The mind is what the brain does?

I recently ran across this post by neurologist Dr. Steve Novella over at his blog Neurologica. The post is basically a rebuttal to neurosurgeon Michael Egnor’s views regarding how memory is encoded in the brain; however, my agenda here is not to comment on this exchange. Rather, this current post of mine was sparked by comments made by Dr. Novella in his post regarding the nature of the mind. Here’s some of what he had to say:

As I have pointed out numerous times myself – mental phenomena are functional active things. They are based in the physical substance of the brain, but they are not just the physical substance – they are what results from the function of the physical substance. The mind is what the brain does.

I’ve heard this theory of mind put forward many times; that is, the theory that the mind just is what the brain does. Note that this is not the same as saying that the mind is identical to the brain, rather it simply says that psychological states just are the products of neurophysiological processes. This theory is simply a type of identity theory. Identity theory is a type of reductive materialism and is defined, by the Stanford Encyclopedia of Philosophy, as the theory that “states and processes of the mind are identical to states and processes of the brain.” And this seems to be exactly what Dr. Novella’s position is, for he says that “mental phenomena (including memory) do not simply correlate with the firing of neurons in the brain – they are the firing of neurons in the brain.”

The first step that most materialists take towards justifying identity theory—or really any variation of a materialist philosophy of mind—is to provide evidence from neuroscience that demonstrates that the brain and mind are intimately related. And needless to say this evidence is not lacking at all. We know quite well that altering brain chemistry and brain structure can subsequently alter personality, can create a “divide” in consciousness, and can even cause individuals to fail to recognize familiar objects or even loved ones. There is no doubt that this says much about the correlation between the mind and the brain, but does is say any more than that by itself? Not really. Philosopher of mind James Madden, in his book Mind, Matter and Nature, articulates:

Has neuroscience revealed an empirical identity between psychological states and brain states? It clearly has not, nor does it seem that it ever could. What neuroscience does is to provide us with ever more precise descriptions of the goings-on in our brains that are correlated with our psychological states[…] Correlation is a far cry from identity; two phenomena can be perfectly correlated, without being identical. (p. 108)

The point then is that identity theory cannot be justified solely by the correlation between the mental and the neurological. As is commonly said, correlation does not imply causation. Now I maintain that not only can identity theory not be justified by pure findings from neuroscience, but I maintain that it is rife with ontological problems regarding actually accounting for how it is even possible that psychological states just are, and are reducible to, brain processes.

Intentionality and Necessary conditions

One of the first problems that identity theory runs into is accounting for intentionality. In philosophy of mind, intentionality refers to the ability of something to be about, or refer to, or represent something beyond itself. When I think of my wife, my thought is about, and refers to her. Now the problem here is that physical things only exhibit derived or secondary intentionality. The written word “cat” only refers to a cat if a mind so interprets it that way. It could just as easily have been the case that we endowed the word and utterance “cat” with a completely different meaning, or that another group of individuals takes the word or utterance “cat” to mean love. This means that physical symbols only have extrinsic intentionality and derive their intentionality from a mind that already exists. Now note that psychological states that exhibit intentionality do not borrow this intentionality from somewhere else. That is to say, our thoughts are not intentional because something external to us interprets them, rather they exhibit intrinsic intentionality, and thus our mental states constitute intentionality that is completely opposite the physical.

Now this posits problems for any philosophy of mind that is primarily materialistic. For how can a physical process be that which grounds intentionality if the physical first needs a mind in order to have intentionality at all? The materialist, then, needs a mind in the first place before he can start talking of intentionality being present in the physical. But the mind is the very thing the materialist is attempting to account for!

Furthermore, things get even worse for the identity theorist than this. Let us imagine a scenario where I raise my arm to a certain trajectory T1. Now let us say that I intended to raise my arm for some specific reason—perhaps to greet a co-worker. Now an identity theorist would say that my act of raising my arm can be accounted for in specifically neurophysiological events which terminated in certain muscular events which caused the raising of my arm. We can call this physical sequence that leads to the raising of my arm X1. Note that X1, by itself, is a sufficient condition for the raising of my arm to trajectory T1. So, the raising of my arm is therefore accounted for in completely materialist terms right? Not necessarily. For now imagine that instead of the physical sequence X1 causing T1, we say that this physical sequence is altered by only one neuron to cause a slightly different trajectory in my arm raising. So we can call this different physical sequence X2, and this new trajectory T2. So now we can say that X2 is a sufficient condition for the raising of my arm to trajectory T2.

