Philosophy

5

LECTURE: Eliminative materialism

We’ve now looked at various attempts by materialist philosophers to explain the most puzzling aspects of the mind, namely qualia, intentionality, and rationality. We’ve also looked at various objections to these attempts. Suppose these objections are sound. Suppose they show that the mind cannot, after all, be explained in materialist terms. What conclusion should we draw from that? One conclusion would be that materialism is false. That is, of course, the conclusion that dualists would draw.

But some philosophers draw a very different conclusion. They argue that, if the mind cannot be explained in materialist terms, that does not show that the mind is immaterial or non-physical after all. What it shows is that the mind does not really exist. If we can’t reduce mind to matter, then we should eliminate it altogether from our picture of reality.

Reduction versus elimination

The versions of materialism looked at so far – behaviorism, identity theory, functionalism, and computationalism – are reductionist forms of materialism. They all hold that the mind is real, but that what it really is is something other than what it appears to be. For the behaviorist, the mind can be reduced to patterns of behavior or dispositions for behavior. For the identity theorist, the mind can be reduced to a collection of brain states. For the functionalist, the mind can be reduced to abstract patterns of cause and effect. For the computationalist, the mind can be reduced to software. Again, none of these views deny the reality of the mind. They simply hold that the real nature of the mind is not what it seems at first glance to be.

Eliminative materialism is a much more extreme view. It says, not that the mind is real and that it is really just brain states, or really just a cause and effect pattern, or whatever. It says instead that the mind is not real, and that all that is real are the brain states, cause and effect patterns, or whatever. There are different ways you could spell this view out. You could take an eliminativist view about some aspects of the mind, but not others. For example, you could say that qualia are real and reducible to brain events, but that intentionality is not real and should be eliminated from our understanding of the mind. Or you could say that the mind as a whole is unreal.

The eliminative materialist’s favorite ZZ Top album

Eliminative materialism can be seen as a kind of “doomsday weapon” in the materialist arsenal. It is an extreme way to deal with the aspects of the mind that are difficult account for in materialist terms, when all attempts at reduction fail. It is a minority view – most materialists are not eliminative materialists – but materialists seem in general to want to keep it “on the table” as a possible view to take, perhaps in case no other way to save materialism ends up working out.

Churchland on the propositional attitudes

The most influential eliminative materialists are the contemporary philosophers Paul and Patricia Churchland. Here they are:

In the article you were assigned to read for this week, Paul Churchland focuses on arguing for an eliminativist position regarding intentionality, and in particular regarding what philosophers call the “propositional attitudes.” This is a technical term for mental states such as belief, desire, hope, fear, regret, and so on. The idea is that when, for example, you believe that the cat is on the mat, you are taking an attitude of belief toward the proposition or statement that the cat is on the mat; when you hope that the stock market will go back up, you are taking an attitude of hope toward the proposition that the stock market will go back up; and so on. Hence the label “propositional attitudes.”

The propositional attitudes are a key example of mental states involving intentionality. The belief that the cat is on the mat is about or points to the state of affairs of the cat being on the mat. The hope that the stock market will go back up is about or points to the state of affairs of the stock market going back up. And so forth. To explain intentionality in materialist terms would therefore require explaining propositional attitudes in materialist terms – for example, showing that beliefs, desires, etc. are really just dispositions toward behavior (as behaviorism would say) or really just brain states (as the identity theory would say), etc.

The propositional attitudes are a key element of what philosophers like Churchland call “folk psychology.” This is a fancy label for our ordinary, commonsense practice of interpreting, explaining, and predicting human behavior in terms of what people believe, what they desire, what they fear, and so on. For example, when you explain why Bob walked over to McDonald’s by saying that he desired to eat a cheeseburger, believed that McDonald’s would be the closest and cheapest place to get one, that he also desired to save time and money and therefore decided to go there, you are applying “folk psychology.”

Churchland thinks of folk psychology as a kind of theory. Like scientific theories, it explains what we observe (in this case, Bob’s behavior) in terms of what we don’t observe (his beliefs, desires, decision-making process, etc.).

Now, sometimes theories turn out to be correct. But sometimes they don’t. Sometimes they have to be abandoned. Churchland holds that “folk psychology” is a theory that may have to be abandoned. That is to say, he holds that it may be false to say that people have beliefs, desires, and other propositional attitudes that explain what they do. And one reason for this judgment is that it looks like it will be very hard for materialism to reduce propositional attitudes to brain processes, patterns of behavior, and so forth, given the problems we’ve seen critics raise against materialism.

Neuroscience or nothing

As Churchland understands eliminative materialism, then, it is the view that “folk psychology” is a false theory of human nature that cannot be reduced to neuroscience, and should therefore instead be eliminated and replaced by neuroscience. It’s not that beliefs and desires are real, and that what they really are is brain processes. It’s that beliefs and desires are not real, and that only brain processes are real.

No minds, only brains

What this means is that, in Churchland’s view, when you are describing human beings, only what you can put in the language of physics, chemistry, physiology, and neuroscience is real. If you can’t put in in those terms, then it doesn’t really exist.

If this doesn’t sound bizarre, then you haven’t understood it. It’s supposed to sound bizarre; or at least, Churchland would not deny that it is bound to sound bizarre. For Churchland, it is false to say that Bob went to McDonald’s because he desired a cheeseburger, believed he could get a cheap one there, etc. For there are no beliefs, desires, etc. Rather, the correct description would be to say that Bob went to McDonald’s because such-and-such clusters of neurons fired, such-and-such chemical secretions occurred in his brain, such-and-such muscles flexed, and so on. Only what can be described in that sort of physiological language truly describes Bob and his behavior. Talk about what he was thinking, wanting, etc. is at best a convenient fiction.

