Wednesday, February 25, 2009

Keeping an open mind on the mind-body problem, part 3

In my previous 2 posts on the mind-body problem (post 1, post 2), I criticized materialist philosophers -- that is, those who believe only the physical exists and thus deny the existence of any kind of mind distinct from one's physical body. As I said (quoting Thomas Nagel), one huge problem with this view is that "all materialist theories deny the reality of the mind," though they're usually not explicit about this point, possibly because very few normal people would accept their conclusion if stated plainly.

Here's Thomas Nagel's view, which I agree with:

To insist on trying to explain the mind in terms of concepts and theories that have been devised exclusively to explain nonmental phenomena is, in view of the radically distinguishing characteristics of the mental, both intellectually backward and scientifically suicidal.
Well, so far all of this has focused on the flaws with materialism. But is this just a negative point, or is there some positive, viable alternative?

I think so, but it requires accepting the fact that we probably don't have a satisfying theory yet. There's That's no reason to assume we'll never have such a theory. [UPDATE: I changed it from "There's" to "That's" because I realized I didn't want to make such a firm statement. Colin McGinn argues that, indeed, we'll never have a good theory.]

Here's Nagel's extended argument to this effect (this is all from chapter 2 of The View from Nowhere (1986), which is one of the best philosophy books I've ever read):

1. "The shift from the universe of Newton to the universe of Maxwell required the development of a whole new set of concepts and theories.... This was not merely the complex application, as in molecular biology, of fundamental principles already known independently. Molecular biology does not depend on new ultimate principles or concepts of physics or chemistry, like the concept of field. Electrodynamics did."

2. Even if these new, disparate concepts have been "superseded by a deeper unity,"* we wouldn't have been able to discover that "deeper unity" in the first place "if everyone had insisted that it must be possible to account for any physical phenomenon by using concepts that are adequate to explain the behavior of planets, billiard balls, gases, and liquids. An insistence on identifying the real with the mechanical would have been a hopeless obstacle to progress, since mechanics is only one form of understanding, appropriate to a certain limited though pervasive subject matter."

* Nagel suggests that this has actually happened; I don't know enough about the relevant science to have an opinion on that.

3. "The difference between mental and physical is far greater than the difference between electrical and mechanical."

4. If you believe that something can be "pervasive" but "limited," to use the words from point 2 -- and it's hard to see how anyone could deny this possibility -- then you should be open to the view that the physical isn't necessarily the only thing that's real, but rather is "only one form of understanding."

5. Given that it certainly seems like the world includes not just the physical but also the mental, "[w]e need entirely new intellectual tools, and it is precisely by reflection on what appears impossible -- like the generation of mind out of the recombination of matter -- that we will be forced to create such tools."

6. It's possible that if we go down this road and come up with a successful theory of the mind, we will not arrive at dualism, but will discover some sort of "deeper unity" of the mind and body. Nagel elaborates on this point:
In other words, if a psychological Maxwell devises a general theory of mind, he may make it possible for a psychological Einstein to follow with a theory that the mental and the physical are really the same. But this could happen only at the end of a process which began with the recognition that the mental is something completely different from the physical world as we have come to know it through a certain highly successful form of detached objective understanding. Only if the uniqueness of the mental is recognized will concepts and theories be devised especially for the purpose of understanding it. Otherwise there is a danger of futile reliance on concepts designed for other purposes, and indefinite postponement of any possibility of a unified understanding of mind and body."
I completely agree with Nagel on all this, and I try to keep it in mind anytime I read or hear overly confident materialist philosophers.


LemmusLemmus said...

Two quick points late at night; maybe more later:

The validity of your point 4 seems to depend heavily on how exactly the two italicized words are defined.

On point 6 in particular: I thought the party line among neurologists who have tackled these issues was that what we experience as our minds/consciousness/self was not itself made of physical matter but that the experience of consciousness/self/whathaveyou emerges as a result of physical processes. What is obvious is that many alterations of subjective experience can be explained as a result of changes in brain chemistry (e.g., drinking alcohol).

John Althouse Cohen said...

not itself made of physical matter but that the experience of consciousness/self/whathaveyou emerges as a result of physical processes. What is obvious is that many alterations of subjective experience can be explained as a result of changes in brain chemistry (e.g., drinking alcohol)

If that's correct -- that is, if it's true that our mental states are not "made of physical matter" but are merely "result[s] of changes in brain chemistry," then that suggests that materialism is incorrect, and Nagel is on the right track.

Nagel isn't doubting that things that happen in the brain cause things to happen in the mind. For instance, I'm pretty sure he doesn't believe in an afterlife and believes that when someone dies, the cessation of brain activity causes the end of all mental activity. He's just disagreeing with those who say that there is nothing distinctly mental in contrast with the physical brain, whether it be a distinct substance or even a distinct property.

LemmusLemmus said...

I'd put the bit you quoted in the materialist camp - but that's pointless haggling over definitions. (Belief in consciousness without brain activity would be clearly dualistic.)

I was referring in particular to two books by German neuroscientist Gerhard Roth, but according to Amazon, they haven't been translated into English (although there is this and this). Shame, good books.

John Althouse Cohen said...

You're mistaken. Materialism means only the physical exists. Dualism means there are mental states in addition to physical states (though they may be just different properties of the same thing).

It's about what kinds of things exist, not about whether they have causal effects on each other.

You're right that someone who believes in the existence of consciousness disconnected from any brain activity would also be a dualist (assuming they believe there are also physical things in the world). But that's not the only kind of dualist. You're simply dismissing the existence of interactionist dualists.

LemmusLemmus said...

Have followed your link and learned quite a bit (thanks!). I don't think that the position I sketched in the first post is best described as interactionist; rather, it seems to me it is best described as epiphenominalism (which also is a form of dualism; I stand corrected). I wonder, though, whether some of the people I referred to above would not prefer biological naturalism if pressed.