Consciousness Is Not Computable
A key principle of materialism and physicalism is that all processes must be reducible to matter and energy.
In the march from molecules to man, materialists must not encounter any insurmountable hurdles: any observable facts that cannot be reduced to processes beyond matter and energy. That’s because matter and energy are all that exist. Materialist reality cannot countenance anything irreducible to those entities. Already they have a candidate for the insurmountable hurdle, because the proposition of materialism itself is immaterial. As Robert Jastrow said,
[Film courtesy of Illustra Media, at TheJohn1010Project.com]
Ignoring that show-stopper, the materialist faces several other candidates for insurmountable hurdles: (1) the origin of the universe, (2) the origin of heavy elements, (3) the origin of the Earth, (4) the origin of life, (5) the origin of multicellular life, (6) the origin of sex, and (7) the origin of consciousness. Consider that last one. If consciousness were reducible to material processes, it should be computable. In other words, a sufficiently programmed computer should be able to re-create consciousness. (Ignore the conundrum for now that programming implies a programmer, which implies intelligent design.)
An article by Subhash Kak from Ohio State, published at Live Science, explains flatly “Why Computers Will Never Be Truly Conscious.” One should never say never, but Kak is convinced that artificial consciousness is forever beyond the reach of robots and computers. It’s not a limitation of technology. His conclusion derives from the nature of human consciousness, that inner experience of self that is our closest experience of reality. We humans are aware of our thinking. Computers are not. Kak relates a thought experiment by the late Alan Turing that illustrates the problem: Try to prove that a program will stop on its own. Another computer, monitoring the program, would have to rely on a stop-checking algorithm to decide if it will stop or not. But a deceptive programmer codes the program to do the opposite of what its stop-checking routine says it will do. Kak describes what will happen:
Running the stop-checking process on this new program would necessarily make the stop-checker wrong: If it determined that the program would stop, the program’s instructions would tell it not to stop. On the other hand, if the stop-checker determined that the program would not stop, the program’s instructions would halt everything immediately. That makes no sense — and the nonsense gave Turing his conclusion, that there can be no way to analyze a program and be entirely absolutely certain that it can stop. So it’s impossible to be certain that any computer can emulate a system that can definitely stop its train of thought and change to another line of thinking — yet certainty about that capability is an inherent part of being conscious.
Human consciousness is also distributed throughout the brain (or at least activates disparate parts of the brain), Kak adds, as he recounts other show-stoppers to the computation of consciousness thought up by scientists and philosophers. So if consciousness is not computable, that makes it a strong candidate for a hurdle too high for reductionist materialism.
Not Just One Man’s Difficulty
Like Thomas Nagel, author of God and Cosmos, philosopher of mind David Chalmers would prefer to stay satisfied with a material universe. Both of them, however, only have highly speculative and untestable ways to maintain their preference. In a well-stated interview on YouTube re-posted by Evolution News, Chalmers delves into the “hard problem of consciousness.” None of us can doubt our own consciousness, he says; it is the most direct experience we have. We can doubt other people’s consciousness, but not our own. He illustrates it with zombies—not the living dead, but theoretical zombies that appear and behave just like us but are not conscious.
“When God created the world,” Chambers speculates (ironically for an atheist), He could have created a material world without consciousness. “That would make sense,” he says; it would be logically conceivable. But consciousness is something God would have had to add as a separate thing. Even taking out God, the problem remains that consciousness is separate from materialism, and superfluous to a material reality.
Chalmers then dispenses with evolutionary theory as a source of consciousness. Theories about this are generally vague and doubtful, he says. The main problem, though, is that evolution has no need to invent consciousness. The world could work perfectly well without it. An evolutionist’s world would work just fine with complex reflexes and behaviors programmed by genes. Evolution also cannot explain qualia, the direct experiences we have of the world. A color-blind person can know about colors, but cannot have the experience of red unless cured of colorblindness. Chalmers concludes that humans will never be able to solve the hard problem: Why is our behavior and sensation accompanied by conscious experience? Scientists will never find that in neurons, he argues.
How many show-stoppers does it take to stop a show? All the other insurmountable hurdles listed above for molecules-to-man evolution in a materialistic universe remain. But here we see three prominent experts in physics and philosophy of mind, who are non-Christians, stating explicitly that materialism is missing something critical. Two of them say that consciousness is permanently beyond the reach of materialism. So readers do not have to take our word for it that the materialist show is stopped. We would just heighten the hurdle infinitely further by saying that the very use of language by these thinkers requires supernaturalism. Every proposition depends on logic (which must refer to timeless, universal and necessary truths), and morality (which assumes that the speaker desires to share his logic honestly). The materialist show, therefore, is stopped; go to another show. There’s a good one across town about a Creator. It’s called the greatest story ever told.