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Thoughts and Matter

Reality Check

Victor Stenger

Volume 19.4, December 2009

In his book God and the New Atheism, theologian John Haught calls naturalism “deeply self-contradictory.” He does not, however, provide any specific contradiction. The best Haught can do is assert his personal judgment that evolution will never be able to explain certain mental phenomena such as cognition. He claims that “Scientific naturalism ignores the subjective side of nature, especially our inner experience.”

I do not think it is fair to say that scientific naturalism ignores the subjective. While it is true that neuroscientists do not yet have an established material model of mind, they have considerable data on changes that occur in the brain during subjective mental activity. They have established beyond doubt that material processes are involved.

Nevertheless, Haught’s view seems to be the common refrain of theists arguing against a purely natural universe. In his book God Is No Delusion, Thomas Crean, a Dominican friar of the priory of St. Michael the Archangel in Cambridge, England, follows Haught in using the argument from ignorance fallacy, saying he cannot understand how thoughts could emerge from matter, and therefore they must have come from God. He asks, “How could a ‘material kind of thing’ cause an ‘immaterial kind of thing’ to exist?” Well, a computer is a material kind of thing that can solve mathematical and logical problems. It can write poetry that English professors are unable to distinguish from that written by humans. It can produce beautiful art and music. The aesthetic experiences of these products are immaterial “kinds of things,” but they result from physical brain activity.

Unaware of these facts, Crean continues in the same vein, “Materialism, then, is absurd. A thought cannot be a material thing, nor can it be caused by a material thing. The only possible conclusion is that thought as such is something independent of matter, that is, something spiritual.”

In their short book Naturalism, philosophers Stewart Goetz and Charles Taliaferro attempt to show that naturalism is intellectually incoherent. The authors are theists who teach at Notre Dame University and St. Olaf College, respectively. They claim that a duality of the physical and the mental is necessary to explain mental causation, that is, how mental events cause physical events.

This strikes me as rather backward. If, as naturalism asserts, mental events arise from physical events in the brain, then there surely is no problem since we then have physical events causing physical events, just as when a cue ball hits an eight ball and causes it to go into a pocket. On the other hand, if mental events have their own nonphysical nature, then we have the problem of explaining how something nonphysical can cause physical events. Goetz and Taliaferro do not provide us with even a speculative model for how that can happen.

When theists such as Goetz and Taliaferro refer to gaps in the scientific record, the best they can do is say, “See, God must have done it.” This provides no more information and is less economical than the simple statement: “Nature did it.” But materialists can usually do much better than this simple assertion and give some idea of how nature did it. In a physical explanation we often have a theory, such as relativity or evolution, that provides detailed mechanisms for the events being observed. Even when we do not have an existing established theory, such as for the origin of life or mental processes, we have plausible proposals under consideration that agree with all existing knowledge and that require no supernatural elements. Theists can make only the simple assertion, “God did it.” Scientists can say, “We don’t know. But we’ll try to find out.”

Of course, mind-body dualism is a widespread “commonsense” belief among laypeople. Goetz and Taliaferro seem to think common sense is sufficient to adopt the dualist view.

Goetz and Taliaferro also claim to show the philosophical coherence of divine agency. So what if it is philosophically coherent? That says nothing about its reality. A fantasy computer game in which heroes come back to life after being killed is philosophically coherent; it wouldn’t run on a computer if it wasn’t logical. But the world is still not that way.

Philosopher Paul Churchland points out that throughout history people have expressed doubt that science will ever be able to explain some phenomena. The first-century astronomer Ptolemy (c. 85–165), the greatest astronomer of his age, said science would never be able to capture the true nature of heavenly causes because they were inaccessible. He didn’t have Newton’s inspiration that the laws of physics are universal, meaning they apply both on Earth and in the heavens. The nineteenth-century philosopher Comte (d. 1857) similarly argued that we could never know the physical constitution of stars. He didn’t know about atomic spectra. As late as the 1950s, most people were still expressing doubt that life could be explained purely materialistically and believed instead that some life force was needed. With the 1953 discovery of the structure of DNA and the great success of the theory of evolution by natural selection, science saw no need for, and indeed no evidence for, a special force of life.

When the mental dualist asks, “How can thoughtless matter give rise to thought?” he is expressing the same argument from ignorance fallacy used by those who say, “How can dead matter give rise to life?”

Many questions remain unanswered by those who claim that some immaterial spirit or soul is ultimately controlling the actions of the brain. How does this immaterial thing that carries no energy or momentum provide energy and momentum to particles in the brain? This implies violations of conservation of energy and momentum, which the theist believes are God’s laws. Why is it okay to break these laws of God and not his other laws, such as his ban on homosexual marriage and using condoms?

Further Reading


This is adapted from Stenger’s latest book, The New Atheism: Taking a Stand for Science and Reason (Prometheus Books 2009).

Victor Stenger

Victor J. Stenger is emeritus professor of physics and astronomy at the University of Hawaii and Visiting Fellow in Philosophy at the University of Colorado. His latest book is The Fallacy of Fine-Tuning: How the Universe is Not Designed for Humanity. His previous books include Not By Design, Physics and Psychics, The Unconscious Quantum, and Timeless Reality: Symmetry, Simplicity, and Multiple Universes.