Over at Dr. William Vallicella’s Maverick Philosopher website there is a dicussion thread underway, prompted by a silly item in the New York Times about cognitive neuroscience and the soul. In the original article, the author, obviously unfamiliar with the labyrinthine convolutions of mind-body philosophy, embarrasses herself with the following:

But as evolutionary biologists and cognitive neuroscientists peer ever deeper into the brain, they are discovering more and more genes, brain structures and other physical correlates to feelings like empathy, disgust and joy. That is, they are discovering physical bases for the feelings from which moral sense emerges — not just in people but in other animals as well.

The result is perhaps the strongest challenge yet to the worldview summed up by Descartes, the 17th-century philosopher who divided the creatures of the world between humanity and everything else. As biologists turn up evidence that animals can exhibit emotions and patterns of cognition once thought of as strictly human, Descartes’s dictum, “I think, therefore I am,” loses its force.

I winced when I read this. As Bill V., an unrepentant dualist, correctly points out, it is the purest hogwash. It is so incoherent that, as scientists often say of a poorly organized hypothesis, “it’s not even wrong”.

That we are deepening our understanding of how our brains bring about our minds — and learning that other animals may perform some of the same tricks — undermines not in the least Descartes’s cogito, which is simply a demonstration by the mind, to the mind, that the thinker exists.

The aspect of Descartes’s model that is almost universally rejected among scientists these days is his assumption that the mind is a “substance” unto itself, capable of independent existence, and that it is in this nonmaterial substance that all our reasoning, decision-making, hoping, fearing, hypothesizing, and, of course, doubting, take place. The Mind, in this dualist model, then exerts its Will upon its puppet body in some unknown way; Descartes speculated that the point of entry might be the pineal gland.

The way that all this actually happens in the brain is now at the convergent focus of a number of scientific disciplines, equipped with brand-new tools of amazing power and resolution, and as has been the case in so many other areas of scientific inquiry, much that was previously regarded as ineffably mysterious is beginning to be understood as explicable natural phenomena. The manner in which the physical processes of the brain result in subjectivity itself is still outside the circle of illumination, but that we have not yet explicated how the trick is done is not in itself evidence for interactionist dualism, any more than not understanding the physics of lightning was evidence that thunderbolts were hurled by Zeus.

However, there is still deep resistance on the part of many philosophers, such as Dr. Vallicella (and Titus Rivas, whose paper on epiphenomenalism we looked at here and here, and will return to in a forthcoming post), to the idea that our subjective awareness can be the product of, or an aspect of, our material brains. In a comment in the thread linked to above, Dr. Vallicella says:

There is this incredible naivete on the part of science writers and most neuroscientists. They don’t think about what a correlation is or proves. A correlation is not an identity. To establish a correlation presupposes the distinctness of what is being correlated. And the correlations are consistent with substance dualism.

Yes, to establish a correlation is to presuppose the distinctness of what is being correlated, but that is often merely a first step toward a deeper synthesis that establishes that the correlated concepts have as their referent the same underlying phenomenon. For example, consider the commonplace phenomenon, familiar since time immemorial, that we call “heat”. As we delve into its physical underpinnings, we find that there is always a correlation between the state of motion of a physical object’s individual molecules, and how “hot” the object is. “Well, that’s all very interesting,” one might say, “but all you have done is establish a correlation; you still haven’t told me where the ‘hotness’ comes from. Indeed, the very fact that you establish a correlation between ‘heat’ and molecular kinetic energy presupposes that they are philosophically distinct.”

But this is misguided, of course; heat simply is molecules in motion. Scientific inquiry often begins with correlation and ends up establishing identity; it’s commonly the way our understanding of nature advances. Time and again in the history of science correlations have led investigators to deeper, more fundamental symmetries, to the realization that apparently disparate phenomena are in fact merely different aspects of a single natural entity.

Another example: to the ancient Greeks, the morning star, Phosphorus, and the evening star, Hesperus, were distinct objects. We might imagine observing that changes in the appearance of one were always correlated with changes in the other, and argue that there is some supernatural influence that passes between them: but pace Dr Vallicella, it turns out that they are one and the same object, namely the planet Venus.

Might substance dualism be true? Yes, perhaps it might, though the only reason to think so is that we have yet to understand the nature of subjectivity; and one can hardly be blamed for seeing it as just another “god of the gaps” spackle-job. Dualist philosophers simply declare that material systems cannot possibly be conscious, or intentional (as if they were already in possession of an exhaustive understanding of what “mere” matter is and is not capable of), and then adduce that “fact” as evidence for their position. Is there any justification whatsoever for considering mind-body dualism the only respectable postion, and for saying that to assume otherwise is “incredible naivete”? Of course not. It really does get downright tiresome and unhelpful after a while.