But this is where we run into problems. While X1 might be sufficient for raising my arm to T1, and X2 is sufficient for raising my arm to T2, X1 and X2 are not necessary conditions for raising my arm as an intentional act. That is, in order to raise my arm as an intentional act, I do not need X1 or X2, but could have some other physical sequence obtain. But this means that no specific physical act is necessary for explaining the intentional act of raising my arm! Rather, while physical processes are sufficient for explaining my arm being raised in a certain specific manner, they are not sufficient for explaining my arm raising as an intentional act. Now note that if psychological states just are neurophysiological processes (i.e. if the mind is what the brain does), then certain physical sequences would be sufficient and necessary conditions for raising my arm intentionally. And since this is not the case then it cannot be true that our psychological states just are processes in the brain.

Rationality

A second problem that confronts identity theory is that of rationality. When certain neurophysiological states in the brain are followed by other subsequent neurophysiological states, neurologists understand exactly how these states follow from one another. If S1 (a neurophysiological process) is followed by S2, which is then followed by S3, it is the electrochemical properties of the brain, ultimately grounded in physical laws, that cause this transition. Now imagine that I entertain the following line of thought: 1) John is usually late to class on Mondays, 2) It’s Monday, 3) Therefore, John will most likely be late to class. Now notice that, on identity theory, each thought (each psychological state) will correspond to a certain brain state (neurophysiological process). But this means that if identity theory is true, then the cause of me inferring 3) from 1) and 2) is simply the electrochemical properties associated with those brain states.

This obviously runs into problems. For my act of inferring 3) was due to the semantics associated with 1) and 2), and I simply saw logically that 3) follows. And, in fact, for any inference or conclusion to be considered rational, it needs to be caused by the meaning and semantics of previous thoughts, or propositions. But, again, this is not true on identity theory. On identity theory it is not the semantics of 1) and 2) that cause the mental state of 3), rather what causes 3) is simply the blind electrochemical properties of the neurophysiological state associated with 2), which was caused in the same way by 1). But this type of causation is purely blind deterministic efficient causation. That is, it is simply matter dancing to the tune of physical laws, and therefore cannot be called rational in any sense. Thus stated, on identity theory any type of “rational inference” is, upon closer inspection, only pseudo-rationality, and therefore rationality as such is only an illusion.

Note that these are not the only devastating critiques of identity theory (there are others that I've put forth here and here). But I believe they go a long way in demonstrating that this reductive materialist theory of mind—that the mind is what the brain does—is vacuous. Now let it also be noted that the arguments above are not soul-of-the-gaps arguments. That is, the arguments are not saying “this or that aspect of cognition is difficult to explain currently, so we need to posit the soul or some Cartesian substance to account for them.” Rather the above arguments are ontological and deductive. That is, they don’t argue from current scientific ignorance, but instead argue that the ontology of a materialist theory of mind cannot ever in principle solve these problems. These problems then are a sort of reductio ad absurdum of materialism, and thus findings in neuroscience are irrelevant here.

In conclusion, then, we see that identity theory rests on a conflation of correlation with causation, and faces insurmountable arguments that demonstrate that the mind cannot simply be “what the mind does.”

Materialism, the intellect, and abstractions

Much of contemporary neuroscience, psychology and philosophy of mind take it for granted that the human intellect is wholly reducible to the material—namely, the brain. Neurologists have figured out that damage to certain parts of the brain can change a person’s personality, memory, and emotions.  And although neuroscience has much more progress to make, scientists are quite confident that the future of neuroscience will yield answers to our remaining queries. Yet I maintain that neuroscience will never in principle be able to account for many aspects of the human intellect, and it is one such aspect that I will be highlighting here: that of abstraction and the nature of abstractions.

Let me begin my point with an example. Let’s imagine that someone draws a circle on a chalkboard. Now I’ve seen a circle many times in my life before, and from the moment I first saw one I abstracted the concept of a circle from it, as we all did. And it is from our concepts of a circle that we constructed the definition of a circle. So, what is the definition of a circle? Well a circle is (in Euclidean Geometry) the set of points that are equidistant from a single point, i.e. the center. The question I would then pose is the following: does the circle that was drawn on the chalkboard satisfy the definition of a circle? The answer is not straightforward. For while we would indeed call the object on the chalkboard a “circle,” it does not actually satisfy the definition and concept of a circle. Why is this? Well, physical circles are never drawn with perfect curves—hence all points on a circle will not be exactly the same distance from the center--and therefore they will only ever be an imperfect or approximate participant in the definition of a circle.

