Dualism is the philosophy of mind where the mind is nonphysical and independent of the physical brain. While the idea goes back as far as Zarathustra, it is Descartes’ formulation which is usually what we mean when we speak of dualism. Descartes believed that the mind is made of an immaterial substance and is the seat of consciousness, while the brain is where intelligence resides. Of course, this postulation of an immaterial substance accounting for the mind is without basis and, like the ether, never verified.
In researching what I hope will be an interesting blog on the placebo effect and ran across a paper by M. Beauregard. The same Beauregard that wrote a sophistry-laden book with Discovery Institute hack Denyse O’Leary called The Spiritual Brain (I refuse to provide a link to Amazon to legitimize that kind of dreary crap – the overview printed on the jacket alone was enough to make me nauseous). You can already see Beauregard’s bias in a review entitled “Effect of mind on brain activity: evidence from neuroimaging studies of psychotherapy and placebo effect.” The presumption that the mind is a separate entity from the brain is obvious from the title. He’s under the mistaken belief that phenomena such as the placebo effect can be explained by mind-brain duality. I suppose it can, but it is totally equivocal with the explanation that the mind and brain are inseparable.
Just because the two explanations are equivocal in and of itself doesn’t mean that dualism is wrong. Rather, it is the spectacular failure of dualism to explain certain other phenomena (which I will get to) that does. I find it difficult to believe that Beauregard is unaware of these problems and is being selective about where he invokes it to avoid having to deal with what I see are insurmountable problems for dualism. The problem for people like Beauregard is that while dualism and monism both explain phenomena such as the placebo effect, other phenomena, such as personality alterations following brain injury, can only be explained by monism.
Typically, scientists want to publish their papers in the most widely read journals as possible. Journals such as Cell, Journal of Neuroscience, Nature and Science are high on the list. The Journal of Alternative Medicine not quite so high. The usual modus operandi is to aim high, go next lower if it is rejected. So if you want an indication of where a paper stands in regards to the relevant scientific community, take a look at the journal’s citation index. To give an idea just how neuroscience views dualism, this paper was published in the Nordic Journal of Psychiatry. Yeah. Not exactly the Journal of Neuroscience.
Being an empiricist, I’m not swayed by purely philosophical arguments. That’s not to say philosophy isn’t useful. Science has little place in the arena of ethics, for instance, or art and literature (though more to say than most people think). But every philosophical argument for a position seems to have a counter argument. Sorry, philosophers, but wherever it is possible for science to have its say, I see it as the ultimate arbiter over such squabbling. When we don’t know the answer to a question, I don’t view philosophy as a solution – only a speculation awaiting verification. Too often and too easily philosophical arguments are destroyed by an ugly fact. Perhaps I shouldn’t say ‘too easily’, since the fact falsifying the argument isn’t always so easy to obtain. But once available, facts can be lethal to philosophy.
Dualism is no different. The ‘subjective argument in favor of dualism’, or the ‘argument from reason’, which is remarkably similar to Alvin Plantinga’s truly laughable ‘evolutionary argument against naturalism’ (something else I want to blog on), don’t hold any sway with me. But the worst argument for duality has got to be the ‘causal interaction’ argument, which invokes a miracle to explain all mind-body interactions. On the face of it, it is the parsimonious explanation for mind-brain duality, but it is really the laziest. Seriously, I have no words with which to convey my contempt for such an argument. It is lazy because it invokes a whole host of unsubstantiated requirements – that god exists, miracles happen, etc. It is indistinguishable from “I don’t know how the mind-brain interaction happens. It just does, so there!”
My first question for something where science can indeed have a say is, “What does the science say?” A lot, actually, and none of it bodes well for dualists. While this may sound like a philosophical argument, it is not – how can an immaterial mind interact with a physical brain? One of the most important parts of a scientific explanation is a demonstration of how, a mechanism of action. Without answering the ‘how’, there is no explanation. Descartes thought that the mind interacted with the brain through the pineal gland. But there is no reason why we shouldn’t take the liver over the pineal gland. Nor do Descartes or his followers give a mechanism of action and it simply begs the question. Dualism thus fails to give a mechanism for interaction with the brain, and thus also fails in providing a means for differentiating between mind-brain duality from a brain providing us with an illusion of a non-corporeal mind. If such an interaction occurs, we should be able to measure something in the brain that can only be explained via dualism. This is just not the case. If the mind is a product of the brain, no such problem exists for monists.
The second problem for dualists is the problem of deep personality changes following brain injury. If the mind and brain are separate, the mind is the seat of consciousness (and presumably personality) and the mind communicates with the brain only to pull the puppet’s strings, why would a brain injury alter who a person is? The classic case is that of Phineas Gage. In 1848, Gage was blasting rock to build a rail line when a charge prematurely exploded, sending the tamping rod he was using through his frontal lobe. Amazingly, he was conscious following the accident, but some time later, physician Dr. John Martyn Harlow wrote
The equilibrium or balance, so to speak, between his intellectual faculties and animal propensities, seems to have been destroyed. He is fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), manifesting but little deference for his fellows, impatient of restraint or advice when it conflicts with his desires, at times pertinaciously obstinate, yet capricious and vacillating, devising many plans of future operations, which are no sooner arranged than they are abandoned in turn for others appearing more feasible. A child in his intellectual capacity and manifestations, he has the animal passions of a strong man. Previous to his injury, although untrained in the schools, he possessed a well-balanced mind, and was looked upon by those who knew him as a shrewd, smart businessman, very energetic and persistent in executing all his plans of operation. In this regard his mind was radically changed, so decidedly that his friends and acquaintances said he was ‘no longer Gage.’
There are many similar examples of frontal lobe injury producing similar personality changes. How does duality explain such deep personality changes? It doesn’t, of course.
In a similar vein, if the mind and brain are independent, how do antidepressants work? LSD? A host of all sorts pharmaceuticals which alter personality? Again, duality can not explain this. But if “the mind is what the brain does“, as Stephen Pinker puts it, alterations of brain activity, through changes in neuronal metabolism or neurotransmitter release/uptake, are all that is necessary to explain why neuroactive substances also affect on the mind.
So, why do people insist on maintaining duality when the evidence from the neurosciences all points to a mind produced by the physical brain? First, we do have a strong illusion that the mind is separate from the brain. And it is a very strong illusion indeed. But that we simply perceive the mind to be independent of our body is not evidence that they are separate.
Second, it is necessary for certainly religious concepts. Here, I am thinking of the ‘soul’ and ‘free will’. I’ve always viewed the soul as a scientific explanation for the mind. A bad scientific explanation, to be sure. One for which there isn’t a shred of evidence for, and not for lack of looking. Douglas MacDougall attempted to determine if the soul had any weight (and failed). For anyone interested in a real explanation of the mind, I suggest Stephen Pinker’s How the Mind Works.
In the next segment I will lay some neuroscience on your ass and discuss what it has to say about ‘free will’.