What’s at Stake When We Debate God and Cosmology?

Robert B. Stewart

The heavens declare the glory of God;

the skies proclaim the work of his hands.

Day after day they pour forth speech;

night after night they reveal knowledge.

–Psalm 19:1–2

When I consider your heavens,

the work of your fingers,

the moon and the stars,

which you have set in place,

what is mankind that you are mindful of them,

human beings that you care for them?

–Psalm 8:3–4

What’s at stake when we debate God and Cosmology? That is an interesting and complicated question. It is more complicated than it might at first appear because different sorts of questions are asked in relation to these two subjects. What do I mean by this? I mean that although there is considerable debate among philosophers, especially philosophers that are theists, concerning the nature of God’s attributes, such as omniscience, omnipotence, necessity, simplicity, aseity, his relationship to time, and so on, there is much more debate concerning his existence. There is no debate that I know of among cosmologists as to whether or not the universe exists. There is, however, significant debate as to the nature of the universe: Is it eternal or did it have a beginning? Is it fine-tuned or does it only appear to be so? Is there only one universe or a very, very large number of universes that make up a universe ensemble? If there actually is a multiverse, what sort of multiverse is it?

Perhaps the reason that the questions asked are so different is because of the nature of the disciplines that are the primary ones engaged in academic research concerning them—philosophy and physics. Philosophers live in a world of arguments. Physicists live in a world of equations. One is couched in the language of logic while the other is couched in mathematical terms. Though there are intentional similarities between math and logic, they are not one and the same thing.

The Nature of Debates

Debates don’t solve intractable questions. If they did, we wouldn’t have elections after a series of political debates. Everyone would just agree on who the best candidate was. But this does not mean that they are unimportant. In fact, they can be very useful. They are, however, limited in that only two people are speaking to an issue, and sometimes, not speaking to the issue at all. (All too often in contemporary debates, rhetoric and mood trump reason.) Furthermore, determining who is most persuasive is, to some degree, a subjective decision. So, no debate is the final word on a matter.

Debates focus on specific issues. This means that other important issues will not be addressed. This cannot be helped—and focusing on one topic at a time is generally a positive thing to do. Of course, debates can present better arguments than a person has heard to that point, and in that way help one to have better reasons for one’s beliefs than they previously had. They can also challenge previously held beliefs, and perhaps, motivate one to reassess his or her beliefs, or motivate one to have better reasons for their beliefs. Or one may conclude that perhaps one should keep an open mind on an issue and do some more research on it. I doubt that a rational person would change his or her mind on an important matter simply on the basis of one debate, but a single debate could play an important role in what and why one believes what one believes, or even be the final decisive factor in one changing one’s position on a matter.

The Primary Question

The primary question in this book is this: Does the evidence of contemporary cosmology render God’s existence more probable than it would have been without it? William Lane Craig argues, “Yes, considerably so”; Sean Carroll answers, “No, not even close.” This is a question to be answered in terms of more or less, rather than true or false. Clearly, Craig believes that the statement “God exists” is true, while Carroll believes it to be false. But this is not a book that directly deals with the issue of God’s existence, but rather, with the likelihood of God’s existence in light of contemporary cosmology.

The case for God’s existence is a cumulative case. In other words, one must consider a whole range of issues, or data, and/or arguments, to arrive at a rational conclusion on the matter. There are arguments for and against God’s existence that appeal to scientific facts, historical facts, religious experience, moral intuitions, consciousness, free will, necessity, abstract objects, and a host of other matters. The focus of this book, like the conference from which it arose, is contemporary cosmology and its relevance when considering the likelihood of God’s existence.

Distractions and Dead Ends

One thing that both theists and non-theists sometimes do that is not helpful is to argue along the lines of “If I were God, . . .” I must confess to having done this myself. Simply put, there is something that just feels right about this, at least some of the time. The problem is that—and this is something that both theists and non-theists agree on—I’m not God. On the contrary, this does not mean that we can never know that God (or God as conceived by a particular religious tradition) would or wouldn’t do something—so long as we first establish this fact through argument, evidence, or exegesis. Putting forward an unsupported opinion about what God would do is not helpful. “It seems to me that God would do such and such,” or conversely, “I can’t imagine why God would do such and such,” just isn’t good enough.

