Colin McGinn is particularly good in condemning materialist explanations of consciousness, pointing out that it's impossible to collapse the mind into the brain. Or, as he puts it: "[T]he mind is … meat neither more nor less." To the materialist the feeling of "pain, for example, is nothing more than a firing of certain fibers in the brain. The feeling of pain simply reduces to such physical processes. The two are not merely correlated; they are identical." To the materialist, Mr. McGinn continues, "the mind is the brain in disguise. The djinn is the lamp."
He goes on to point out that he could hypothetically "know everything about your brain of a neural kind …its anatomy, its chemical ingredients, the pattern of electrical activity in its various segments … the position of every atom and its subatomic structure … everything that that materialist says your mind is. Do I thereby know everything about your mind? It certainly seems not. On the contrary, I know nothing about your mind. I know nothing about which conscious states you are in … and what these states feel like to you..."one of my friends (let's call him/her X, given his/her request that his/her identity be preserved) wrote the following long response:
Actually, I think we would. When we lose neurons, or glial cells, for any reason, we lose our minds and in the process we lose ourselves. Recently someone told me about how their mother, who suffered a brain tumor, progressively changed in personality as the tumor grew and she deteriorated. Through cerebral injuries we can selectively lose our memories, our acquired knowledge (forgetting how to read or write), even our awareness of self (some people stop recognizing their bodies as their own), our inhibitions ... Dementia is a wonderful example of how as we lose neuronal firings we lose the mind, the essence of the person. Another example is how electrolyte imbalances have profound neurological effects from which we may never recover. I mean a sudden depletion of K, of Na or of glucose and how they can alter mental status. How can this loss of self be explained if the self is not the brain? If the self is somewhere else? ...
The more interesting question that this paper raises for me is, why does the author want so badly for the mind to be different from the body? If there is no difference, does it mean human experience doesn't matter? Does it matter less? In any case why do we experience the world of ideas as different from that of the material? Are we intrinsic dualists?I'm no neuro-expert, and I'm no philosopher either. But it seems to me that the materialist response, while entirely consistent with experiment and with everything we know about the brain so far, seems not to engage with Rosenbaum's interpretation of McGinn's philosophical issue. For the materialist, there is nothing other than the physical brain and its electroneurobiochemical state, from which the mind emerges. As I see it, McGinn's response is, "when you say 'the mind is the brain,' what does 'is' really mean?" (The typical philosophical response!)
But this really does conceal some issues here. For if the materialist means, "the mind is identical to the brain," then this is clearly false: the mind is not structured like the brain. Indeed, even though my mind can reflect upon itself, it has no awareness of its underlying brain structure; how could that be the case if it were precisely identical to a brain? However, as X says, what the materialist wants to say is "the mind is nothing more than the brain," so that there is nothing in the mind that does not relate to the brain quite directly. And X's examples show cases where alterations to a person's brain's state seem to alter that person's mind's state as well, sometimes quite permanently. Does this not utterly refute the philosophical case of the dualists?
[Full disclosure here: I'm not yet convinced that either position is the absolute correct.]
My friend's examples certainly prove that, as far as we can tell, there exist mental states derivable from brain states. (And I seriously doubt Rosenbaum or McGinn could dispute this.) However, this is not sufficient to prove the materialist argument, that all mental states derive from brain states. To do that, we would need to construct some sort of systematic and comprehensive mechanism by way of which every conceivable mental state can be mapped to a particular brain state (the converse not being necessary). And as far as I know, neuroscience is quite far from that point.
Here McGinn can raise a seemingly difficult problem: is this even possible? Can we really map every component of a typical mental state—every object I'm seeing, everything I'm smelling, every sound I can hear at this point, plus all the random thought floating through my head—precisely onto the brain's state at that point? This seems to be his claim when he states that even when he knows everything about a person's brain state, he cannot know their mind. But this is really less an argument about the distinctness of the mind from the brain than an argument about the existence of a mind-state --> brain-state mapping and its inverse brain-state --> mind-state mapping. The materialist is still safe so long as he or she can argue that such a mapping exists, even if its details are not fully fleshed out.
And I think there is a difficulty at that very point for the materialist: it seems to me that, contrary to its own claim, the materialist thesis cannot be experimentally verified. Why? Because a person's mind is not available to another for testing. We exist within our own minds, and we are conditioned by habit to think that other people's speech and actions are a window onto their thoughts, that their behavior is a reflection of their mind. But this is not strictly true. We can never really peer into somebody's mind and examine what's going on; if we could, psychologists would all be out of jobs.
As a result of this rather pedantic argument, X's examples are not as illustrative as X wants them to be—they prove that modifications to a person's brain state can modify that person's visible behavior, for that can clearly be observed, but they cannot prove that these modifications alter the person's mind-state, or that it is the person's altered mind-state that causes their altered observable behavior. This problem with the materialist thesis cannot be resolved by additional refinements to our knowledge of neuroscience, because it does not rely on an imperfect understanding of brain states. On the contrary, what it argues is that mind-states can never be truly observed or communicated in any manner, and hence cannot ever be truly mapped to brain-states. All that can be mapped are observable behaviors. [Note that this is not an argument about whether mind-states are distinct from brain-states, but one about whether we can ever know anything at all about mind-states.]
Now, the materialist may say that suffices. "How should it matter to me what my mind is thinking when I know that if I apply this particular level of electrical input to this particular neuron, I can consistently get my subject to sing 'Happy Birthday'?" From a clinical perspective, that's true. And it's quite possible to dismiss what I've said here as theoretical chatter that has no practical implications, or as pure sophistry. But from a philosophical perspective, it is not mere wordplay. Because all that we have managed to do is draw a sharp line between physical and mental events. We have not yet established if mental events do exist separately from physical events; indeed, we've made it all the more difficult for us to establish if they do exist at all! But we have not yet reconciled our phenomenological picture of the mind with the neurological picture, and there is as much philosophy here as there is biology.
Much more on this tomorrow. I'm still thinking about this issue, and I've not yet engaged with X's second paragraph at all. And these positions are all tentative, as always. I reserve the right to change my mind (or should I say my brain?) at any time.
Now, the materialist may say that suffices. "How should it matter to me what my mind is thinking when I know that if I apply this particular level of electrical input to this particular neuron, I can consistently get my subject to sing 'Happy Birthday'?" From a clinical perspective, that's true. And it's quite possible to dismiss what I've said here as theoretical chatter that has no practical implications, or as pure sophistry. But from a philosophical perspective, it is not mere wordplay. Because all that we have managed to do is draw a sharp line between physical and mental events. We have not yet established if mental events do exist separately from physical events; indeed, we've made it all the more difficult for us to establish if they do exist at all! But we have not yet reconciled our phenomenological picture of the mind with the neurological picture, and there is as much philosophy here as there is biology.
Much more on this tomorrow. I'm still thinking about this issue, and I've not yet engaged with X's second paragraph at all. And these positions are all tentative, as always. I reserve the right to change my mind (or should I say my brain?) at any time.
