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Ideas escape from brain of pensive african man
Ideas escape from brain of pensive african man

Dualism Is Best Option for Understanding the Mind and the Brain

Theories that attempt to show that the mind does not really exist clearly don’t work and never did

Neurosurgeon Michael Egnor did a recent podcast with Arjuna Das at Theology Unleashed, “where Eastern theology meets Western skepticism.” In this section (with transcript), they talk about ways we can understand the relationship between the mind and the brain: The basic options are materialist (several varieties), idealist, panpsychist, and dualist.

The most popular textbook type theory is reductive materialism, which Egnor says argues that mental states are identical to brain states.

Here is a partial transcript and notes for the thirty to forty-two minute mark:

Identity theory

Michael Egnor: Identity theory doesn’t mean that mental states come from brain states or that they correlate with brain states but that they are brain states, in the same way that the evening star and the morning star are the same thing — the planet Venus just understood from different perspectives.

Of course, there are several problems with identity theory: One is that there is nothing about mental states that is the same as brain states. Brain states, for example, involve mass. They involve power, they involve weight, they involve dimensions, they involve chemistry.

Mental states involve feelings, beliefs, perceptions, intentions. There’s no crossover of the two Venn diagrams.

So to say that a mind-state is the same thing as a brain state is to violate what’s been called Leibniz’s Law. Leibniz’s law is that in order for two things to be identical, they have to be the same thing. (00:31:27)

The other reason why identity theory fails, from a philosophical perspective, is what I call the representation problem. You also call it the perfection problem. Here’s a good example:

Imagine a triangle. Don’t think of it in terms of a picture of a triangle but in terms of the definition of a triangle. A triangle is a plain figure, that’s closed with three sides. The sides are straight, and the internal angles add up to 180 degrees.

Now, imagine, can that concept be instantiated in a physical state? Is there any physical states imaginable that is perfectly flat, that has perfectly straight sides, and whose interior angles add up to 180 degrees? And the answer is, of course, no.

That is, any physical representation of a triangle, no matter how carefully you draw it, is not going to have perfectly straight sides, is not going to have exactly 180 degree angles. It’s not going to be exactly flat, even though from a mental state standpoint, those things are perfect. Therefore, the argument that a brain state is a mental state can not be true certainly of triangles, because a mental state of a triangle is a perfect state and a brain state of a triangle can never be perfect. (00:34:56)

Note: Identity theory “The earliest advocates of Type Identity—U.T. Place, Herbert Feigl, and J.J.C. Smart, respectively—each proposed their own version of the theory in the late 1950s to early 60s. But it was not until David Armstrong made the radical claim that all mental states (including intentional ones) are identical with physical states, that philosophers of mind divided themselves into camps over the issue.”“ – Stanford Encyclopedia of Philosophy

Another example would be logic. We’ll use modus tollens, that if A then B, not B therefore not A. So that’s a subtle logical validly, logical inference. However, there is no physical state in which relations between physical things follows modus tollens.

In a physical state of the brain you have electrochemistry, you have anatomical relationships, but none of the relationships in the physical brain have logical structure to them. So it makes no sense to say that a mind state is the same as a brain state when mind states encompass logic in brain states never encompass logic.

Note: Modus tollens – “For example, if being the king implies having a crown, not having a crown implies not being the king.” Wolfram Mathworld

In a physical state of the brain, you have electrochemistry, you have anatomical relationships, but none of the relationships in the physical brain have logical structure to them. So it makes no sense to say that a mind state is the same as a brain state when mind states encompass logic in brain states never encompass logic.


Michael Egnor: A second kind of materialist view of the mind–brain relationship is the idea that the only thing that is worth knowing — or can be known — about the mind is the relationship between the input to an organism and the output of the organism (behaviorism). And once you understand how organisms behave in response to inputs, you understand all there is to know about neuroscience. That is pretty clearly kind of a silly way to look at the mind because it leaves out the mind. It leaves out what goes on inside people.

I think it’s the only philosophical perspective that has been basically replaced by a joke. As the joke goes, two behaviorists are in bed after a night of passionate love, and one turns to the other and says, that was good for you, how was it for me?

And so behaviorism really kind of misses the important stuff in life and it’s just nonsense.

Note: Behaviorism seems like nonsense now but it was a big deal in the 1960s. Behaviorism “was a movement in psychology and philosophy that emphasized the outward behavioral aspects of thought and dismissed the inward experiential, and sometimes the inner procedural, aspects as well; a movement harking back to the methodological proposals of John B. Watson, who coined the name.” – Stanford Encyclopedia of Philosophy A cartoon expresses it: A rat is holding a sign that says “Will press lever for food.”