Moreover, how do we know the figure on the chalkboard is meant to represent a circle, and not a hole, or a hoop? We cannot know until we ask the drawer of the circle, because only his concept of what he meant to draw is determinate. But even if the drawer did indeed mean to draw a circle, anyone could still mistake it for a hoop or a hole. Contrarily, my concept of a circle will always be a concept of a circle, and cannot be mistaken for the concept of a hole. 

Now, what does all this have to do with the human intellect? Well, the point is this. My concept of a circle is determinate, exact, and perfect, yet physical circles will only ever be indeterminate, approximate and imperfect.  So why is it that my abstractions and concepts of circles are the complete opposite of physical circles themselves? For if my thoughts and abstractions are simply material and physical processes, then why is their nature contrary to the physical and material? Could it be that abstractions and thoughts are not physical and material processes?

What we’ve discovered above applies to almost any physical or material representation or symbol. As philosopher Edward Feser notes in his book Aquinas:  material symbols and representations are inherently always to some extent vague, ambiguous, or otherwise inexact, susceptible of various alternate interpretations. (Another good example that demonstrates this point is that if one were to draw a one-thousand sided regular polygon (a chiliagon) and a one-thousand-and-one sided regular polygon, then we could not visually tell the difference between the two. Yet we can surely tell the difference between the two conceptually.)

Now, since the nature of the intellect is in complete opposition to the nature of the material, then we should be able to say that the former is not a process of the latter. That is, the human intellect is not the result of material processes like the brain. Thus, since materialism fails, in principle, to account for the nature of abstraction and the nature of the human intellect—the one thing we know best through introspection—we can safely regard it as inadequate.

Naturalism and falsifiability

Metaphysical naturalism is the position that the natural universe is all that exists, and a common corollary of adherence to naturalism is a subsequent adherence to physicalism—the theory that everything that exists is reducible to the material or physical. Such a metaphysical jump seems warranted: if the natural world is all that exists, and the natural world contains only the physical, then everything that exists is physical. These inferences illuminate exactly why naturalists are so enamored with science. For if all that exists is physical, and science studies the physical (empirical) world, then science surely must be the be-all and end-all road to knowledge and inquiry.

However, while the partnership of science and naturalism might seem like a match made in (non-existent) heaven, it quickly becomes riddled with problems. First, remember that science is very strictly committed to the doctrine of falsifiability. That is to say, something is considered to be a valid scientific hypothesis or theory if it could, at least in principle, be proven false. But, how does this view of falsification jive with naturalism? That is to ask, is naturalism itself falsifiable?  Well it might seem at first glance that this is indeed the case. For all one needs is evidence of the supernatural, and naturalism would subsequently be rendered invalid, right? Well, maybe not. Let’s examine a discussion between naturalist Richard Dawkins and Cardinal George Pell that illuminates where I’m going:

Moderator: What would it take [to convince you of the supernatural]?

Dawkins: I used to think that if somehow a great big giant nine-hundred foot high Jesus with a voice like Paul Robeson suddenly strode in and said “I exist, here I am.” Umm, but even that I actually sometimes wonder whether that would…

Pell: I would think you were hallucinating.

Dawkins: Exactly, I agree. I agree.

The point of this exchange is the following. Regardless of the fashion in which the supernatural (if it exists) would expose itself, such exposure could always be explained away in terms consistent with naturalism and physicalism. For instance, if Jesus or God were to appear to me, or to the whole world, this could always be waved away as a hallucination, or a prank by a higher life form in the universe. Now obviously the validity of such theories would be highly implausible, although the naturalist could claim that the opposite—that the supernatural was actually manifest—is equally implausible. Nevertheless, the point remains that naturalism is still salvageable despite apparent evidence to the contrary.

This all means one important thing: naturalism is, at least in principle, not falsifiable. I stress “in principle” because I believe that most logical people would abandon naturalism in practice were the aforementioned events to take place. However, my focal point here is principle. Now, since naturalism is unfalsifiable, then naturalism is unscientific, for remember that science only deals with the falsifiable. But this leads to a perfect irony. For if naturalism and physicalism are true then science and empirical observation are our only source of knowledge. Yet, because of such empirical considerations naturalism itself must be rejected. Thus stated, empiricism and naturalism do not pair together as well as is commonly claimed.