The Pope, Evolution, and the Soul

Mario Bunge

John Paul II has recently admitted that biological evolution is for real. This is no news: Pius XII had admitted it in 1953. But he had warned that evolution, far from happening spontaneously (naturally), is guided from above. (How did he find out?)

If evolution had been steered at a distance by God, then natural selection—one of the two main evolutionary mechanisms—would not be natural. It would be supernatural, hence mysterious and, there-fore, a matter for theologians, not biologists. Clearly, the evolutionary biology authorized by the Vatican is not the one biologists work on.

The latest contribution of the present pope to the age-old religion-science debate consists in reiterating the dogma that the human soul is immaterial and eternal, so that it is free from the shackles of matter and the accidents of evolution. This mil-lenary dogma poses a number of problems that theologians have not even tackled.

  1. How is it possible for the human brain to have evolved without its specific functions having evolved as well? Do not the functions of an evolving thing change along with the thing itself? And has not biopsychology found that mental functions such as perception, attention, emotion, imagination, conjecturing, and decisionmaking are brain functions? If so, is it not obvious that mental functions are evolved with their organ, namely the brain? And is it not for this reason that evolutionary psychology is being cultivated?
  2. If the mental processes are not neurophysiological processes, why is the human brain the most complex and vulnerable of all organs? If it did not discharge the most exquisite imaginable functions, why could we not manage with a far smaller and nearly empty skull, useful only for wearing a hat or butting a soccer ball?
  3. If only the human mind is divine, how do the other primates, as well as many other higher vertebrates, manage to perceive, learn, and communicate, some-times even with us?
  4. If the human mind is divine, whom did the Holy Ghost endow with it, and at what stage in evolution? Was it the hominids three million years ago, or only Homo sapiens, that presumably emerged just 100,000 years ago? And before the miracle happened, were our remote ances-tors soulless? If not, were they more soul-less than the Crusaders, the Inquisitors, and the Christians who fought so fer-vently for the various fascist causes since 1925, and who continue to kill each other in Northern Ireland?
  5. If the soul is alien to evolution, how can we explain that some of our mental activities are vastly superior to those of our remote ancestors? Could it not be because mental evolution has accompa-nied biological evolution?

These are not the only problems with the mind-body dualism preached by theologians and philosophers who willfully ignore modern psychology. The most serious problem with that dogma is that it hinders the scientific investigation of mental processes, as well as of the medical treatment of mental disorders.

In fact, the pope has tacitly warned neurobiologists and psychologists that they should confine their study of the brain to its non-mental functions, as well as to abstain from studying apes, monkeys, and other more or less remote relatives of ours in order to find out how the mind works. But these investigations are, precisely, those that have resulted in some of the most sensational findings over the past half a century.

For instance, thanks to the various imaging techniques, it is now possible to unveil the brain mechanisms of speech, reading, and writing—surely some of the most outstanding mental activities. (Could divine grace be a substitute for positron emission tomography scanning and magnetic resonance imaging?)

Another example: the scarcity of serotonin, a key neurotransmitter, causes depression. This disabling disorder can now be treated with the famous drug Prozac, which controls the concentration of serotonin by the brain, and thus restores its normal level. (Could prayer be an equally effective as well as a far less expensive technique?)

Moreover, it has been known for decades that iodine deficiency can cause not only goiter but also idiocy; that protein deficiency slows down learning; that a lesion in the parietal lobe may cause aphasia of some kind or other; that some forms of hyperactivity can be treated with drugs, and others by the surgical removal of a slice of the thyroid gland. (Can exorcism beat these feats?)

It has also been ascertained that the neocortex is the organ of intelligence, and the limbic system the organ of emotion; that the perceptions of color, shape, and movement are functions of so many distinct “areas” of the cortex; that knowing “what” is localized at a different place than knowing “where”; and so on and so forth. The curious reader can consult any modern textbook in physiological psychol-ogy—or psychobiology, or biopsychology, or neuropsychology. (Has theology helped in any way to make these discoveries?)

These and many other findings concerning the mind-body problem have lengthened enormously a list that the medical profession has been compiling for nearly three millennia. In fact, the ancient Egyptian and Greek physicians knew that certain brain lesions affect the mental functions. They also knew that certain drugs and beverages affect mood, others perception, and still others attention, memory, intelligence, or what have you. So much so, that today’s mental health professional is tempted to prescribe a specific pill for nearly every mental disorder.

If the soul (or its secular version, the mind) were immaterial, it could not be affected, much less destroyed, with drinks or pills, surgery or beating. And if mental disorders were mere dysfunctions of a ghostly entity, they could not be corrected with drugs or the lancet. We could perform spiritual exercises even while running or swimming vigorously. And lack of oxygen, as at great heights, would not diminish our mental faculties to the point of causing hallucinations, such as visions of flying saucers or apparitions of the Virgin Mary.

It is by treating the human brain as the organ of the human mind that psychological mechanisms, normal and pathological, are being unveiled. That is, the materialist approach taken by bio-psychologists—as well as by physicists, chemists, and biologists—is the one that has been driving the quick advances of psychology and psychiatry over the past fifty years. (Incidentally, materialism in the broad sense does not deny the mental, in particular consciousness; it just holds that everything mental is neurophysiological, though not conversely.)

By contrast, the spiritualist (or idealist) approach, typical of religion, psychoanalysis, and idealist philosophy, obstructs the advancement of knowledge, and, therefore, that of the treatment of mental disorders. It is like trying to study movement without bodies, wind without air, digestion without the gut, heartbeat without the heart, and smiles without facial muscles. It is magic, not science.

Given the enormous price in ignorance and human suffering exacted by dogmatism, the pope’s statement on evolution is a tragicomic rather than an amusing episode in the millenary warfare between science and religion. For those who suffer from depression, schizophrenia, epilepsy, aphasia, dyslexia, or any other mental disorder, it will not come as a consolation to learn that they should expect no help from research because God (or rather His Vicar) has uncoupled the soul from the brain.

Novelties do not come from mindless repetition of moth-eaten dogmas, but from free (though disciplined) search for truth. And all religions have opposed and will continue to oppose this search in the name of eternal revealed truths.

It is depressing that one should have to repeat such truisms, which were commonplace in the age of the Enlightenment, on the eve of the third millennium. Is it because we are not progressing as much as they say? Or rather is it precisely because we are running so fast that the guardians of dogma attempt to erect barriers to the advancement of the most glamorous science, the one that is uncovering the brain mechanisms of the mind and thus laying finally to rest the dogma of the immaterial and immortal soul? As Don Quixote once said: “They bark, Sancho: a signal that we are advancing.”

Mario Bunge

Mario Bunge, a physicist by training, is the Frothingham Professor of Logic and Metaphysics at McGill University, Montreal. He is the author of more than four hundred articles and thirty-five books on physics, metaphysics, semantics, epistemology, philosophy of science, ethics, etc. His latest book is Finding Philosophy in Social Science (Yale University Press, 1996), and his book with Martin Mahner, Fundamentals of Biophilosophy, is about to be published by Springer. He is a Humanist Laureate of the International Academy of Humanism.


John Paul II has recently admitted that biological evolution is for real. This is no news: Pius XII had admitted it in 1953. But he had warned that evolution, far from happening spontaneously (naturally), is guided from above. (How did he find out?) If evolution had been steered at a distance by God, then natural …

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