What are the problems with the argument for the mind-body dualism from immateriality of thoughts?

Question

I have started studying philosophy of mind and I am currently reading an introduction to the field. The first topic that is presented in the book is dualism of the Cartesian brand, and the case for it is made, roughly, thus:

1. Material objects are characterized by such things as extension, shape, definite location in space and being made of elementary particles which could be described by a physical theory
2. Mental objects, such as sensations, perceptions and thoughts, exist
3. Sensations, perceptions and thoughts are not extended, have no shape nor definite locations in space, and are not made up of particles
4. Therefore, sensations, perceptions and thoughts are not material.

Honestly, it seems a good argument to me. If I think about a desire I am feeling, for istance, I could argue that it is my body, and so it would have a location in space, but it would not make sense to me to say that this desire has a shape, or that its position could be exactly pinpointed, or that it could be observed or detected through technological devices (even potentially!).

This notwithstanding, objections to the argument are not considered in the rest of the book. The only thing it has to say about dualism is that it demands an explanation of how the immaterial and the material interact causally. A lot more space is devoted to potential refutations of the knowledge argument, the zombie argument and the likes.

Even perusing some literature on the topic, the closest thing I have found to a discussion of this argument is in Smart's paper Sensations and Brain Processes. The author seems to argue, at least as far as I can grasp, that premise 2 is false: there is no such thing as a perception or a sensation or a thought, but only experiences of having a perception, or a sensation or a thought.

Besides this, I could not find references to the argument even in anti-materialist treatments (except for the book I'm studying, of course).

Why is this argument overlooked? Is it that bad?

Answer 1

This argument is a variation on what Kitcher calls the "rational psychologist's fallacy" in Kant's Transcendental Psychology. It is a particular case of the argument from ignorance fallacy, and was addressed already by Kant in Critique of Pure Reason. In the OP version of the argument the fallacious reasoning is rolled into using premise 3. Sensations, perceptions and thoughts are effects implemented by something, and one can not move from description of effects to conclusions about the nature of something that implements them, unless one actually knows how they can be implemented. So "not extended, have no shape nor definite locations" are no more relevant than the same statements about say heat or beauty.

In the original version of the fallacy sensations, perceptions and thoughts were replaced by "the unity of thought", and Kant pointed out that this sort of reasoning cuts both ways. Here is Kitcher's summary of Kant's argument in the Second Paralogism:

"If Rational Psychologists are permitted to argue for the simplicity and immateriality of the soul by claiming that they do not see how a material substance could realize the unity of thought, then materialists would be free to employ the same strategy to "establish" the opposite conclusion. Since the latter do not understand how an immaterial substance could realize the unity of thought, they may claim that the soul is material".

Here is another version of the same fallacy with immateriality replaced by intentionality, which is due to Searle:

"It is not because I am the instantiation of a computer program that I am able to understand English and have other forms of intentionality... but as far as we know it is because I am a certain sort of organism with a certain biological (i.e., chemical and physical) structure, and this structure under certain conditions is causally capable of producing perception, action, understanding, learning, and other intentional phenomena".

As Kitcher points out:

"In this passage Searle indulges in exactly the sort of argument from ignorance that Kant warns Rational Psychologists against... The problem with both arguments is that, although we have certain abstract descriptions of thoughts (they must be unified, they must be intentional), we do not have the slightest idea what kinds of things might be able to instantiate those properties. Proponents of such arguments disguise this fact, by announcing that souls possess the requisite unity or that brains possess the requisite intentionality. But these bold claims do not rest on an understanding of how anything could possess such properties; they are supported entirely by the antecedent conviction that it is brains or immaterial souls that do the thinking."

Answer 2

I think that argument would have been very effective a few hundred years ago. However, science has been clawing away at Premise 3. It is no longer immediately obvious that sensations have no shape or location, due to modern neurology. In fact, one might even dare to argue that premise 3 is obviously false. Consider that they check newborn's hearing within the first 24 hours by putting electrodes on their skull and playing soft clicks in their ear while recording the electrical activity. That strongly suggests there is a location to the sensation of hearing.

The focus on things like knowledge and p-zombies is more common because they are considered hard definitions to pin down. You think you know what knowledge is, until you really start to try to define it, and then you quickly realize that you know very little about how you know things. Likewise, p-zombies push at the definition of "consciousness" itself. They force us to ask question like "is consciousness even an observable property?"

The complicated part is when you start talking about mental processes supervening onto physical processes. It can get harder to tell whether something is a pure mental process, or if it is a physical process whose behavior is well described as though it were a metaphysical mental process.

Answer 3

Of course, sensations and other mental processes are not material. Electrochemical processes were unknown to Descartes. His characterization of res extensa derives from the restricted mechanical view of his time.

But when repeated today, the argument is a bit outdated: Today we say that mental processes are a kind of information processing, i.e. the basic term is information. Information processing always needs a material or better a physical substratum, e.g. nerve cells and the electrochemical processes of information processing. Information cannot be equated with these physical processes, but information presupposes the existence of these processes. A first bridge between physics and information theory is the concept of the entropy of a message. In the context of neuroscience this bridge has to be broadened to join physics and informatics and create a monistic and scientific view which incorporates mental processes.

Summing up: Descartes is right that mental processes are not material. But the scope of his approach is too narrow to be relevant for today's investigations.

Answer 4

What the problems in the argument are, and why it is overlooked, are two different questions.

1) Every argument has problems, so pointing out its problems does not explain why it is overlooked.

2) Is it really overlooked? I don't know. If people in this community do not come up with references I would appreciate if you could contact the author of said book with this question and let us know the answer here. (what is the name of the book?)

3) If it is indeed overlooked, then one possible explanation may be found in Peter Unger's recent bashing of philosophy:

What philosophers are in search of — and they don’t realize this — is generalizations that aren’t open to any conceivable possible counterexample, however far-fetched. These counter-instances don’t have to be at all realistic. So they put forth these offerings. Almost always, these offerings fail, and colleagues come up with counter-instances. When they don’t fail, they turn out to be trivial. Virtually all of them are analytically correct, though philosophers don’t realize it.

Generally, though, they’re mostly incorrect offerings, with counterexamples, and it keeps changing and keeps changing, until everyone becomes bored with the topic, and then they go on to something else. It’s not as though anything ever gets established, except for very trivial things, nor is it that anything ever gets refuted. Rather, things become old hat and fashions change. But this general way of doing things hasn’t changed. In about seventy or eighty years, as far as I can tell, in terms of mainstream English-speaking philosophy.

Answer 5

What is wrong with the proposition is that it has two mutually contradictory statements. If statement 2 is true, then statement 3 is false; if statement 3 is true, then statement 2 is false. This ensures that at least one statement,out of three, is false. Therefore, the conclusion is false.
This all comes about from the "normal" understanding of exist - an object exists, if it can be perceived by at least one of the 5 human senses.

Answer 6

Thoughts are not immaterial. Thoughts are neural activity, period. They do not float around in your head and are not dissipated or stored intact. They are neural "experiences" that can be replayed as "memories." They seem to be immaterial due to the brain's perception mechanism that we identify with as "self." "I" have this thought of "going to get ice cream." The "I" is also neural activity; self does not exist as an entity.