Hence, consider an ordinary event like people sitting on the beach and watching a sunset as waves crash on the shore. In his book Scientific Realism and the Plasticity of Mind, Churchland uses this as an example of how our ordinary description of what is going on is false, and of how an accurate description would make use instead of the language of physics and the other sciences. Of the people sitting on the beach in our example, he writes:

These people do not sit on the beach and listen to the steady roar of the pounding surf. They sit on the beach and listen to the aperiodic atmospheric compression waves produced as the coherent energy of the ocean waves is audibly redistributed in the chaotic turbulence of the shallows… They do not observe the western sky redden as the Sun sets. They observe the wavelength distribution of incoming solar radiation shift towards the longer wavelengths (about 0.7 × 10 - 6 m) as the shorter are increasingly scattered away from the lengthening atmospheric path they must take as terrestrial rotation turns us slowly away from their source. (p. 29)

He goes on in this fashion at some length, but that is enough to convey the idea. Again, for Churchland, only what can be described in terms of the technical language of the physical sciences is real. If you can’t put it in those terms, then it isn’t really there.

Baker’s critique

Now, a common objection to this sort of view is that it is not only bizarre, but ultimately self-defeating and incoherent. Eliminativists like Churchland unavoidably implicitly contradict themselves in the very act of trying to defend their positon. One philosopher who developed this criticism at length is Lynne Rudder Baker (1944-2017). Here she is:

Baker argues as follows. Eliminative materialists are trying to do two things. First, they deny that beliefs, intentions, etc. are real. Second, at the same time, they assert or claim that eliminative materialism itself is a true account of human nature, and the one that is most rationally acceptable in light of all the evidence. And the problem, Baker says, is that you can’t consistently say both of these things at once.

Here’s why. A statement counts as an assertion only because it expresses a belief that the speaker intends to express. For example, if I sincerely say “The cat is on the mat,” that counts as an assertion only if I believe the cat is on the mat (and am not merely uttering a line from a play, say) and intend to express this belief to you by saying it. Indeed, for a string of words to count even as a meaningful utterance at all (and not just meaningless noises) there has to be a thought that it expresses.

But then, if there are no thoughts, no beliefs, no intentions, then how can there be any assertions or meaningful statements? How could even a statement like “Eliminative materialism is true” be anything but meaningless gibberish?

Furthermore, consider what it is for something to be true. It is for it to represent the world in an accurate way, either in words or in thought. And thus, it involves intentionality – words and thoughts being about the world, pointing at the world, as it were. Moreover, the intentionality of words, as we’ve seen, derives from the intrinsic or build-in intentionality of thought. But if there is no intentionality, and there are no thoughts, then how can anything be true (or false for that matter)?

Or consider what it is for a view to be rationally acceptable. It has to do with one thought following logically from other thoughts. For example, we know it is rational to believe that “Socrates is mortal” because that follows logically from “All men are mortal and Socrates is a man.” But if there are no thoughts, then how can there be any such thing as “rational acceptability”?

So, if eliminative materialism really were true, then the very statement “Eliminative materialism is true” would not be a meaningful statement but just meaningless gibberish – in which case, it would not be true at all, any more than a meaningless string of marks like “ae#$lw&*1g+^” is true. The view is ultimately self-defeating.

A dead end?

Where does this leave us? On the one hand, for reasons like the ones we’ve been looking at for several weeks, materialism has a very difficult time explaining mental phenomena like qualia, intentionality, and rationality. And so it is very hard to defend materialism without falling into some version of eliminativism. And yet eliminativism appears to be self-defeating and incoherent.

On the other hand, because of the interaction problem, Cartesian dualism and property dualism have a very difficult time avoiding epiphenomenalism – the view that mental phenomena are just “along for the ride” and have no effect whatsoever on the body or on our behavior. And in that case it is, as we saw last week, difficult to see how we can even be talking about them. And yet we are. So, these forms of dualism too seem to be led into a self-defeating and incoherent position. What is going on?

Here’s one diagnosis. The source of the problem in both cases appears to be the conception of matter that arose with the “mechanical world picture” that defined itself against Aristotle’s commonsense understanding of matter. It is because the mechanical picture regards matter as colorless, odorless, soundless, meaningless, etc. particles, defined in purely mathematical terms, that it seems impossible to explain qualia and intentionality in material terms. It is because the mechanical picture drains qualia out of matter that Descartes ends up with the bizarre thesis that animals are unconscious automata. And it is because Descartes gets rid of Aristotle’s idea of the soul as the form of the body that he is unable to explain how the human mind can have any causal influence on the body (i.e. the interaction problem).

That suggests that the “mechanical world picture” has led philosophy of mind into a dead end, and that the solution might be to reverse course and return to the hylemorphic conception of the material world defended by Aristotle and Aquinas. And that’s precisely what contemporary neo-Aristotelian philosophers (though a minority position, to be sure) propose.

We’ll end our semester with a look at one further respect in which some materialists have claimed that our commonsense view about the mind should be abandoned – the idea that neuroscience has cast doubt on free will. We’ll look at an influential argument to that effect, and at Alfred Mele’s response to it, as discussed in his short book Free: Why Science Has Not Disproved Free Will.

In the meantime, here are some optional YouTube videos on our topic:

Patricia Churchland on Eliminative Materialism:

https://www.youtube.com/watch?v=vzT0jHJdq7Q

Eliminative Materialism:

https://www.youtube.com/watch?v=53k2k1sGPTk

Patricia and Paul Churchland on Consciousness:

https://www.youtube.com/watch?v=LpJSeLY8cWs

Patricia Churchland on Neurophilosophy:

https://www.youtube.com/watch?v=X2DPKLRBuio