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  1. “Is there any justification whatsoever for considering mind-body dualism the only respectable postion”.

    Nooooo, but neither, I suspect, from a position of nil expertise, is the opposite. Should we not agree that before any decision on their respectability is taken, we should observe their future table manners?! Or, to bombard you with metaphors, are we not talking chicken and eggs here, or perhaps, ‘we’ve got a hung jury’?

    To be slightly more serious, are we not discussing a boundary problem, something akin to when exactly a gas becomes a liquid, or a liquid becomes ice?

    Posted July 1, 2007 at 3:07 pm | Permalink
  2. Malcolm says

    Hi David,

    Well, you are right, at least in our present state of knowledge. Phlogiston was a respectable account of heat until patient inquiry put it to rest, and likewise, interactionist substance dualism is not excluded at the moment either. What I object to is that while I cheerfully, if skeptically, admit that dualism is still a live option, those in the other camp seem rather less accommodating.

    A boundary problem? Perhaps, though I don’t think there is a sharp boundary at the frontier of consciousness.

    But yes, let’s see where further investigation takes us.

    Posted July 1, 2007 at 8:41 pm | Permalink
  3. Indeed, the very fact that you establish a correlation between ‘heat’ and molecular kinetic energy presupposes that they are philosophically distinct.”

    But this is misguided, of course; heat simply is molecules in motion. Scientific inquiry often begins with correlation and ends up establishing identity; it’s commonly the way our understanding of nature advances.

    One approach to this issue that occurs to me is that the difference between a correlation and an identity has to lie in the extent to which there are aspects of the items being related that do not correlate with each other.

    For example, in the case of heat, not only is there no case observed where an increase in heat content is not matched by a definite increase in molecular motion, we find that all the mechanisms by which heat is added to an object are mechanisms that increase the amount of molecular motion, and all mechanisms by which heat escapes an object are mechanisms by which molecular energy is transferred elsewhere.

    In the case of the mind/brain problem, the hypothesis we’re working with is that all the phenomena we associate with our mind relate to physical mechanisms in the brain, and there are no phenomena associated with the mind which lack a matching mechanism in the brain.

    Proving this either way won’t be easy, of course. Even if we undertake to build a computer with structures that perfectly mimic the brain, if the result doesn’t behave like a mind, all that means is that we’ve overlooked some piece of some mechanism somewhere. (Of course, if the result passes the Turing test, that opens a whole ‘nother can of worms.)

    Posted July 12, 2007 at 8:51 pm | Permalink
  4. Malcolm says

    Welcome, Karl, and thanks for that astute comment.

    This is indeed a very important point, and is at the heart of the idea of the “irreducibility” of consciousness. It has been raised often, at Bill Vallicella’s and elsewhere; the argument usually is of the form “Well, you can come up with as detailed a material description as you like! However we can still imagine all that material activity taking place, but without any consciousness, so you haven’t really explained consciousness at all.” This view actually goes one step further than what you are asking for (which was just the making of an exhaustive mapping between mental phenomena and brain activity); it even accepts that such a mapping might be possible but still have something left over. David Chalmers, for example, has taken this stand.

    I think that this assumption (that the fact that we can conceive of a brain doing everything that a conscious brain does without actually being conscious means that consciousness is not exhaustively accounted for by the brain) will probably turn out to be wrong. In other words, I think that it will turn out that whenever certain physical conditions are met (and the one place we can be confident they are actually met is in the functioning, biological human brain), consciousness must, lawfully, be present. Indeed it may be, pace Titus Rivas et al, that consciousness is simply a self-reflective “property” or “aspect” of certain sorts of matter, suitably organized. We do not yet know in virtue of what it is that matter may become conscious, but to toss in the towel and simply declare the case closed in favor of interactionist dualism is altogether unwarranted at this early stage of our scientific inquiry. The complacent confidence with which some philosophers say things like “mere matter cannot be conscious” is, to me, astounding — do those who say this imagine that we already know, exhaustively, what matter can and can’t do or be, or for that matter, what consciousness even is?

    Finally, dualistic models that simply posit an independent, mutually interacting conscious substance add no explanatory power at all; they offer no clarifying account of consciousness, other than to insist on its divorce from the material.

    Posted July 12, 2007 at 11:59 pm | Permalink