Can the Brain Decide Whether God Exists?

John Shook

Science studies nature, and our brains are part of nature. Brains naturally produce beliefs—lots of them. Some of those beliefs are about nature, and others are about God. God is unnatural, yet beliefs about God are natural. It’s a curious situation: why do natural brains produce beliefs about the supernatural?

Brain scientists are working on the explanations for just such beliefs. Inspired by neuroscience, cognitive science, and psychology, religious believers are then jumping to further conclusions about God by constructing “neuro-theology.” Because the human brain naturally produces religion, it is quite reasonable to believe in God, they claim. Old-fashioned theology involves complicated arguments defending elaborate creeds. But a new “scientific” theology, based on brain science, could be a great shortcut to God. If human brains normally make people have religious beliefs, then it must be that people are supposed to be religious!

This neuro-theological argument for God is a variation on the “universal consent” argument for God. Because most people who have ever lived have been religious, belief in God must be reasonable, or so goes that argument. Will brain scientists confirm this reasonableness as more and more about religious belief gets explained by the natural brain processes that go on in so many brains? Not believing in God is an abnormal deviation from proper brain functioning, it may seem. Naturally, nonbelievers don’t feel that they suffer from abnormal brains—they regard religious brains as abnormal. Some peoples’ religious experiences and convictions are generated by diseased or disrupted brains, no doubt. All the same, brain scientists are finding explanations for why much religious experience and belief can arise from normal brain functioning. Religions arose during bygone eras of deep human ignorance, but our ancestors’ brains had basic cognitive abilities identical to our own.

Nonbelievers can’t keep supposing that all religion is the result of brain malfunctioning. However, some nonbelievers want to construct a “neuro-atheology” that disproves God using neuroscience. Atheology, as I describe in my new book, The God Debates, designs arguments against the existence of God. By recruiting the help of brain scientists, atheology might be strengthened. The neuro-atheology strategy claims that natural explanations for religious belief can rule out anything unnatural. Religious belief is entirely natural in origin, and, therefore, adding any god is the unnatural and unnecessary mistake. Since belief in religion is all-natural, this strategy concludes, there can’t be any god for those beliefs to be about.

Both neuro-theology and neuro-atheology are inspired by the same thought: if it’s natural, then it is better. Is nature always better? This popular notion sells plenty of “natural” products in the marketplace. Although “Natural is better” expresses some common sense, there are too many exceptions to the rule. We now live in a mostly artificial and synthetic world, surrounded by invention, artifact, and machine. We have to be skeptical toward the notion that “Artificial is better.” Is polyester better than cotton? Is white bread better than brown? Is bottled water better than tap? Judging each choice on its own merits cannot be avoided, because neither formula, “Natural is better” nor its opposite, can be trusted. Nature is not inherently good or bad.

There is a deep flaw at the heart of both neuro-theology and neuro-atheology. When it comes to the God question, merely having a natural brain is not enough. All the same, our natural brains can decide whether God exists if we use them carefully. Let’s take a skeptical look at these God debates.

Naturalizing Religion

Nature transcends our human judgment of good and bad—it can’t tell us what ought to be. A moral “ought” cannot be deduced from any natural “is.” Out in nature, the “Is-Ought” problem really is no problem at all. It is only a problem if we try to impose our values on nature. Resisting the temptation to ground preferential “oughts” on nature’s ways is the wiser course. Besides, nature does so many things in almost infinite variety. Just because nature is doing something, that fact cannot make it right or wrong. We must take responsibility for adding our own judgment, drawing our own conclusions about what should happen. When we try to evaluate what nature is doing, we commit no fallacy, as long as we are explicit about the values we are promoting.

Neuro-theology commits the Is-Ought fallacy, and neuro-atheology risks committing that same fallacy as well. It is understandable that some atheists would try to use naturalism to pass judgment on religious belief. After all, if neuroscience can account for religious belief, then nothing supernatural is needed and religious stories about gods causing belief are irrelevant. Because people naturally have religious beliefs, people should stop having religious beliefs.