Appeals to authority, likewise, fall short of establishing a position. Opinions of experts are not unimportant, but a lone opinion is just that—a lone opinion. I suspect that there is no opinion so strange that one cannot find some doctorate-holder to affirm it. Hopefully, “experts” have reasons to support their considered opinions. When such is the case, then there is something to examine and consider. Good reasons would include valid arguments, or evidences that are observable, and thus measurable, or theories that are falsifiable. Of course, “reason” and “reasons” are somewhat ambiguous terms. Depending on who is speaking, a reason may refer to a cause, an argument, some evidence that seems to point in a particular direction, an experiment that demonstrates a prediction that a scientific theory made, or a subjective mood that motivates one to believe in a particular way. Simply put, the psychology of belief is mysterious and human beings are unpredictable in their behavior. Still, all of the participants in this book believe that we can—and do—make rational decisions, though we disagree on some points on what rational people should believe in.

Another unproductive thing, in my view, is to argue that one is determined by his or her belief system or worldview to believe unreasonable things. Obviously, our worldviews do play a role in establishing the starting point from which we reason. They dictate, in some sense, our presuppositions. This is true for all of us. (Presuppositions are not just things that other people have.) But people can—and do—change their worldviews. In fact, this happens frequently. Who doesn’t know a Christian who used to be an atheist? Who doesn’t know a once-professing Christian who no longer believes in God? Evidence and argument are very persuasive.

Perhaps an example of the sort of dead end rhetoric I have in mind will be helpful. I sometimes hear statements that run something like this: most scientists are naturalists, and are thus motivated by their worldview to find a naturalistic explanation, however strained it may be. This is certainly possible. In fact, it probably is true of certain individual naturalists, just as it is also likely true that some Christians are motivated to hold a theistic explanation, however strained it might be. But is it true universally, or even of the majority, of either group? I think not.

This sort of appeal to motive or worldview determinism is neither charitable nor helpful. I certainly have not found it to be the case with the vast majority of the scientists I’ve known. In my experience, scientists, both theists and non-theists, have been among the most forthright scholars I have ever met. As a group, they are perhaps the least inclined segment of the academy to protect the status quo. In fact, in science, going against the grain is the way to get famous, make a lot of money, and be remembered after you’re dead. This does not mean that there are no academic power plays in science departments. But this sort of broad-brush dismissal of arguments that you disagree with is simply lazy and unhelpful.

The same could be said for philosophers and philosophy. Unique creative thought is recognized and rewarded. I have philosopher friends, both theists and non-theists, with whom I have disagreements. Overwhelmingly, my experience has been that we can discuss our differences soberly and thoughtfully, sharing our reasons with one another, and either change our opinions to some degree, or understand better the opposing position, or at the end of the day, at least agree to disagree agreeably. If I didn’t believe this, I would not be directing the Greer-Heard Point-Counterpoint Forum!^[1]

Issues

The vast majority of the important decisions in life are complex. The question of whether or not contemporary cosmology makes the existence of God more plausible than it would be otherwise is surely one of these questions. Therefore, there are preliminary questions to answer before one can arrive at a final conclusion.

If the universe had a beginning, that would—at first glance—seem to strengthen the case for God’s existence. William Lane Craig has argued forcefully for over 25 years that if something began to exist, then that thing has a cause.^[2] This proposition has great intuitive force. Our day-to-day experience bears that out. This claim also seems to be, at least for the most part, assumed by scientists. Simply put, a cause is an explanation, and scientists seek to find explanations for why observed phenomena are the way they are. So, if it is true that anything that begins to exist has a cause, and if the universe had a beginning, then the universe had a cause. What that cause might be may not be the sort of question that science alone can answer. But it would still be true that the universe has a cause.

