Mind, Purpose, and God (2)
A few hours on an airplane have given me a chance
to explore the papers in the Great
Debate more deeply than before.
The first three of them comprise an argument
by Andrew Melnyk that Mind is just physical, with a rebuttal
to that view by Stewart Goetz and Charles Taliaferro, and Melnyk's counter-rebuttal
in turn. The authors have called each other "M" for Melnyk and "TG" for
Taliaferro and Goetz. (I don't know why M didn't use "GT" instead of "TG;" but I
like the match with my own initials, since I certainly agree more with them than
with Melnyk.)
In his "Case for Physicalism about the Human Mind,"
M makes a case that mental events are all, in different forms and relationships,
representations. He says that mental
systems involve
sensors to
form representations about the person's environment and internal states, a means
to store
those representations and to
process
them interactively to produce behavior.
Humans' mental systems are unique in that they
can also generate "representations of states of affairs far removed... in time,
space or magnitude, representations of regularities in the world, and
representations of [their] own
representations."
What M doesn't tell us is just what is being represented to. Usually when we think of a something being represented, we think of a subject to whom it is being represented. For M, the person--or her mental states--seem just to be those representations. Representations happen, representations interact--but where, in M's system, is the person? Are we more than representations? Is there a screen on which the representations are displayed? If so, what is it? Is there anyone, any subject other than the system of representations, who is looking at it?
That's the first of my concerns with M's account of mind. TG don't seem to address that question in so many words. And quite charitably they overlook two places where M mixes up his assumptions and conclusions. The first:
"As far as we can tell, all human mental phenomena are dependent on neural phenomena; we never catch the human mind at work without also catching the human brain at work."
Part 2 of that sentence seems to be true. The first part is begging the question most unconscionably. The purpose of the paper is to show that all mental phenomena are dependent on neural phenomena; how can he so blithely toss that in as a premise, a point in favor of that argument? But it doesn't seem to be just a slip of the pen. The title of the section ("3.2 Evidence from the Neural Dependence of Mental Phenomena") states the same assumption, and he unfolds it further as follows:
"Since this dependence is best explained by physicalism about the human mind, it's evidence that physicalism about the human mind is true. In a nutshell, that's the reasoning of the present subsection."
One might hope, since this was just an introductory paragraph for a section of argument, that he might demonstrate that mental phenomena indeed depend on neural phenomena. The best he does, though, is to show that the two correlate with each other in time, and that there are physical brain correlations with certain mental phenomena. Logic 101 and Research 101 (regardless of the field) tell us, however, that correlation does not prove causation. He could come to that conclusion only by assuming it. Dualism (the contrary view to physicalism, saying that the mind is more than just physical) is entirely comfortable with this correlation. It acknowledges that mind is expressed in the physical world, and finds no reason to doubt that there is a physical locus for that interaction.
I wonder just how deeply M is immersed in his physicalism, and whether such immersion may have caused him to be blind to such an obvious begging of the question. I say this because he does it again not much later:
"The second reason why the dualist explanation of the neural dependence of the mental is inferior to its physicalist rival is that the dualist explanation is not only committed to the laws of physics... but also to a huge number of physically irreducible laws of nature connecting human mental phenomena to the human neural phenomena on which they depend."
Not only is he continuing to assume he can use his version of the dependence relationship as a premise in an argument in which he's trying to prove it, he's also assuming that the non-physical mind (on dualism) must be connected to the physical mind by "a huge number of ... laws of nature." I think that translates to this: the non-physical mind, which (on dualism) exists outside the causal nexus of laws of nature, participates in a huge number of laws of nature. Can M shake himself free of thinking in terms of laws of nature? He's trying to explain something about how mind must work if it is not part of nature, and he can only bring himself to think of it in terms of laws of nature. This hints at a lack of imagination, to say the least. It's also (again) question-begging.
I said that TG charitably overlooked these instances of question-begging. In truth, I think M actually could have just rephrased his statements, to make his intended point without committing this logical fallacy. TG deal with his intended argument, not this errant form of it. But it just leaves in me a niggling doubt regarding an author's frame of mind, that he could have failed to notice his assumptions sneaking in that way.
M thinks that physicalism is superior to dualism in that it explains the mind with fewer sets of assumptions. The laws of physics are all it takes, he says; but with dualism, "a divine creator who'd already created the associated neural phenomena would have to do extra creative work to produce mental phenomena." He does not tell us why he thinks that would bother the Creator, or why the Creator would have had to do it in just that order. The Biblical account is that God created humans in his image, which seems above all to mean that humans have minds and souls. This was a primary purpose for God, not "extra creative work" that he "would have to do." There is little if any force in this objection of M's.
Finally, M asks "could dualism about the human mind enjoy an advantage over its physicalist rival in explanatory power?" TG say yes, in their rebuttal here and in their opening argument in the second trio of papers. M says that science's track record of explanation counts as overwhelming evidence that its assumptions and methods will provide the explanation of mind that we want. TG point out (this is what I was alluding to above) that this is true only "if you have already eliminated all of the fundamental data of the mental that are not physical or physically realizable." In other words, M's physical explanations are adequate as long as you don't try use them to explain what they can't explain. As an example of that explanatory gap, TG write,
"If M is right, however, and physicalism is true, there is neither an ultimate and irreducible teleological explanation of your seeking to discover the answer to the question nor ultimate and irreducible mental-to-mental and mental-to-physical causation. There is neither of these because (in M's words) 'all human phenomena are dependent on neural phenomena.' (The emphasis is ours.) What this seems to imply is that everything that occurs in our mental lives, including our beliefs, is ultimately explicable in terms of physical causation alone without any explanation of that which is irreducibly mental by something else which is ultimately and irreducibly mental. If physicalism is true, it seems that the ultimate explanation of M's belief that physicalism is true will mention only neural phenomena and/or more fundamental physical constituents. There will be no mention in that explanation of anything that is ultimately and irreducibly mental. So, even if our first objection is answerable and there are irreducible contents of apprehensions and beliefs which are physically realized (which we doubt), physicalism entails that M believes that physicalism is true, not because his apprehensions of irreducible contents ultimately cause his belief with its irreducible contents but because physical (neural) realizers of those apprehensions causally produce physical realizers of that belief. In short, physicalism seems to entail that apprehensions of contents are explanatorily impotent and epiphenomenal. This is a hard pill to swallow. Given the truth of epiphenomenalism and the explanatory impotence of apprehensions of contents, why should any of us try to reason with others about anything with the hope of changing their beliefs by having them apprehend contents of conceptual entities?"
Though that's clear enough, I still feel a need to translate and/or summarize. M's system rules out a belief's being caused by the content of any thought, or any other mental state being caused by the content of another mental state. In his system it is strictly wrong for him to say he believes in physicalism because a prior thought--say, the extra work it requires God to do--led him to that conclusion. To repeat a key point from the above quoted paragraph, "it seems that the ultimate explanation of M's belief that physicalism is true will mention only neural phenomena and/or more fundamental physical constituents."
Another point from TG is also worth dwelling on: "physicalism seems to entail that apprehensions of contents are explanatorily impotent and epiphenomenal." By "apprehension of contents" they refer to our mental awareness of what our thoughts, beliefs, etc. are about. These are "explanatorily impotent." Our thoughts, beliefs, etc. have no explanatory power; they don't explain a thing. Your beliefs don't explain why you think what you think or why you do what you do, or why you draw conclusions to other beliefs. Things like these are epiphenomena, or phenomena--experiences, in a sense--that just ride along on top of what happens chemically and physically in our neural systems; they don't affect anything. That's the thrust of TG's point, and it seems quite robust to me.
Suppose someone asks you why you apply sunscreen before a day at the beach. You might answer, "because I believe it will protect me from pain, skin cancer, and wrinkles when I get older." You would probably consider that to be a true answer, an accurate explanation for why you use the lotion. M's system entails that this could never be a true answer, though, because you have used a belief about sun and skin to explain your behavior. Physicalism means that a belief is never an explanation for anything, including your applying sunscreen.
I suppose M could nod vigorously in agreement, and say "that's right; we only think our beliefs explain our behavior or our other mental activity, and it's really just an illusion." But M has drawn this conclusion, or so it appears, on the basis of his beliefs. He uses one set of beliefs to explain how he came to this conclusion, and why he thinks we should too--which is just what physicalism implies M (and we) cannot do. The system collapses in self-contradiction.
This is but one example of evidence that M must sweep aside if he's going to press his claim that physicalism can easily account for everything in our mental lives. (TG present more in their opening paper in the second round of debate, but I'll save that for another post.)
There's much more in this interchange that would be worthy of discussion if time allowed. In particular, I think M's counter-rebuttal, which is only addressed to one of several arguments brought forth by TG in their rebuttal, succeeds to some extent. He says TG cannot claim that introspection provides indefeasible support for their argument, that our self-perceptions by those means may be deceived. We could be victims of illusions. By physicalism, that is probably true. And yet how far can we go in that direction before we undermine all thought and rationality? I can't see anything stopping us short of the conclusion (under physicalism) that we can't trust any of our thoughts, any of our conclusions--including those of physicalism. So while he makes a successful point, he ought to be aware of just how successful it is: it's so successful that in the end it proves that the point can't be made after all, for all rationality is undermined.
And even if M's argument here were fully successful, it's aimed at only one of TG's objections, and not a central one at that. Most of what they wrote stands regardless of M's counter-rebuttal. I can't help but wonder why he did not address himself to more of TG's points, especially their point quoted here on the self-defeating nature of physicalism.
So obviously in my opinion TG make the better case in this round of discussion. It's a good debate, though, and a good start to a series that I trust will be interesting all the way through.
What M doesn't tell us is just what is being represented to. Usually when we think of a something being represented, we think of a subject to whom it is being represented. For M, the person--or her mental states--seem just to be those representations. Representations happen, representations interact--but where, in M's system, is the person? Are we more than representations? Is there a screen on which the representations are displayed? If so, what is it? Is there anyone, any subject other than the system of representations, who is looking at it?
That's the first of my concerns with M's account of mind. TG don't seem to address that question in so many words. And quite charitably they overlook two places where M mixes up his assumptions and conclusions. The first:
"As far as we can tell, all human mental phenomena are dependent on neural phenomena; we never catch the human mind at work without also catching the human brain at work."
Part 2 of that sentence seems to be true. The first part is begging the question most unconscionably. The purpose of the paper is to show that all mental phenomena are dependent on neural phenomena; how can he so blithely toss that in as a premise, a point in favor of that argument? But it doesn't seem to be just a slip of the pen. The title of the section ("3.2 Evidence from the Neural Dependence of Mental Phenomena") states the same assumption, and he unfolds it further as follows:
"Since this dependence is best explained by physicalism about the human mind, it's evidence that physicalism about the human mind is true. In a nutshell, that's the reasoning of the present subsection."
One might hope, since this was just an introductory paragraph for a section of argument, that he might demonstrate that mental phenomena indeed depend on neural phenomena. The best he does, though, is to show that the two correlate with each other in time, and that there are physical brain correlations with certain mental phenomena. Logic 101 and Research 101 (regardless of the field) tell us, however, that correlation does not prove causation. He could come to that conclusion only by assuming it. Dualism (the contrary view to physicalism, saying that the mind is more than just physical) is entirely comfortable with this correlation. It acknowledges that mind is expressed in the physical world, and finds no reason to doubt that there is a physical locus for that interaction.
I wonder just how deeply M is immersed in his physicalism, and whether such immersion may have caused him to be blind to such an obvious begging of the question. I say this because he does it again not much later:
"The second reason why the dualist explanation of the neural dependence of the mental is inferior to its physicalist rival is that the dualist explanation is not only committed to the laws of physics... but also to a huge number of physically irreducible laws of nature connecting human mental phenomena to the human neural phenomena on which they depend."
Not only is he continuing to assume he can use his version of the dependence relationship as a premise in an argument in which he's trying to prove it, he's also assuming that the non-physical mind (on dualism) must be connected to the physical mind by "a huge number of ... laws of nature." I think that translates to this: the non-physical mind, which (on dualism) exists outside the causal nexus of laws of nature, participates in a huge number of laws of nature. Can M shake himself free of thinking in terms of laws of nature? He's trying to explain something about how mind must work if it is not part of nature, and he can only bring himself to think of it in terms of laws of nature. This hints at a lack of imagination, to say the least. It's also (again) question-begging.
I said that TG charitably overlooked these instances of question-begging. In truth, I think M actually could have just rephrased his statements, to make his intended point without committing this logical fallacy. TG deal with his intended argument, not this errant form of it. But it just leaves in me a niggling doubt regarding an author's frame of mind, that he could have failed to notice his assumptions sneaking in that way.
M thinks that physicalism is superior to dualism in that it explains the mind with fewer sets of assumptions. The laws of physics are all it takes, he says; but with dualism, "a divine creator who'd already created the associated neural phenomena would have to do extra creative work to produce mental phenomena." He does not tell us why he thinks that would bother the Creator, or why the Creator would have had to do it in just that order. The Biblical account is that God created humans in his image, which seems above all to mean that humans have minds and souls. This was a primary purpose for God, not "extra creative work" that he "would have to do." There is little if any force in this objection of M's.
