The challenge, then, is to explain near-death experiences within a natural framework. As a longtime student of the mind-body problem, I care about NDEs because they constitute a rare variety of human consciousness and because of the remarkable fact that an event lasting well under an hour in objective time leaves a permanent transformation in its wake, a Pauline conversion on the road to Damascus—no more fear of death, a detachment from material possessions and an orientation toward the greater good. Or, as in the case of Hemingway, an obsession with risk and death.
Similar mystical experiences are commonly reported when ingesting psychoactive substances from a class of hallucinogens linked to the neurotransmitter serotonin, including psilocybin (the active ingredient in magic mushrooms), LSD, DMT (aka the Spirit Molecule), and 5-MeO-DMT (aka the God Molecule), consumed as part of religious, spiritual or recreational practices.
The Undiscovered Country
It must be remembered that near-death experiences have been with us at all times in all cultures and in all people, young and old, devout and skeptical (think, for instance, of the so-called Tibetan Book of the Dead, which describes the mind before and after death).
To those raised in religious traditions, Christian or otherwise, the most obvious explanation is that they were granted a vision of heaven or hell, of what awaits them in the hereafter. Interestingly, NDEs are no more likely to occur in devout believers than in secular or nonpracticing subjects.
Personal narratives drawn from the historical record furnish intensely vivid accounts of NDEs that can be as instructive as any dry, clinical case report, if not more so. In 1791, for instance, British admiral Sir Francis Beaufort (after whom the Beaufort wind scale is named) almost drowned, an event he recalled in this fashion:
A calm feeling of the most perfect tranquility succeeded the most tumultuous sensation…. Nor was I in any bodily pain. On the contrary, my sensations were now of rather a pleasurable cast …. Though the senses were thus deadened, not so the mind; its activity seemed to be invigorated in a ratio which defies all description; for thought rose afterthought with a rapidity of succession that is not only indescribable but probably inconceivable, by anyone who has been himself in a similar situation.
The course of these thoughts I can even now in a great measure retrace: the event that had just taken place …. Thus, traveling backward, every incident of my past life seemed to me to glance across my recollection in retrograde procession … the whole period of my existence seemed to be placed before me in a kind of panoramic view.
Local brain regions go offline one after another. The mind, whose substrate is whichever neurons remain intact, then does what it always does: it tells a story shaped by a person’s experience, memory, and cultural expectations.
Related: What Happens After Death?
Another instance was recorded in 1900, when Scottish surgeon Sir Alexander Ogston (discoverer of Staphylococcus) succumbed to a bout of typhoid fever. He described what happened this way:
I lay, as it seemed, in a constant stupor which excluded the existence of any hopes or fears. Mind and body seemed to be dual, and to some extent separate. I was conscious of the body as an inert tumbled mass near a door; it belonged to me, but it was not I. I was conscious that my mental self used regularly to leave the body …. I was then drawn rapidly back to it, joined it with disgust, and it became I, and was fed, spoken to, and cared for …. And though I knew that death was hovering about, having no thought of religion nor dread of the end, and roamed on beneath the murky skies apathetic and contented until something again disturbed the body where it lay, when I was drawn back to it afresh.