Another issue to be addressed is whether the universe is fine-tuned for life, particularly human life, and if so, what does that imply? Everyone agrees that it appears to be. Had certain fundamental constants of nature, such as the mass of the electron, the strength of the weak and strong nuclear forces, the ratio of protons to electrons, the expansion rate of the universe, the speed of light, been even slightly different than they are, then human life would have been impossible.^[3] The name frequently associated with recognizing these constants is the “anthropic principle.” It is important to note that the anthropic principle is not a scientific finding, but rather, a philosophical implication of science. Furthermore, there is no single anthropic principle, and the differences in the implications of the different anthropic principles are great. Some see this as pointing in the direction of theism, while others say it is just the opposite. John Polkinghorne and Nicholas Beale list four possible explanations for this apparent fine-tuning:

Polkinghorne and Beale prefer option #1. Martin Rees and many others prefer option #3.

It seems, then, that the elephant in the living room is the idea of a multiverse. In 1980, Alan Guth proposed a model that addressed some lingering questions arising from the standard (Big Bang) model of cosmology. His solution was inflation. Inflation posits that in the very tiniest moment of time in the earliest period of the history of the universe, the universe or a very large portion of it exponentially increased in size prior to the continued expansion that cosmologists observe today. Guth’s model was widely seen as a breakthrough because it provided an answer for the horizon problem and the flatness problem—two questions that had been baffling cosmologists concerning the standard model. The horizon problem has to do with why the cosmic background radiation observed by Penzias and Wilson, which was one confirmation of Hubble’s theory that the universe was expanding, was unexpectedly so even throughout the universe, while the flatness problem has to do with unexpected findings concerning the geography of space-time, that is, why it is much less curved than expected. When a model provides an answer to two vexing problems, scientists will take that model very seriously. For that reason, a very large percentage of working cosmologists either assume an inflationary model or work in some respect or another in relation to some sort of inflationary model. Though inflation does not necessarily lead to a multiverse, most inflationary models do predict a multiverse. This is because inflation is not just thought to have taken place on this side of the Big Bang, that is, in the observable universe, but is also thought to be the force behind the Big Bang—the reason that there was a Big Bang in our observed universe in the first place. Inflationary multiverse models are believed by a significant number of cosmologists to explain the apparent beginning of the universe and the apparent fine-tuning of the fundamental constants of nature for life. The idea of an ensemble of inflationary bubble universes seems to be the one most often appealed to by contemporary cosmologists.

Still, the idea of a multiverse is generally greeted with suspicion, if not outright disdain by non-cosmologists. The question that is frequently raised is this: is this science or science fiction (or even science fantasy)? If science is that work which is done by scientists, then inflationary models that include multiple universes are indeed science and deserve to be taken very seriously. We should ask, however, exactly what sort of science it is. The answer, in a word, is: theoretical. It is not operational in the sense that petroleum engineering is repeatedly applied in an oil refinery. Frequently, theoretical science is not observational. Theoretical physicists refer to a number of entities that they have never seen, even entities whose direct effects are not observed. This does not mean that theoretical science cannot become observational science. Theoretical science can potentially become observational by making predictions that can be tested. Perhaps the most famous example of this was in 1919, when Arthur Eddington and his colleagues confirmed that some of the predictions of Einstein’s theory of General Relativity were correct.

A theory that makes predictions is far preferable to one that does not because a prediction can be tested and either falsified or confirmed. This idea of falsification is one of the most important of all concepts in the philosophy of science. Karl Popper held that the proper mark of a scientific theory is falsifiability. If a theory cannot be falsified, it is, according to Popper, a pseudo-scientific theory or a myth. He even insisted that science does not proceed by proving theories, but rather, by falsifying them.^[5]

This is a real problem for inflationary multiverse theories because they are, for the most part, not verifiable. By definition, another universe cannot be observed. Accordingly, physicist Lee Smolin laments the lack of confirmed predictions in contemporary physics.

