all the kinds of intellectual activities of human beings is created. What is your view?
Dr. Barr: I think they are wrong. I do not believe that the human intellect and will are reducible to the operations of a machine. There are philosophical arguments going back to Plato and Aristotle for the immateriality of the human intellect. And I think that there are very suggestive indications from both modern physics and mathematics that seem to dovetail with these philosophical arguments. I am thinking in particular of quantum theory in its traditional formulation and Goedel's Theorem in mathematics. There are some great scientists (like Sir Rudolf Peierls and Eugene Wigner) who argued on the basis of quantum theory that the human mind could not be explained by mere physics. And there are several eminent philosophers and mathematicians who believe that Goedel's Theorem shows that the human mind cannot be explained as a mere computer. I explain these arguments in the latter part of my book.
Q: What do you think of Nancey Murphy's non-reductive physicalism? (Assuming you've followed her discussion.)
Dr. Barr: I haven't followed her writings, but I know that there are many people who would argue that "spirit" is an "emergent" property of matter. I look askance at such theories. As far as I am concerned, to say that the spiritual is "physical" is reductive. "Non-reductive physicalism" sounds to me like a contradiction in terms.
While the spiritual can be incarnate in matter, it cannot emerge from matter. The spiritual powers of man (i.e., his intellect and will) cannot be explained as growing out of the natural potentialities of matter, in my view. As I argue in my book, matter cannot understand and the merely physical cannot have freedom. I think Pope John Paul II said the same thing when he claimed that between man and the lower animals there is an "ontological discontinuity". And I think that Pope Pius XII was saying the same thing when he insisted that the human spiritual soul cannot have evolved by material processes. And I think that Genesis 2:7 is saying the same thing in speaking of God "breathing" the soul into Adam.
There are a lot of people nowadays who are made uncomfortable by the idea of a human "spiritual soul". I am not one of them. I am happy to see that we in English-speaking countries now once more say at Mass "and with your spirit" and in the Domine non sum dignus "only say the word and my soul shall be healed". There has been too much embarrassment over the idea of the soul.
Q: Many scientists are outspoken when it comes to social issues. Does science, qua science, provide objective values and an ethical code that is in principle universal? Or do scientists get their ethical principles elsewhere, like the rest of us?
Dr. Barr: Even Richard Dawkins admits that science cannot provide us with the answers to moral questions. I frankly don't see how materialism can ground any objective morality. In fact, I think materialism leads logically to a denial of freedom of the will; and if there is no free will any talk of morality is utterly meaningless.
Q: Obviously, such things are beyond the power of strict prediction, but do you think it likely that we will see another Copernican revolution in thought that affects our worldview, including our theological worldview? If so, in what area of science do you think it likely this will occur?
Dr. Barr: Before answering that, let me say something about the past revolutions in scientific thought. It can be argued that the Copernican Revolution and Newtonian Revolution gave rise to a worldview that was in some tension with traditional Jewish and Christian theology. However, in my view, several of the "revolutions" in twentieth-century science have actually moved us back toward a view of the universe, of human beings, and of our place in the universe that is more consonant with traditional Jewish and Christian ideas than with materialism and atheism. In fact, that is what my book Modern Physics and Ancient Faith, is all about.
If there are future revolutions in thought that come from science, we should not assume that they will move us away from traditional theological positions. I expect them to move us closer.
In physics, the most likely revolution in thought, in my view, would concern our understanding of space and time. I don't think that would have any significant effect on theology, except on naive theologies that are already at odds with what we presently know about space and time (like "process theology"). The greatest blank areas on the map of science are in biology and in the understanding of mind. I don't think those blank areas will ever disappear altogether, since it is unlikely that man is capable of fully understanding himself.
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