Wait a minute—that is a confusing claim: “Because people naturally have religious beliefs, people should stop having religious beliefs.” Should atheists be making this claim? We are seeing this kind of challenge thrown down in popular atheist literature. And it is not just heard from atheists impressed by brain science. There are useful explanations for religious belief also arriving from sociology, cultural anthropology, and various interdisciplinary fields. This larger enterprise of formulating naturalistic accounts of religion is proving to be highly useful for understanding why humanity has been so religious for so long. Naturalizing religion is a powerful contribution from science and commits no Is-Ought fallacy. We are here concerned with atheological arguments against the existence of God, which could be grounded on naturalizing religion. Once religion is naturalized, should God disappear?

This strategy, which can be labeled as the “naturalize religion” strategy for atheism, has many new admirers as the cognitive and behavioral sciences produce reasonable explanations of religion. The science seems fairly sound. However, the “naturalize religion” strategy risks committing an Is-Ought fallacy. It is unnecessary to take such a risk when advancing atheism. When atheists try to proceed directly from science’s knowledge of nature to a value judgment against religion, they go well beyond the long-familiar skeptical strategy against religion. That skeptical strategy argues that because science supplies adequate rational explanations, religious appeals to divine powers are simply unnecessary errors. No one should have religious beliefs, the skeptical argument goes, because religions demand beliefs that either directly violate scientific knowledge or simply fail to do any explanatory work at all. The “scientific skepticism” approach is a time-tested, logical strategy for advancing atheism. It is a long-term, slow strategy, admittedly. Showing impatience, some atheists hope that scientific explanations for religious belief can dramatically accelerate their war against religion. But does a “naturalize religion” strategy really do the work that atheists hope?

Is Religion Unreasonable Because It Is Natural?

Let us examine a specific example of this naturalizing religion strategy for atheism. In the following argument, a psychological explanation of religious belief supplies the factual premises. Its conclusion makes a normative judgment that no one should be religious.

    1. Religious belief in the supernatural frequently satisfies some important psychological needs of humans.

Humans naturally tend to prioritize things that contribute to satisfying their important psychological needs.

  • Hence, humans naturally tend to prioritize religious beliefs and often adjust them for consistency with other vital needs.
  • Nothing supernatural is needed to explain the psychological basis of religious belief.
  • Therefore, it is unreasonable for anyone to sustain religious belief in the supernatural.


Notice how this naturalistic argument first supports premise 3, which can explain why religion has been so prevalent across humanity. Premise 4 then reminds us that only naturalism is needed for explaining religion in this way. Finally, the conclusion (5) points out how it is unreasonable to believe in something, like God, that is entirely irrelevant to having religious beliefs.

If this psychological argument against God initially strikes you as jarring or confusing, then you have read it correctly. The argument needs some clarification. As it stands, it just doesn’t seem to get as far as an atheist may hope. My suggestion is that this argument is making a dangerous logical leap from an “is” to an “ought.” That gap could be bridged by some extra value judgment. To bridge the gap between 4 and 5, an extra evaluative judgment is required, along the lines of “No one should accept a supernatural explanation when there is a sufficient naturalistic one.”

Neuro-theology is ready to raise a counterargument for God, and it also requires an extra evaluative judgment to work. Here is an argument defending religious belief, which starts with naturalistic premise 3 from the first argument, but it then draws the opposite conclusion.

  1. Humans naturally tend to prioritize religious beliefs and often adjust them for consistency with other vital needs.
  2. It is naturally reasonable to prioritize religious beliefs and to modify religion where necessary.
  3. Hence, people can be quite reasonable for having suitable religious beliefs in the supernatural.
  4. Therefore, it is unreasonable for anyone to demand the surrender of all religious belief in the supernatural.

This theological reply to atheism also leaves a logical gap: there is a hidden value judgment at work here that whatever is quite natural is also quite reasonable.

We are left with a theological-atheological standoff. Both camps can point to scientific support for their positions, and both camps must be relying on tacit value judgments. Our initial question remains unanswered: Does better understanding of the brain diminish the reasonableness of religion or increase it? As we have seen, the science itself is inadequate to determine a winner. It doesn’t matter which science—neuroscience, psychology, sociology, anthropology, meme theory, etc.—this stalemate extends across all fields’ factual theories about how beliefs form. More knowledge about how our brains do what they do cannot help this situation at all. The brain, as a natural thing, cannot determine whether God exists.

We Still Have to Use Our Brains

Of course, human brains can judge whether God exists—but only when they are used correctly. The brain, as an intelligent thing, can decide whether God exists. Beliefs arise in all sorts of ways; what matters more is the way that beliefs ought to form and get accepted. We must watch out for a variation on the Is-Ought fallacy lurking when we consider brain processes themselves. Nonrational thinking goes on in lots of “normal” brains, but “normal” thinking doesn’t make it right. Lots of brains can be quite wrong.

Simple religious ideas probably arose quite naturally to our more thoughtful ancestors, but the complex belief-systems of religions no longer leave belief formation to chance. Religions try to control belief formation with their characteristic appeals to imagination, emotion, and mysticism. Those appeals work on normal brains, explaining the prevalence of religion, but prevalence of a belief doesn’t make it right. For their part, nonbelievers try to control their beliefs as well, advocating methods of sound reasoning from reliable evidence. But it is all about deliberate control of belief, for everyone. There is no innocently good way of “natural belief” anymore, not for us at this advanced stage of human civilization. Neither religion nor atheism is “more natural” for us.

Most of us live in sophisticated cultures now, and our cultures set standards about correct belief formation and exercise some control over beliefs. We must take responsibility for evaluating and controlling our methods of knowledge. That was the point of the “scientific skepticism” approach to atheism. When judging whether people ought to have religious beliefs, we can add our additional value judgment of “people ought to believe things only on sufficient evidence.” If more people lived in cultures that prioritized reason and science, then the persuasive opportunities for religions would be much diminished. Advocates for atheism think that we ought to live in cognitively improved cultures. This is already evident in the “scientific skepticism” strategy, wherein the atheist advocates the value judgment that people ought to believe things only on sufficient evidence.

To further see why atheists must advocate a cognitively improved culture, consider how the atheist should reply to neuro-theology. To make an effective reply to this argument, the atheist needs to reject premise 7. To do this, the atheist must instead openly advocate for a more reasonable culture, one that does not simply obey any common psychological need. To do this, there are two main options for the atheist:

  1. The atheist can claim that people should not want to satisfy the psychological needs that can lead to religious belief. We need to artificially design and promote a nonreligious culture that produces adults who don’t have such psychological needs.


  1. The atheist can claim that people should satisfy the psychological needs that can lead to religion, but only by using nonreligious substitutes. We need to artificially design and promote a secular culture that satisfies those psychological needs even better than religion.

Either way, the atheist is going well beyond the brain sciences themselves, which cannot inform us about what kind of culture we ought to have. It is one thing to naturalistically account for the existence of religious beliefs. It is a separate matter to judge that people should be more rational, that people should stop holding religious beliefs, and that no God exists.

The replacement of religion with a secular alternative involves advocating evaluative judgments about belief formation and cultures. That goes well beyond any science, and advocates of atheism who do this are doing philosophy, not more science. Advocates of religion who claim that because brains produce religions then religions are naturally reasonable are similarly transcending anything that science could justify. By trying to leap directly from what is natural to what is best, both camps could only commit the Is-Ought fallacy and remain stuck in a stalemate.

What can be concluded from our examination of this debate about the brain sciences? The “scientific skepticism” approach remains a powerful atheological strategy against religious belief. By asking people to not just use their brains but to use them rationally, skepticism explains why people should not believe in God. When atheists next ask people to replace their religions with all-natural alternatives, their cultural evaluations should also be openly explained and defended. Atheists must take a principled cultural stand somewhere. Nature has produced humans capable of many kinds of cultures, and science describes how humans can adhere to many kinds of belief systems. But which beliefs and cultures are best? No field of science is responsible for empirically confirming a normative judgment like “scientific method is the best.” Neither nature nor science is enough to replace religion. It’s time to fight for the kind of culture that we think is best.

John Shook

John Shook is an associate editor of FREE INQUIRY and director of education and senior research fellow at the Center for Inquiry. He has authored and edited more than a dozen books, is coeditor of three philosophy journals, and travels for lectures and debates across the United States and around the world.

Science studies nature, and our brains are part of nature. Brains naturally produce beliefs—lots of them. Some of those beliefs are about nature, and others are about God. God is unnatural, yet beliefs about God are natural. It’s a curious situation: why do natural brains produce beliefs about the supernatural? Brain scientists are working on …

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