New theories have been posited and explored, some in great detail, but none has been confirmed experimentally. And here’s the crux of the problem: In science, for a theory to be believed, it must make a new prediction—different from those made by previous theories—for an experiment not yet done. For the experiment to be meaningful, we must be able to get an answer that disagrees with that prediction. When this is the case, we say that a theory is falsifiable—vulnerable to being shown false. The theory also has to be confirmable; it must be possible to verify a new prediction that only this theory makes. Only when a theory has been tested and the results agree with the theory do we advance the theory to the ranks of true theories. The current crisis in particle physics springs from the fact that the theories that have gone beyond the standard model in the last thirty years fall into two categories. Some were falsifiable, and they were falsified. The rest are untested—either because they make no clean predictions or because the predictions they do make are not testable with current technology.^[6]

Furthermore, the most promising sorts of multiverse theories presently appeal to string theory or the more speculative superstring theory or M-theory. String theory, or some sort of string theory, may be the way forward and may indeed prove fruitful, but there are issues with all varieties of string theory. None is without its problems. The fundamental problems with string theory are that there is no consistent formulation of string theory and that string theory makes no real experimental predictions. Concerning the lack of consistent formulation, string theorist Brian Greene states it thus:

Even today, more than three decades after its initial articulation, most string practitioners believe we still don’t have a comprehensive answer to the rudimentary question, What is string theory? . . . [M]ost researchers feel that our current formulation of string theory still lacks the kind of core principle we find at the heart of other major advances.^[7]

Michio Kaku is straightforward in assessing the evidence for superstrings, “Not a shred of experimental evidence has been found to confirm . . . superstrings.”^[8]

Commenting on the not uncommon optimism that a final theory of everything was right around the corner, and particularly on M- and F-theory, Roger Penrose pessimistically declares:

From my own perspective, we are much farther from a “final theory” even than this. I have no faith at all that the developments outlined in Chapter 31 [Supersymmetry, supra-dimensionality, and strings] are at all close to the right lines. Various remarkable mathematical developments have indeed come out of string-theoretic (and related) ideas. However, I remain profoundly unconvinced that they are very much other than just striking pieces of mathematics albeit with some input from deep physical ideas.^[9]

John Polkinghorne notes that one prediction that the concept of inflation makes is “the existence of a particle called the inflaton, which has not been observed and whose mass, according to the principles of the standard model, should probably be such that it would be readily observable.”^[10]

In an influential 2014 article in Nature magazine George Ellis and Joe Silk urged both caution and methodological openness in what is accepted as science:

The consequences of overclaiming the significance of certain theories are profound—the scientific method is at stake. . . . To state that a theory is so good that its existence supplants the need for data and testing in our opinion risks misleading students and the public as to how science should be done and could open the door for pseudoscientists to claim that their ideas meet similar requirements.

What to do about it? Physicists, philosophers, and other scientists should hammer out a new narrative for the scientific method that can deal with the scope of modern physics. In our view, the issue boils down to clarifying one question: what potential observational or experimental evidence is there that would persuade you that the theory is wrong and lead you to abandoning it? If there is none, it is not a scientific theory.^[11]

In no way do I intend to argue that these are not serious scientific theories, but I do want to point out that they have obvious weaknesses that are apparent to both specialist and non-specialist. This does not mean that they will not eventually be proven correct, or at least, that a scientific consensus will develop, affirming them.

At the end of the day, an inflationary multiverse theory may best describe the state of the universe prior to the Big Bang and also account for the apparent fine-tuning of the observable universe. This would not necessarily mean either that the universe did not have a beginning or that the universe wasn’t fine-tuned.

