Years ago my patient Joe brought me a photograph of a remarkable scene he had painted illustrating a vision that came as he lay close to death in the ICU. At the foot of his bed Satan and Jesus battled for Joe’s soul. Jesus won and Joe was saved.

Many, but not all, agree that the brain somehow participates in spiritual experience in those rare and sublime spiritual moments when someone like Joe touches whatever they consider divine. As a neurologist I want to understand the struggle within Joe’s brain.

Neuroscience knows a great deal about how the brain works during a variety of spiritual experiences, ranging from meditation to near-death to the mystical sense of oneness. Knowledge made firm by well-established brain mechanisms that have stood the scientific test over time.

Against our intuition, we now clearly see that spiritual experience of many varieties is inextricably bound to our primal brain. When we consider the brain’s majesty, things like Beethoven’s symphonies and Einstein’s theories come to mind. However, this grandeur blinds us to the brain’s prime purpose-to keep us alive.


Many of our spiritual moments are linked to responses like the familiar "fight-or-flight." The brain structures underlying our survival impulses evolved long before other structures made the human brain capable of language and reasoning. From a neuroscience vantage, spiritual thoughts, feelings, and sensations may not be so much beyond language as before language.

True, neuroscience can blur “natural” and “unnatural” spirituality. The brain pathways used during "natural" spiritual experiences like the mystical oneness of St. Teresa of Avila are the same pathways used by spiritual drugs whose effects are indistinguishable from otherwise genuine religious conversions; drugs which can transform lives long after the substance flushes clear from the body.

Clinical neurology shows that diseases can distort these and other pathways to spiritual effect.

At the neurologist's command, a flicker of electrical current to a discrete part of the brain gives the powerful illusion that consciousness left the body to float unbounded in space.

Can “unnatural” experiences be authentic? Yes, if one agrees with William James who said of spiritual experience that "By their fruits ye shall know them, not by their roots." Dostoevsky suspected that epilepsy ignited the spiritual ecstasy he felt, and akin to James, he reasoned “What does it matter…?”

Some people fear that when science explains how the brain participates in spiritual experience, science also simultaneously explains the experience away.

This fear of science surprises me some ways.

After all, faithful Christians believe in the divine inspiration of scriptures written by Matthew the disciple of Jesus. Yet, few seem troubled that when Matthew wrote the scripture he must have used the same portions of brain that we use for everyday language, the very regions you are using now. So too spiritual experience uses everyday portions of the brain, or other portions reserved for crisis.

Of course science can’t explain everything about the brain, including spirituality.

Beyond science’s boundaries we discover faith. When transcending science’s limits, we must keep in mind that like knowledge, faith too resides within the brain since nothing is known of experience outside the brain.

Many neuroscientists, like Thomas Metzinger, hold that the brain with its own processes is incapable of fully understanding itself. The brain thereby finds itself enveloped in “a special form of darkness.”

Moreover, suppose spiritual truth were within dark energy and mass-what then? Since scientists know next to nothing about this energy and mass comprising the vast majority of the universe, what could we really expect neuroscience to tell us about the spiritual?

Compounding our uncertainty, split-brain studies tell us to be wary of our left hemisphere, the speaking half for within lies the brain’s compelling explainer and confabulator.

Today the left hemisphere gives some people reasons to distort, dismiss or disparage a spiritual essence. This includes the left hemispheres of both religious zealots and hardened atheists alike.

Do cold hard science facts suck the nectar from our spiritual potential? I think not, for it seems to me we are poised on the threshold of an era holding promise for the birth of a new kind of wisdom.

Such wisdom steels us against false hopes shielded by false science. A wisdom that dispels the “scientific proof” that out-of-body experience evidences consciousness outside the brain, or that near-death experience “proves” a return from death possible or life after death. These assertions rightfully belong in the province of personal faith, not the realm of science.

So many possibilities lie ahead that span our highest elevations to temptations of the darkest sort. And with them come challenges. The world ahead will certainly be different from anything we now know, but within that world even if we knew how each brain molecule works during these revered spiritual moments, the mysterious why of spirituality and faith lives on.

Dr. Nelson is Professor of Neurology at the University of Kentucky and author of the recently published book "The Spiritual Doorway in the Brain:  A Neurologist's Search for the God Experience" (Plume 2012).