Introduction to the Topic of Mind-Body Dualism
Mind-Body Dualism Many of our questions about brains, minds, and machines are not only questions for which we do not have answers, but questions for which we do not even have approaches for finding answers. What is consciousness? How could our three-pound brains possibly produce our rich experience of the world? Could a machine have subjective experience? These are the questions of philosophy of mind.
The Mind-Body Problem ❖
Five “obvious philosophical facts”: ❖
1. You have a mind and a body;
❖
2. These normally work together;
❖
3. Your body is physical and, thus, publicly observable;
❖
4. Your mental life is essentially private; therefore,
❖
5. You have privileged access to the contents of your own mind.
If the obvious philosophical facts are true, what must the universe be like? The simplest theory of the universe that fits these facts is Dualism.
To understand Cartesian Dualism…
❖
Crucial to the argument is a basic principle from Leibniz, the “indiscernibility of identicals”: ❖
1. If two things are identical—if two things are the same thing—then anything true of one is true of the other.
In groups answer the following questions: How does Descartes conceive of the essences of mind and body? According to Descartes, can a mind exist without a body? (Focus on the First and Second Mediation) ❖
The “indiscernibility of identicals”: ❖
If two things are identical—if two things are the same thing—then anything true of one is true of the other.
According to Dualism, the universe is divided into two radically different halves. ