Tuesday, February 03, 2015

Is it a mistake for Nagel to concentrate on reductive materialism?

I think some confusion is generated by his use of the term “reductionism” to describe the naturalistic position of which he is critical. Materialism is typically divided into three types, eliminative, reductive, and non-reductive materialism. On the face of things, by concentrating on reductive materialism, it might seem that he is letting the non-reductive materialists off the hook with his arguments, and this perhaps comprises the largest group of philosophers that call themselves materialist.
William Hasker, in The Emergent Self, (Ithaca, 1999), developed a tripartite definition of minimal materialism which, I believe works also for naturalism. That is, I don’t think any view can be thought to be genuinely naturalistic unless it satisfies these three requirements. And I think a position with these three characteristics is what Nagel is thinking of when he talks about reductive materialism. It is the view that
1)      At the basic level, reality is mechanistic. That is, it lacks intentionality, subjectivity, purposiveness, and normativity. None of these items can enter into a description of reality at the basic level of analysis.
2)      The basic level of analysis (which we typically call physics), is causally closed.
3)      Whatever else exists must supervene on the basic level. It must be the sort of think that must be the way it is because the physical is the way it is.

Andrew Melnyk maintains that “Naturalism claims that nothing has a fundamentally purposeful explanation…Naturalism says that whenever an occurrence has a purposeful explanation, it has that explanation in virtue of certain nonpurposeful (e.g. merely causal) facts.” And the failure to the mental on the ground floor of reality, so say that our minds can understand the world,  ultimately, because mind is fundamental to reality and not simply a byproduct of it, is what Nagel sees as ultimately wrong with the all the positions he is calling “reductivist.”

17 comments:

im-skeptical said...

"because mind is fundamental to reality and not simply a byproduct of it, is what Nagel sees as ultimately wrong with the all the positions he is calling “reductivist.”"

And he knows this by looking through his microscope and seeing the mentons darting about among all the other fundamental particles.

Victor Reppert said...

An interesting form of empiricism you have here.

im-skeptical said...

I'm simply pointing out that Nagel has no rational basis for believing that mind is a fundamental element of reality. This is something that people have a feeling about, but there is absolutely nothing in our observation that supports it, and plenty that points to its physical nature.

Benjamin Thompson said...

But again ims why should we think that we need observational evidence like what you are describing to make such an assertion?

This is especially true when Nagel is pointing to a similar problem in justification that we find in the problem of induction. That is, if the mind is completely reducible to the physical, then it seems that all thoughts and beliefs are caused by the physical. But if this is true then no belief that we have is truly caused from another belief but from something physical. Therefore the naturalists conclusion that the physical is all there is, is not produced by the evidence which he claims brought him to that conclusion but his particular brain states.

Ergo, on naturalism being rational seems impossible. No observational evidence is needed to draw this inference. It is based on what we know and experience about the brain and logic.

im-skeptical said...

"Ergo, on naturalism being rational seems impossible."

Can you say non sequitur? How do you make the logical leap from belief as a result of brain states to irrational?

Here is a definition of 'rational': based on or in accordance with reason or logic.

In other words, to be rational is to have reason to believe something, and especially, to have logical reason. You seem to make the assumption (as many theists do) that because the brain is a physical system, there's no reason for it to believe anything. That's bullshit. Brains are physical systems, and yet we do believe things with reason. And observational evidence tells us this.

Benjamin Thompson said...

That is a blatant strawman. I'm not simply saying that because brains are physical systems we have no reason to trust them. The argument is, if our brain states cause our thoughts then your belief that the physical is all there is was caused by a brain state not observational evidence. It is the idea that the thoughts produced by brain states are incidental to the brain states themselves. So if brain state A causes belief X but also causes brain state B and B causes belief Y then and so on and so forth there is no correlation between belief X and Y.

Saying that observational evidence tells you your mind is reliable is a non-sequiter. You can't, in principle, prove the reliability of your mind with observational evidence without assuming it is, indeed, reliable. The reliability of your mind must be assumed from the outset. But this also means that observational evidence cannot weigh in on the matter.

