The best empirical evidence for life after death comes from people who have had "near death experiences" (NDEs). These are people who have gone to the edge and come back with a report. Certainly they haven't crossed over; in that sense, death remains, as Shakespeare put it, the undiscovered country. But so-called NDEs give us the best chance to make at least an initial map of that unknown territory.
NDEs were first publicized in 1975 by physician Raymond Moody in Life After Life. Moody described 150 cases of people very near death, or pronounced clinically dead, who reported experiences of moving through dark tunnels, seeing themselves from outside their bodies, encountering the spirits of dead relatives and friends, seeing celestial beings, being dazzled by a bright light, reviewing their whole life in an instant, and then reaching an impassable barrier before being returned to their earthly bodies.
Recognizing that his reports would sound fantastic to many, Moody cited numerous examples from history to show that NDEs were not uncommon. Plato reports one in the last pages of his Republic. The eighth-century monk Bede gives a similar account in his history of the English people. The Tibetan Book of the Dead instructs dying people to prepare to give an account of their lives as they go through the darkness into the radiant light of pure reality. Even the atheist philosopher A.J. Ayer wrote of a near death experience in which he found himself in a realm where "the laws of nature had ceased to function" and where he was "confronted by a red light, exceedingly bright."
Gallup surveys and studies around the world have subsequently shown that such experiences occur frequently. The stunning implication is that consciousness can survive the termination of bodily functions -- that death may not be "final exit."
Recognizing the implications of NDEs, atheists have labored hard to refute them. One explanation, favored by Carl Sagan in Broca's Brain, is that at the end of life we, in a sense, return to the womb and once again experience the original birth process. An ingenious idea: it would account for several features of NDEs, such as the tunnel, the sensation of floating, the movement from darkness to light.
But Sagan's hypothesis has been largely discredited by the work of philosopher Carl Becker, who draws on research in the field of infant perception to show that newborns cannot see anything as they emerge from the womb. Even if they could, newborns don't have developed mental faculties and cannot be expected to have recollections of the birth process. In any case, the birth canal is not like a tunnel through which a child gracefully floats; it is a tight, compressed passage from which a newborn emerges, typically head first and sometimes chafed or bruised.
A second explanation is that NDEs reflect distorted brain states. Psychologist Ron Siegel suggests they are dreamlike experiences of a kind that people have when they take hallucinogenic or mind-altering drugs. Those who take recreational drugs do experience a range of perceptions from wild colors to soaring sensations to drowsiness to decreased vision. During this time however, most of them know they are on drugs. Also they don't have anything like the coherence of the near death experience. Finally people who have NDEs aren't typically on recreational drugs -- many aren't even on anesthetics, narcotics or painkillers.
Neuroscientist Michael Persinger claims he can simulate the NDE by placing a helmet on subjects and electrically stimulating parts of their brains. Persinger's helmet is a hit-or-miss device; atheist Richard Dawkins tried it, and it had no effect on him. Others have a spiritual feeling but not the particular features of the NDE. The bigger problem is that this is an artificially induced state. If I tell you that I am being blinded by the sun, you cannot prove this is a mental illusion by showing me that you can also blind me with a flashlight. NDEs not only occur with no external inducement; they also happen to people whose hearts and in some cases brains have stopped functioning altogether.
Perhaps the most plausible explanation for NDEs is given by psychologist Susan Blackmore, who seeks to account for them through her "dying brain hypothesis." Blackmore suggests that when the brain breaks down, its mechanisms of pattern recognition continue to generate images. In other words, the brain attempts to reconstruct a memory model of reality that seems perfectly real, even though it does not reflect anything outside the brain itself.
The strength of Blackmore's theory is that it explains important features of the NDE. The tunnel is the result of constriction in the visual pathways. The lights are a kind of special effect generated by a brain cortex that is deprived of oxygen. A breakdown in body image and the brain's model of reality can account for the feeling of being outside one's body. The life review is a consequence of the brain's memory systems trying to organize themselves as they fail and falter. The same memory systems conjure up images of deceased relatives and friends. Finally, the impression of timelessness is fostered by a self that is disintegrating and relinquishing all experiential notions of time and place.
The only problem is that Blackmore offers no empirical evidence that dying brains actually generate all these experiences. It seems obvious that they don't, because if they did, then virtually everyone who is dying would have an NDE! Moreover, as those who have watched a loved one die can easily testify, dying brains tend to produce faded recollections, incoherence and disorientation. These symptoms are radically different from the perceptual clarity and bliss of the typical NDE.
If NDEs are the result of a dying brain, then a breakdown of mental faculties has already taken place, but in fact most people who report NDEs are now living normal lives. So how have their brains reversed the dissolution and gotten all their normal perceptual faculties back? This reversal defies medical explanation and Blackmore provides none.
The bottom line is that near death experiences have so far withstood all efforts at refutation. The critics continue to speculate -- it may be this and it may be that -- but on balance NDEs suggest that consciousness can and sometimes does survive the cessation of heart and even brain functions. True, NDEs don't tell us much about what the afterlife is really like. Nor do they indicate how long this postmortem awareness continues: "survival" is not the same thing as "immortality." Near death experiences do seem to show, however, that death is not always the end; there may be something more.
Dinesh D'Souza's new book Life After Death: The Evidence is published by Regnery.
HuffPost Lifestyle is a daily newsletter that will make you happier and healthier — one email at a time. Learn more