In a recent article, Audrey Mithani and Alexander Vilenkin ask the question, “Did the universe have a beginning?” They discuss three cosmological models that “seem to allow the possibility that the universe could have existed forever with no initial singularity: eternal inflation, cyclic evolution, and the emergent universe.” They find each lacking, and conclude: “Did the universe have a beginning? At this point, it seems that the answer to this question is probably yes.” It is important to note that they use the term “beginning” as a synonym for “past incompleteness.” They do not imply that the evidence points to God.^[12] Leonard Susskind responded to Mithani and Vilenkin, and concluded that, “We may conclude that there is a beginning, but in any kind of inflating cosmology the odds strongly (infinitely) favor the beginning to be so far in the past that it is effectively at minus infinity.”^[13] Marcus Chown quotes Susskind as saying, “I find it a paradoxical situation to say that there must have been a beginning, but it is with certainty before any nameable time.”^[14] This is hardly a knock-down refutation.

So, if it is true that anything that begins to exist has a cause, and the universe had a beginning (however long ago), then the universe was caused. Theists are within their rights to ask whether or not this cause, which is clearly outside space-time and highly powerful, and quite possibly, personal and intelligent, might be God. Science cannot answer this question one way or another.

Similarly, an inflationary multiverse does not rule out anthropic fine-tuning. Polkinghorne and Beale write:

But we note that inflation, if it does occur, doesn’t eliminate the fine-tuning problem: to explain two observable parameters, it introduces a complicated theoretical mechanism with vast unobservable cosmological implications that itself needs at least two parameters to have the right values. At a fundamental level, the mystery remains.^[15]

Finally, while there are reasons to be skeptical about inflationary multiverse theories, some of the best minds on the planet are eagerly investigating these theories and many are optimistic that they will soon be confirmed. Will they or not? Who can say? If they are, then the scientific case for theism might be weakened a bit, although as we’ve seen, some who believe the best current theories are inflationary theories also believe that the universe had some sort of beginning. Clearly, if the universe did not have a beginning, then the scientific basis for theism is weakened. Still, there is no necessary philosophical or theological reason for theists to fear an inflationary multiverse. God, as conceived by theists, is incredibly (infinitely) powerful, intelligent, and creative. A multiverse would be in line with those attributes of God.

How Much Do We Really Know?

Lord Kelvin is reputed to have given an address to a group of physicists at the British Association for the Advancement of Science in 1900, in which he stated, “There is nothing new to be discovered in physics now. All that remains is more and more precise measurement.” I cannot find a primary source documenting this statement, though I have seen it in several textbooks, and it seems to be widely accepted. Albert Michelson wrote something similar in his book, Light Waves and Their Uses, “The more important fundamental laws and facts of physical science have all been discovered, and these are now so firmly established that the possibility of their ever being supplanted in consequence of new discoveries is exceedingly remote.”^[16] Looking back over the last century plus a decade, these statements seem either hopelessly naïve or utterly ridiculous. But at the time, they were accepted if not as facts, certainly as the opinions of the most knowledgeable scientists of their day.

We are no less creatures of our time than Kelvin and Michelson were of theirs. All scientific findings are provisional and subject to change. The last century has been a time of amazing scientific progress in general, and in cosmology in particular. We could make as much progress in the century to come, or maybe, even more. So, a dose of humility is certainly appropriate.

One reason for humility is that with every answer that we find, we also find new questions. The standard model was helpful, but it raised questions as to the fabric of space-time, and reflecting on those questions led to the discovery of several entities—whether observed or posited—that we don’t fully understand yet, nor are we likely to, without raising and answering questions that we have yet to learn need to be asked. My own view is that progress is always welcome and exciting, but that anyone who thinks that a “Grand Unifying Theory” will truly answer all cosmological questions needs to take a refresher course in the history of the universe.

How Much is Enough?

I am not a scientist. Neither am I a specialist in probability calculus. I am, however, the son of a judge. As such, I am well aware that there are different thresholds for evidence in different contexts. In a criminal case, to convict a defendant, a jury must believe that he or she is guilty beyond a reasonable doubt. Therefore, they must vote to acquit even if they think the defendant is probably guilty if there is, nevertheless, room for reasonable doubt. Such is not generally the case in a civil case. In most civil cases, a simple preponderance of the evidence will be enough for a guilty verdict to be handed down. Even if the jury has reasonable doubt as to the defendant’s guilt, they should still vote to convict if they think the defendant is probably guilty as charged.

