This is an abridged version of a talk presented to the Greer-Heard Forum at the New Orleans Baptist Theological Seminary on Apr 14, 2012. More details and references can be found in my latest book, God and the Folly of Faith: The Incompatibility of Science and Religion.
I have not read every published report on the types of phenomena used to claim evidence that humans contain some immaterial component that makes our immortality possible. There are thousands of such reports. But I have looked at many, the ones said to be the best. None--not a single one--stands up under the same scrutiny that is applied in any science whenever an extraordinary claim is presented. Let me begin with near death experiences.
In the early 1970s, resuscitation technology had advanced to the point where more people were being brought back from the brink of death than ever before in history. A small minority of about one in five reported seeing a narrow, dark tunnel with light at the end, which the individual interpreted as a glimpse of "heaven." Some said they met with Jesus (Buddhists met Buddha) and departed loved ones. No doubt, those having these experiences were deeply moved and many said it changed their lives.
The near-death phenomenon began to get the attention of nurses and physicians who attempted systematic studies. However, the thousands of reports published over four decades are virtually all anecdotal. Let me mention one notorious example that received considerable media attention.
In the 1980s, a Seattle woman named Maria reported a near-death-experience after a heart attack. She told social worker Kimberly Clark that she had separated from her body and floated outside the hospital. There she saw a tennis shoe with a worn patch on the third floor ledge near her room. Social worker Clark checked the ledge and retrieved the shoe.
However, there is no independent corroboration of this event. And this is typical of so many of these reports. We only have Clark's report. No one could ever trace down Maria to verify her story. We have to take Clark's word for it. Later investigators found that Clark had misrepresented the difficulty of observing the shoe on the ledge. Placing their own shoe in the same position they found it was clearly visible as soon as you stepped into Maria's room.
In 2010, a book appeared called Evidence of the Afterlife: The Science of Near-Death-Experiences, authored by radiation oncologist Jeffrey Long and journalist Paul Perry. Thanks to considerable media hype, this book moved quickly to the bestseller lists. Long had gathered thousands of accounts of near-death experiences. He did this by setting up a website asking for personal narratives of such experiences. The result is the largest database of near-death experiences in the world with over 1,600 accounts.
Long announced that medical evidence fails to explain these reports and said, "There is only one plausible explanation--that people have survived death and traveled to another dimension."
In fact, there is little or no science in Long's book. It's based totally on anecdotes collected over the Internet where you can find limitless, unsupported testimonials for every kind of preposterous claim. Now, I don't insist that all anecdotes are useless. They can point the way to more serious research. But when they are the only source of evidence they cannot be used to reach extraordinary conclusions. To scientifically prove life after death is going to require carefully controlled experiments, not just a lot of unsubstantiated stories.
From my viewpoint as a research scientist, the only religious experiences of any kind worth studying are those where the subject reports a unique perception, one that they could not have known previously, which is then later corroborated. If demonstrated by solid, repeatable observations, these could provide the kind of scientific evidence for consciousness independent of the body that we might begin to take seriously and justify further study.
We can think of a simple test setup. Place a target, such as a card with a secret message, on a high shelf in the operating room, facing the ceiling so that it is unreadable not only by the patient on the table but by the hospital staff in the room. Then if a patient has a near-death experience that involves the commonly reported sensation of moving outside her body and floating above the operating table, she should be able to read that message.
This experiment has been tried several times without a single subject succeeding in reading the message under controlled conditions. I understand that more experiments of this type are now being carried out, but I haven't heard any results yet.
Researchers in the field would love nothing better than to verify the afterlife. But they are beginning to have second thoughts. One prominent, long-time investigator, Kenneth Ring has commented that after decades of research we would have by now expected more than few positive results under controlled conditions. This is the upshot of the 40 years of research. Investigators can't point to a single verifiable case in which the experiencer reported something they could not have known ahead of time.
Furthermore, none of these people returned from the dead. A flat EEG us not brain death because it only measures activity on the surface of the brain. And there is no way of determining that the experience actually happened during a flat EEG. Most likely the experience happened before or after, when the brain was highly active.
No doubt, the near-death experience itself is a real phenomenon, somewhat like a dream or hallucination, although perhaps not exactly the same. But it's still in the brain. Many features of the near-death experience, especially the tunnel vision, can be simulated with drugs electrical impulse, and acceleration. I think it's safe to say that we cannot regard near-death experiences as evidence for life-after-death. We can conclude beyond a reasonable doubt that the near-death experience is all inside the head.
Next, let's take a look at psychic studies. For over a hundred and fifty years attempts have been made to find scientific evidence for special powers of the mind that violate established scientific principles. If verified, they could provide evidence for an immaterial, immortal soul.
The scientific search for the soul began in the late nineteenth century with experiments on so-called "spiritualist mediums" conducted by prominent physicists, and devout believers, William Crookes and Oliver Lodge. Since then the history of paranormal studies has been a series of extraordinary claims of evidence for psychic phenomena, enthusiastically reported in the news media and popular books, followed by the collapse of those claims under the intense scrutiny of skeptics. More important, all have failed to be independently replicated. To the present day, paranormal studies have been plagued by insufficient care taken to rule out other, more mundane possibilities.
No properly controlled experiment in almost two centuries of psychic research has provided significant, replicated evidence for the special powers of the mind that you would expect if mind had some non-material aspect.
By the same token, considerable evidence does exist supporting the hypothesis that what we call mind and consciousness result from mechanisms in a purely material brain. If we have disembodied souls that are responsible for our thoughts, dreams, personalities, and emotions, then they should not be affected by drugs. But they are. They should not be affected by disease. But they are. They should not be affected by brain injuries. But they are.
As brain function decreases, we lose consciousness, as when under full anesthesia. Why should that be if consciousness resides in an immaterial soul? Brain scans today can locate the portions of the brain where different types of thoughts arise, including emotions and religious thoughts. When that part of the brain is destroyed by surgery or injury, those types of thoughts disappear. Let's face it; so-called spirituality is all in the head. It's purely material in nature.
You often will hear it said, "Absence of evidence is not evidence of absence." This is not true. Absence of evidence is evidence for absence when that evidence should be there. If life after death exists, then evidence should be there. It is not. Life-after-death can be ruled out scientifically beyond a reasonable doubt.