Now Playing at a Cartesian Theater Near You: Dualism Returns

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We’re all intuitive dualists. It certainly seems that the world consists of two realms: the ordinary physical world of space and time and stuff; and the literally metaphysical (that is, beyond physical) world of the mind. Although this was undoubtedly everyone’s sense of things since the beginning of time, it’s now primarily associated with René Descartes, who articulated it in the 17th century, so it’s now known as Cartesian dualism. This immaterial realm is home to all metaphysical entities and forces (actually existing or not): the mind, soul, and spirit (whether or not these terms are synonymous); ghosts; God and the angels; Satan, devils, and demons; fairies, elves, and spirits; and fate, luck, destiny, and karma. Animals (according to Descartes) are purely physical beings, lacking both mind and soul, while people have both material bodies and immaterial minds.

Since the Age of Reason, however, secular, monistic materialism has become the dominant stance, in which reality (the world, the universe) consists of only one realm: the physical. (At least for the purposes of doing science. Some scientists who claim a belief in God assert that such belief isn’t incompatible with the principles of science.) Organisms, including human beings, are part of the physical world and biology is, at least in principle, reducible to biochemistry and ultimately to physics. In fact, as the science of psychology developed in the late 19th and early 20th centuries, the mind was banished, at first only methodologically (because introspection proved an unreliable and highly suspect foundation for a science) but in time philosophically as well. Remarkably, the science of psychology (etymologically, the science or study of the psyche—the mind) was redefined as behaviorism— the science of behavior only! Even today, in academia, behavioral science (or the behavioral sciences) is essentially synonymous with psychology.

Science, apparently, requires denying or at least ignoring the mind. Even if excluded as a subject matter, mind is central to a science. It’s impossible to explain science without mentalistic vocabulary: science develops theories to explain interesting (perhaps even puzzling or perplexing) observations. Doing science requires making decisions and judgments, justifying and defending ideas, and examining and evaluating the work of others. (It has been argued that quantum physics reintroduces mind to physical reality because the collapse of quantum uncertainty occurs only when an observer—presumably one with a mind— makes an observation. This seems unlikely. Did the universe, like the forest with the falling tree without anyone to hear, get by for almost fourteen billion years without suffering any quantum collapses because there were no physicists to observe them? And does a quantum system in a state of uncertainty know that the interfering photon is there to take a measurement and not just stopping by because it was in the neighborhood?)

Behaviorism was never an entirely comfortable stance. For all the trouble that philosophers, academic psychologists, and other scientists have with mind, we ordinarily accept its reality. Reports of pain and other sensory dysfunction are central to the diagnosis and treatment of injury, disability, and disease; hallucination, dreaming, and optical illusions are studied scientifically; and pain and pleasure are understood as real. (If not, faking an orgasm would hardly be possible.)

With the science of neurophysiology came a near-universal understanding that the mind is the result of activities in the brain. But mind itself continues to be a mystery—judging by the number of books, articles, journals, websites, societies, and YouTube videos attempting to explain it. Some philosophers (and cognitive scientists, an interesting phrase in this context) simply dismiss consciousness as just (!) an illusion. This is, of course, hijacking the word illusion, leading as it does to some paradoxical notions, such as the illusion of an optical illusion. And even granting that consciousness is an illusion, the illusion is still occurring—how? Where? To what or whom?

Nonetheless, science proceeded for about 300 years in a not uncomfortably materialistic stance. Dualism had, apparently, been eradicated. Then, starting around the middle of the 20th century, a new kind of dualism arose that’s still with us today. This modern version of dualism introduces a new metaphysical realm that might be called the computational or the cybernetic. This realm embraces not the computers themselves—which are mere physical entities (like the poor animals)—but rather the programs running on them. These programs escape the material world by manipulating something entirely ethereal—information. (Or data—in the computational realm, the two words are interchangeable.)

Cogito ergo sum (computer illustration)

The foundations for the modern computer were most notably laid down by Alan Turing, Alonzo Church, Claude Shannon, and John von Neumann. The fundamental idea is of a general purpose symbolic processor. (Such a device is now called a Turing Machine.) In this context, symbol doesn’t mean what it does in ordinary discourse—something endowed with significance or meaning, such as a fertility symbol, a sex symbol, a religious symbol, or a patriotic symbol. Here, symbol means an arbitrary sign that, by agreement, is understood to represent a particular idea or concept (its referent) and that can be mechanically manipulated using specified rules without regard to the meaning of that referent. For example, the numeral 0 is an arbitrary mark we’ve agreed represents the number we call zero. The numeral 1 is another mark, which we’ve agreed represents the number we call one.