Finally, M asks "could dualism about the human mind enjoy an advantage over its physicalist rival in explanatory power?" TG say yes, in their rebuttal here and in their opening argument in the second trio of papers. M says that science's track record of explanation counts as overwhelming evidence that its assumptions and methods will provide the explanation of mind that we want. TG point out (this is what I was alluding to above) that this is true only "if you have already eliminated all of the fundamental data of the mental that are not physical or physically realizable." In other words, M's physical explanations are adequate as long as you don't try use them to explain what they can't explain. As an example of that explanatory gap, TG write,
"If M is right, however, and physicalism is true, there is neither an ultimate and irreducible teleological explanation of your seeking to discover the answer to the question nor ultimate and irreducible mental-to-mental and mental-to-physical causation. There is neither of these because (in M's words) 'all human phenomena are dependent on neural phenomena.' (The emphasis is ours.) What this seems to imply is that everything that occurs in our mental lives, including our beliefs, is ultimately explicable in terms of physical causation alone without any explanation of that which is irreducibly mental by something else which is ultimately and irreducibly mental. If physicalism is true, it seems that the ultimate explanation of M's belief that physicalism is true will mention only neural phenomena and/or more fundamental physical constituents. There will be no mention in that explanation of anything that is ultimately and irreducibly mental. So, even if our first objection is answerable and there are irreducible contents of apprehensions and beliefs which are physically realized (which we doubt), physicalism entails that M believes that physicalism is true, not because his apprehensions of irreducible contents ultimately cause his belief with its irreducible contents but because physical (neural) realizers of those apprehensions causally produce physical realizers of that belief. In short, physicalism seems to entail that apprehensions of contents are explanatorily impotent and epiphenomenal. This is a hard pill to swallow. Given the truth of epiphenomenalism and the explanatory impotence of apprehensions of contents, why should any of us try to reason with others about anything with the hope of changing their beliefs by having them apprehend contents of conceptual entities?"
Though that's clear enough, I still feel a need to translate and/or summarize. M's system rules out a belief's being caused by the content of any thought, or any other mental state being caused by the content of another mental state. In his system it is strictly wrong for him to say he believes in physicalism because a prior thought--say, the extra work it requires God to do--led him to that conclusion. To repeat a key point from the above quoted paragraph, "it seems that the ultimate explanation of M's belief that physicalism is true will mention only neural phenomena and/or more fundamental physical constituents."
Another point from TG is also worth dwelling on: "physicalism seems to entail that apprehensions of contents are explanatorily impotent and epiphenomenal." By "apprehension of contents" they refer to our mental awareness of what our thoughts, beliefs, etc. are about. These are "explanatorily impotent." Our thoughts, beliefs, etc. have no explanatory power; they don't explain a thing. Your beliefs don't explain why you think what you think or why you do what you do, or why you draw conclusions to other beliefs. Things like these are epiphenomena, or phenomena--experiences, in a sense--that just ride along on top of what happens chemically and physically in our neural systems; they don't affect anything. That's the thrust of TG's point, and it seems quite robust to me.
Suppose someone asks you why you apply sunscreen before a day at the beach. You might answer, "because I believe it will protect me from pain, skin cancer, and wrinkles when I get older." You would probably consider that to be a true answer, an accurate explanation for why you use the lotion. M's system entails that this could never be a true answer, though, because you have used a belief about sun and skin to explain your behavior. Physicalism means that a belief is never an explanation for anything, including your applying sunscreen.
I suppose M could nod vigorously in agreement, and say "that's right; we only think our beliefs explain our behavior or our other mental activity, and it's really just an illusion." But M has drawn this conclusion, or so it appears, on the basis of his beliefs. He uses one set of beliefs to explain how he came to this conclusion, and why he thinks we should too--which is just what physicalism implies M (and we) cannot do. The system collapses in self-contradiction.
This is but one example of evidence that M must sweep aside if he's going to press his claim that physicalism can easily account for everything in our mental lives. (TG present more in their opening paper in the second round of debate, but I'll save that for another post.)
There's much more in this interchange that would be worthy of discussion if time allowed. In particular, I think M's counter-rebuttal, which is only addressed to one of several arguments brought forth by TG in their rebuttal, succeeds to some extent. He says TG cannot claim that introspection provides indefeasible support for their argument, that our self-perceptions by those means may be deceived. We could be victims of illusions. By physicalism, that is probably true. And yet how far can we go in that direction before we undermine all thought and rationality? I can't see anything stopping us short of the conclusion (under physicalism) that we can't trust any of our thoughts, any of our conclusions--including those of physicalism. So while he makes a successful point, he ought to be aware of just how successful it is: it's so successful that in the end it proves that the point can't be made after all, for all rationality is undermined.
And even if M's argument here were fully successful, it's aimed at only one of TG's objections, and not a central one at that. Most of what they wrote stands regardless of M's counter-rebuttal. I can't help but wonder why he did not address himself to more of TG's points, especially their point quoted here on the self-defeating nature of physicalism.
So obviously in my opinion TG make the better case in this round of discussion. It's a good debate, though, and a good start to a series that I trust will be interesting all the way through.
Posted: Fri - August 10, 2007 at 06:14 PM |
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