You might say from here that it must be just a brute fact that we have reason. Well that may be true, but that also doesn't undercut the argument. This is because it is also true that certain conceptions of the world would be inconsistent with the view that we are rational beings (able to use reason). The argument is that naturalism is such a conception. So if we know that our faculties are reliable, then we should abandon naturalism.

im-skeptical said...

"So if brain state A causes belief X but also causes brain state B and B causes belief Y then and so on and so forth there is no correlation between belief X and Y."
- under the theistic assumption that beliefs X and Y are somehow separate and distinct from brain states A and B. I don't buy your dualism.

"Saying that observational evidence tells you your mind is reliable is a non-sequiter."
- When did I say that? I said we believe things with reason, but not that everything we believe is based on reason. Clearly, our metaphysical beliefs about gods are irrational. The beliefs that are based on empirical evidence tend to be much more rational - and reliable.

"So if we know that our faculties are reliable, then we should abandon naturalism."
- So if we know that beliefs based on evidence are more reliable than beliefs unsupported by evidence, we should stick with the evidence. ;)


Benjamin Thompson said...

Actually I was assuming a sort of epiphenomenalism. But saying that belief X just is brain state A is even worse, because then you are just saying that our thoughts are electrochemical reactions. Thus any mental content to those beliefs is utterly illusory. Here, there may be a correlation between belief A and B but these "beliefs" are not really beliefs at all, but brain states.

When I say our faculties are reliable I mean that our faculties can reliably use reason, not that they necessarily use reason. So if our faculties are unreliable then that means that they cannot use reason reliably.

So if my brain state A is belief x, the question becomes; what tells me that brain states tend to produce reasonable or true beliefs? We might say that our beliefs are obviously reasonable, but that obviousness could itself be a delusion produced by our brain states. So, on naturalism, we still have a serious problem in justifying the reliability of our faculties.

im-skeptical said...

"the question becomes; what tells me that brain states tend to produce reasonable or true beliefs?"

A very good question. The answer is EVIDENCE. Unless we are arrogant, we don't simply postulate something, and then accept for all time that it must be true because we trust our ability to reason. We seek corroboration. We put it to the test. We try to prove it as many ways as we can. More importantly, we reject it if it fails to live up to scrutiny.

If your logical reasoning leads you to conclude one thing, and my logical reasoning leads me to conclude something different, how do we decide whether one or neither of us is correct? Evidence.

Victor Reppert said...

If mental states are physical states, then the truth about what someone believes should follow necessarily from the state of the brain/physical world. But it doesn't. If we line up all the physical facts, we have every atom traced, the argument from The brain is in state X therefore he must believe, say, that God exists, cannot follow necessarily. The state of the physical always leaves the state of the mental indeterminate. But what my thought is about is determinate, not indeterminate. Therefore my belief is not a physical state.

im-skeptical said...

"If we line up all the physical facts, we have every atom traced, the argument from The brain is in state X therefore he must believe, say, that God exists, cannot follow necessarily. The state of the physical always leaves the state of the mental indeterminate."

Who says?

Victor Reppert said...

Actually, that is what the arch-naturalist W. V. O Quine says.

im-skeptical said...

I haven't read Quine, but I understand he believed that there is no mental substance - mind is purely physical.

Victor Reppert said...

No, he's no dualist. But his position seems to be a version of eliminative materialism.

im-skeptical said...

This seem to be inconsistent with your statement above.

Dan Gillson said...

Donald Davidson, who described himself as a Quinean, nevertheless rejected what he called Quine's dualism of scheme and concept. Instead of having this kneejerk reaction to the word "dualism", Skep, perhaps you should ask what the dualism under question is a dualism of.

im-skeptical said...

"Instead of having this kneejerk reaction to the word "dualism", Skep, perhaps you should ask what the dualism under question is a dualism of."

I never used the word 'dualism' in connection with Quine. Perhaps you should pay more attention to the conversation instead of having a kneejerk reaction to whatever I say, Dan.