We’re all so familiar with these symbols and how they’re used we overlook that they aren’t actually the numbers themselves but only their representations. But, for example, the arrangement of the numeral 1 followed by the numeral 0 can represent the number we call ten (in our familiar decimal number system), the number two (in the binary number system), eight (in the octal system), or sixteen (in hexadecimal). Conversely, we can represent the number ten using the numeral 1 followed by the numeral, the figure X (in Roman numerals), the letter A (in hexadecimal), and so on.”

In the physical, material world, there’s no inherent relation between a symbol and its referent—any more than that there’s a relationship between a Voodoo doll and the person it represents. The relationship is entirely a matter of social reality—our common cultural agreement. The information being processed by the computer doesn’t exist in a metaphysical realm any more than there’s an immaterial realm of football with entities like first downs and extra points. This is just as true when the numbers are represented by voltage levels in a computer as when they are represented by marks on paper or stone. That a voltage level in a computer file is carrying a bit of information is simply not an inherent physical property like charge, mass, or momentum. Like beauty, information is in the eye of the beholder.

To perform arithmetic or any other computation, we follow a set of rules that specify how to manipulate arbitrary symbols to achieve certain results. Because these rules can be followed mechanically— without any understanding of what they mean or why they’re being performed—they can be executed by a machine, such as a mechanical calculator or a computer. What’s happening in a computer is simply that a physical system in the material world is changing state. (And generating a lot of heat. As one wag suggested, a space alien visiting our planet might conclude that our computers were nothing more than heaters. The problem faced by space aliens examining our computers would be similar to that of SETI scientists: Whether an apparent signal is an actual one can be answered definitively only in the negative—by demonstrating a natural explanation for it.)

The notion of a cybernetic realm of reality separate from material reality has another metaphysical aspect: the computer program itself—not merely the information it’s understood to be processing—floats free of any physical reality, because it can be run on any computer, and so consists not in its material realization but in its ideas.

Although implicit from the very beginning of the computer era, the field of artificial intelligence (a coinage of computer scientist John McCarthy in 1956) introduced the notion that the mind wasn’t inherently a function of the brain, but simply information processing (the mathematical formula for this is brain/mind :: computer/program). In the early, heady, hubristic days of good old-fashioned artificial intelligence (GOFAI)—when the achievement of humanlevel artificial intelligence was said to be just around the corner (usually a little after, if not during the lifetimes of the people making the argument, at least their academic careers)—the position known as Strong AI held that a computer program passing the Turing Test would actually have a mind and would experience consciousness in the same way you and I do. (Interestingly, arguments for Strong AI were sometimes made by the very same people who asserted that, since there’s no way to observe consciousness directly, we don’t actually know that anyone but ourselves is really conscious. Then how could anyone tell whether a computer was?) Others (the connectionists) believed that a suitable computer simulation of the brain (implemented with artificial neural nets) would achieve liftoff. (But would it have free will?)

Skeptic 22.4 (cover)

This article appeared in Skeptic magazine 22.4
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Either way, this reintroduces a metaphysical realm beyond mere physical reality. Information— whether processed by the meat machine of the brain or the drier and far more elegant computer—resides in the realm of pure thought. (This has led at least one computer scientist to assert that the entire universe is a computer program, and another to propose that it’s likely we are living in a computer as simulations— the nerd’s version of the belief that we’re nothing more than ideas in the mind of God.)

The brain is not a computer and the mind is not a computer program. If you examine the neurons and the synapses of a living brain, you’ll find no bits—no arbitrary symbols with referents assigned by common assent. And neither the mind nor the computer program— an invention of that very mind—justifies a return to dualism. END

About the Author

Peter Kassan, over the course of his long career in software, has been a programmer, a software technical writer, a manager of technical writers and programmers, and an executive at a software products company. He’s the author or coauthor of several software patents. He’s been a skeptical observer of the pursuit of artificial intelligence and other matters for some time. He’s a regular contributor to Skeptic magazine.

About the image at the top

An illustration of the Cartesian theater. A tiny person sits in a movie theater inside a human head, watching and hearing everything that is being experienced by the human being.