Michael Egnor: Functionalism is the idea that, basically, the mind is what the brain does. Materialists view mental states as basically the software and the brain state is the hardware. And the problem with functionalism, and particularly the computer functionalism model, is that if you look at the function of the mind as an algorithm, which functionalism naturally lends itself to, you cannot explain how meaning occurs in a thought.(00:38:09)

Algorithms never have meaning. That is, algorithms match an input to an output in accordance with a set of rules. But the meaning of the input and the meaning of the output are not a part of the system. A very good example of that is a word processing program. You can use a word processing program to type an opinion that you have, and then you can use exactly the same word processing program to type the opposite opinion. And the program doesn’t care whether you type yay or nay. Algorithmic processes are blind to meaning.

Another way of putting it is that they’re blind to semantics, they’re just syntax. So to explain the mind as an algorithmic process — which is what functionalism basically is — is to fail to explain how any thought can ever have a meaning. And if you leave meaning out of thought, you really don’t have much of a theory of mind. So functionalism is also a theory that doesn’t make any sense. (00:39:12)

Note: Precisely what computers don’t do is think. They only calculate. That’s why computers don’t really do creativity.

Eliminative materialism

Michael Egnor: There is also a third materialistic understanding of the mind: eliminative materialism. Eliminative materialists realized that identity theory, behaviorism, and functionalism don’t work. So eliminative materialists say the mind doesn’t exist. It is the only thing that exists is brain states. And we have foolishly thought that we have minds.

One can get into that rabbit hole rather deep, but it’s a pretty crazy way to look at things. It’s very hard to make a convincing case that you believe that there are no beliefs, which is basically what eliminative materialists are saying. So if someone tries to make an eliminative materialist argument, I think the best thing is just to move as far away as possible, just to get away from them.

Note: Odd as it may sound, eliminative materialism is a popular materialist philosophy, pioneered by the famous Daniel Dennett of Tufts University. Part of its attraction is that it eliminates the human mind altogether. That was perhaps summed up by controversial chimpanzee researcher Sue Savage-Rumbaugh: “Experimental psychologists typically assume that there is a major difference between ourselves and apes that is not attributable to environmental factors,” she said. “The difference in my work is that I never made that assumption.”


Michael Egnor: Idealism, I think is a highly respectable way of looking at the mind. What idealists say basically is that everything is mental and that even physical things are in their fundamental ontology mental things. And you can make a real case for that. And in the Christian tradition, the case has made that reality is a thought in the mind of God. And in that sense, I think you can make a very strong case for idealism and kind of a platonic idealism in which the Platonic world of forms really is God’s mind. (00:40:23):

Note: Idealism “the view that reality consists exclusively of minds and their ideas. Berkeley’s system, while it strikes many as counter-intuitive, is strong and flexible enough to counter most objections.” Stanford Encyclopedia of Philosophy


Michael Egnor: The viewpoint that I think makes the most sense is dualism. And the dualism that I think makes the most sense is Thomistic dualism, which is St. Thomas’s elaboration of Aristotle’s hylomorphism. There are other kinds of dualism, for example, Cartesian dualism and property dualism that I think are respectable. For example, Cartesian dualism has something to say for it. I think it’s a mistake. And I think the Descartes made terrible mistakes philosophically. But it’s worth looking at. And property dualism, I think has major flaws, but it’s not entirely crazy either. But Thomistic dualism, I think makes the most sense. (00:41:44)

I should also point out that I have some sympathy for panpsychism, the belief that everything has a mind. I don’t think it’s true that everything has a mind, but I think panpsychists have some insights that are worth recognizing.

Note: Dualism “In the philosophy of mind, dualism is the theory that the mental and the physical – or mind and body or mind and brain – are, in some sense, radically different kinds of thing.” – Stanford Encyclopedia of Philosophy

Just about any shallow science writer can tell you what is wrong with dualism, citing Descartes. But, in reality, the world we live in is inherently dual. There is classical physics and then there is quantum physics. There is material matter and energy and then there is immaterial information. just for example. Claiming they are all the same sort of thing is certainly a stretch.

Here are transcripts and notes for the first thirty minutes:

How we can know mental states are real? Mental states are always “about” something; physical states are not “about” anything. Michael Egnor argues that doing science as a physicalist (a materialist) is like driving a car with the parking brake on; it’s a major impediment to science.

Why neurosurgeon Mike Egnor stopped being a materialist atheist. He found that materialism is just not working out in science. Most propositions in basic science are based on mathematics and mathematics is not a material thing.


How science points to meaning in life. The earliest philosopher of science, Aristotle, pioneered a way of understanding it. Neurosurgeon Michael Egnor talks about the four causes of the events in our world, from the material to the mind.

You may also wish to read: Why the universe itself can’t be the most fundamental thing. Atheist biology professor Jerry Coyne is mistaken in dismissing my observation that proofs of God’s existence follow the same logical structure as any other scientific theory. (Michael Egnor)

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Dualism Is Best Option for Understanding the Mind and the Brain