10/23/2012 08:46 am ET Updated Dec 23, 2012

The Argument from Ignorance

To surrender to ignorance and call it God has always been premature, and it remains premature today.
-- Isaac Asimov

In my last HuffPuff, "Not Dead Experiences (NDEs)" I remarked that neurosurgeon Dr. Eben Alexander had used the "argument from ignorance" in claiming that his personal near-death experience provided proof of the reality of heaven. His book Proof of Heaven: A Neurosurgeon's Journey Into the Afterlife (Simon & Schuster) has just been released.

Several readers asked how I could accuse Alexander of ignorance given his credentials as a neurosurgeon. I did not accuse him of ignorance. I said he was using the argument from ignorance. I am sure he is a very knowledgeable and experienced neurosurgeon. However, performing brain surgery requires very different intellectual and physical skills from those required for understanding how the brain works. Some people are astronauts; others are astrophysicists. Alexander is not a qualified neuroscientist and may not be aware of the proposed natural mechanisms for near-death-experiences, consistent with existing knowledge, that have been described in the scientific literature.

Alexander is quoted as saying, "According to current medical understanding of the brain and mind, there is absolutely no way that I could have experienced even a dim and limited consciousness during my time in the coma, much less the hyper-vivid and completely coherent odyssey I underwent." That is, just because his medical expertise doesn't include an explanation of his experience, no scientific explanation is possible. This is the argument from ignorance: just because Alexander doesn't know the answer, no answer can ever be found.

As I explained in my previous article, the argument from ignorance is a logical fallacy, also known as the God-of-the-gaps argument, whereby someone says, "I am unaware of a natural explanation for [some phenomenon]; therefore we have evidence for the supernatural." The argument fails because it does not prove that a natural explanation will never be possible.

Until evidence is found that cannot be plausibly explained naturally, the more parsimonious conclusion that is forced upon us by reason and Ockham's razor is that the phenomenon is purely natural. Let me put it this way: What is more likely to be correct? (1) After thousands of years of searching, we finally have here, in the personal anecdote of a medical doctor, not trained in objective scientific research, scientific proof of life after death. Or, (2) The NDE experience was all in his head.

As I pointed out, one can think of examples of religious experiences that would be difficult or even impossible to explain naturally. All that has to happen is that the subject return with knowledge that could not have been in her head all along.

In recent days, we have seen the appearance of another variation on the claim that there must be more to the world than the purely materialist picture provided by physics, biology, and neuroscience.

Philosopher Thomas Nagel has just published a book titled Mind and the Cosmos: Why the Materialist Neo-Darwinian Conception of Nature is Almost Certainly Wrong (Oxford). According to the publisher's synopsis, "The modern materialist approach to life has conspicuously failed to explain such central mind-related features of our world as consciousness, intentionality, meaning, and value. This failure to account for something so integral to nature as mind, argues philosopher Thomas Nagel, is a major problem, threatening to unravel the entire naturalistic world picture, extending to biology, evolutionary theory, and cosmology."

Nagel is quoted as writing, "The world is an astonishing place, and the idea that we have in our possession the basic tools needed to understand it is no more credible now than it was in Aristotle's day." Now there's an argument from ignorance if there ever was one. We are just as ignorant of scientific methodology today was we were in Aristotle's day!

Here I must admit that I have not yet read the two books, they having been just released; I am going by quotations, reviewer comments and publishers' summaries. Nevertheless, it appears that, while Alexander is a practicing Christian, Nagel is a professed atheist and his goals seem less clear. Nagel seems to claim problems with materialism and Darwinism, in particular the reduction of everything to physics.

Neither author provides objective data to support his conclusion, each of which is presented with dogmatic certainty. Alexander has only his subjective experience to go by, which he then interprets with his limited knowledge of the brain. Nagel also relies on the subjective, arguing that science "flies in the face of common sense," that it is so inconsistent with "evident facts about ourselves," that it "require[s] us to deny the obvious."

The only "evident facts" that are worth considering are objective facts. And any number of objective facts exist that strongly support the view that the thinking process is a purely material phenomenon. Otherwise, why would thoughts be affected by drugs, disease, and brain injury?

The world, as Nagel observes, is indeed an astonishing place. But this does not mean that we must accept, on the basis of such non-scientific ''evidence'' as Alexander and Nagel present, that some ingredient other than matter must be introduced to understand the observations of the world made with our senses and scientific instruments.

This is the only rational position one can take given our current level of knowledge. It is not a dogmatic position, however. When and if real evidence for an immaterial world becomes available--not subjective anecdotes and empty philosophical arguments--then scientists are more than ready to follow whatever direction that evidence leads.