I went to a debate recently in New York, between a rabbi and the famous polemicist Christopher Hitchens, on the question “Does God exist?” Hitchens was called on to speak first, and he won the debate with his first two sentences: “I don’t know why I have to speak first. He has the burden of proof.” The mostly secular New York audience heartily applauded this sally, which was based on the premise—never challenged by the rabbi—that science provides an explanation of everything and any need there might be for a Supreme Being is more an artifact of human psychology than anything else.

But it turns out that this premise is false; science has no explanation for any of the major questions about our existence, the existence of the universe, or even the nature of reality. What’s more, by the standards of science itself—the view that if something can’t be falsified it cannot be the subject of scientific inquiry—science will never be able to provide an answer to these questions.

Under these circumstances, it is just as rational to believe in the existence of a Supreme Being as it is to believe a Supreme Being does not exist. Since science will never be able to provide answers to the deepest spiritual questions, and the Supreme Being has not appeared to mankind in a way that all of us will accept, the most rational position is to describe oneself as an agnostic—a person who just does not know. One of the results of the Enlightenment was a broad recognition that squabbling about the correctness of this or that religion was pointless and counterproductive. In this sense, the Enlightenment has not yet come to those who relentlessly pursue the culture war between believers and nonbelievers.

Under the circumstances, it is just as rational to believe in the existence of a Supreme Being as it is to believe a Supreme Being does not exist.

Before exploring why this is true—why science does not and never will have the answers to the deepest spiritual questions—it’s important to distinguish between religion and a belief in the existence of a Supreme Being. In most cases, religion posits a God who intercedes in human affairs. There are, it is said, no atheists in foxholes. It may or may not be true that God has his eye on the sparrow as well as on individual human beings, but that is not what I am concerned with here. I simply want to make clear to those who call themselves atheists—even boastfully, at times, as though it is a badge of their intelligence—that they may in fact be more ignorant than those they disparage as benighted believers in spirituality. At least people of faith have made a decision based on something that gives them personal comfort, while the atheist has simply remained ignorant of basic facts that would call his atheism into question.

Let’s begin with the universe. Everyone knows about the Big Bang, the event that scientists believe involved the expansion of an unimaginably dense point, or singularity, into a universe so vast that the portions we can see with radio or optical telescopes are only a small part of the whole. I am not going to ask the obvious question: what existed before the Big Bang? That’s really not an interesting question. Maybe nothing existed. Maybe a predecessor universe existed. A believer in a supreme being would say that the universe was simply created by that being; an atheist would say that there might be many universes—which are always being created out of the void—and we happen to live in one of them.

But that’s where the interesting questions begin. The fact that we live in this universe is not something to take for granted. We are alive—that is, we believe we experience reality—because the universe we live in is based on a number of fundamental physical constants without which it would not be hospitable to life or would not exist at all. These fundamental constants of nature, such as the size of the attractive force of gravity, are essentially arbitrary; there is no law that requires them to be the way they are. Thus, as cosmologists will point out, if gravity were only slightly stronger, the universe would have contracted back into a singularity long ago, and of course life would not have developed. Similarly, if gravity were only slightly weaker, the stars and planets would not have formed and there would be no place for life. There are literally dozens of these foundational but arbitrary constants of nature without which life could not exist, ranging from the strength of the force that holds the nucleus of the atom together to the extraordinary fact that water in its solid form (ice) is lighter than it is in its liquid form, which is why the oceans do not freeze from the bottom up. The likelihood that all these relationships would exist at the same time is so extraordinary that one scientist has compared it to the chance that a tornado roaring through a junkyard would assemble a 747.

Scientists studying quantum mechanics have shown, beyond any doubt, that the objective reality we perceive around us is an illusion.

For obvious reasons, many “intelligent design” advocates see this set of extraordinary conditions—the “just so” universe that is necessary to support life as we know it—as confirmation that a supreme being is in charge. But this is not necessarily so. Some scientists argue that there could be other explanations: perhaps there is some undiscovered law of nature that dictates why all these constants must be the way they are; or perhaps there are (or have been) an infinite number of universes, and we are living in the only one that happens to have the necessary elements to make life possible.

This is where the debate is really joined. If we conclude that there is some undiscovered law that accounts for all these constants, or there is a “multiverse” of universes, how could our claim ever be falsified? This is not a small point. The scientific method involves explaining a state of facts by an initial hypothesis, experimental testing of the hypothesis, further development into a theory, and the temporary acceptance of a theory until it or any portion is shown to be wrong. If there is no way to prove or disprove, say, the existence of another universe, how is this belief any different from a matter of faith?

What we have, then, in this great culture war between the believers and the secularists are two different kinds of faith. The believers in a Supreme Being have their faith (a belief in a Supreme Being) and the secularists have theirs (a belief that science has the answers). There is no basis, however, for saying that either one is more valid than the other. 

Accordingly, when Christopher Hitchens said in the New York debate that the rabbi has the burden of proof, he was wrong (perhaps he has not looked into the science). The atheists also have to prove their case, though, ironically, they will not be able to do it through the scientific method. The existence of other universes, for example, can neither be proven nor falsified. So the atheist can never prove his point.

There is one respect in which the rabbi and other believers may actually have a stronger science-based argument than the secularists, and that is with respect to the nature of reality. Scientists studying quantum mechanics have shown, beyond any doubt, that the objective reality we perceive around us is an illusion. Exhaustive tests have shown that whether a proton, an electron, or a photon is in a particular place at a particular time is simply a matter of whether it is observed. Before it is observed, it has no fixed position; it is a wave and not a particle. It only becomes “real,” in the sense that it has a fixed position, when it is observed—when, for example, a test is run to determine its position. In other words, the building blocks of everything we see around us, including ourselves, cannot be said to have any objective reality until, in some mysterious way, they are changed from waves to the particles that have a fixed position and make up physical reality.

When we look at the culture war between the secularists and the believers, it is difficult to pronounce judgment in favor of either.

Albert Einstein, for one, refused to believe this could be true, and he spent the latter part of his life—after the development of general relativity—attempting to prove, as he put it, that “God does not play dice.” But neither he nor any other scientist has been able to counter the results of experiments that question the existence of objective reality. 

Moreover, at the quantum level there are connections between those elementary particles that cannot be accounted for by any theory. In a famous experiment, it was shown that two photons (the carriers of the electromagnetic force) that start out from the same place remain “entangled”—connected in some mysterious way—even when they are miles apart. This has been shown by manipulating one of them and finding that the other changes simultaneously. There is no scientific theory that explains how this could happen, and it remains a mystery, especially because the simultaneity violates the principle that no signal (at least in this universe) can travel faster than the speed of light. But for the believer this would not be such a mystery, since one way to conceive of the universe is to imagine that it exists solely in the mind of God, where, presumably, everything is connected. Mysterious connections and the lack of any objective reality at the quantum level lend some weight to the supernatural in this area.

So when we look at the culture war between the secularists and the believers, it is difficult to pronounce judgment in favor of either. Clearly, neither has a theory that explains what scientists have demonstrated today about the universe and the nature of reality. Nor can either hope to prove he is correct. To the extent that they believe in the correctness of their own position, both sides are simply relying on faith. In short, let’s declare a truce in the culture war and get on with something productive.

Peter J. Wallison is the Arthur F. Burns Fellow in Financial Policy Studies at the American Enterprise Institute.