At this present time, it seems that there are enough cosmological models that have no beginning to the universe or that feature enough universes to possibly explain away apparent anthropic coincidences to allow naturalists to retain their unbelief. It also appears that the standard model is still faring well enough for arguments such as William Lane Craig’s Kalām Cosmological Argument or some version of the anthropic coincidences to persuade many people that there is a God. No doubt, most of those who are so persuaded will have come to the evidence as theists. In short, those looking for a model of one sort or the other can always find one to suit their taste.

So, should we just retreat into our respective camps? I hope not. I suspect that for most people, science alone does not dictate whether they believe in God or not. As mentioned above, the case for God’s existence is a cumulative case. It is also true that for most atheists, the case for God’s non-existence is also a cumulative case, that is, their unbelief is not entirely based on science. Science may move the needle farther in one direction or another, but it is not the sole factor in most cases.

The question before us is this: does the evidence of contemporary cosmology render God’s existence more probable than it would have been without it? That little word “more” that comes before “probable” is important. The answer to that question may depend on who is assessing the evidence.

I wonder not if the evidence from contemporary cosmology renders God’s existence beyond reasonable doubt or even probable. I wonder if it renders it even a little more likely. Does it render it plausible enough to search in other ways to see whether God exists? Does it move the needle enough for someone who isn’t certain about God’s existence to search for God in the places and activities in which he reportedly is often found? Is it enough to prompt one to pray or to read the Bible or attend a worship service?

Some will object that it makes no sense to pray or to worship when they are uncertain of God’s existence. But these actions are surely not irrational, so long as one believes that God possibly exists and possibly will answer a prayer or reveal himself through Scripture or worship. Agnostic philosopher Anthony Kenny puts it this way:

There is no reason why someone who is in doubt about the existence of God should not pray for help and guidance on this topic as in other matters. Some find something comic in the idea of an agnostic praying to a God whose existence he doubts. It is surely no more unreasonable than the act of a man adrift in the ocean, trapped in a cave, or stranded on a mountainside, who cries for help though he may never be heard or fires a signal which may never be seen.^[17]

The question of God’s existence, or at least, the Christian God’s existence, cannot be settled by science alone. The nature of science does not allow for as much. But many will ponder over the question of God’s existence because of what science can tell us. Therefore, many will be uncertain. In my view, the proper response to uncertainty is further research, not pessimism. So, my suggestion to those who are uncertain is to continue to investigate with all the tools at their disposal, whether these tools are scientific, philosophical, historical, or theological.

I am making a suggestion of the same sort that Pascal makes in his wager. Though the wager may be understood in various ways, I am of the opinion that the wager is not an argument to believe that God exists, but an enticement to hope that God exists. Surely a man with a terminal disease is not behaving immorally to hope for a new surgical procedure to be developed that will save his life. Is a mother who has lost her three-year-old son irrational to at least hope that there is an afterlife and to seek to find the God who offers it, if he may be found?

I personally think that contemporary cosmology points in the direction of God’s existence, but I’m well aware that the final theory and experiment have not yet been devised, much less tested. I also recognize that not everyone will evaluate the evidence in the same way—and I don’t think that those who arrive at a different conclusion are necessarily behaving irrationally just because they disagree with me. I find the evidence powerful though my primary reason for believing in God is not scientific.

I hope that you will read this book with an open mind. I hope that you will read the entire book, not just the debate portion. The other authors are all serious scholars and gentlemen. I consider them all friends. They all have something important to say. And as a Christian, I encourage you to pray as you read. I know that not all of you will pray because some of you don’t believe in God. But what is there to fear? If he doesn’t exist, he won’t cause you to believe something that is false, and if you’re a rational person, you won’t begin to believe something that isn’t true just because you spoke to an imaginary being. Regardless, if you read this book with an open mind, I know you will be enriched.

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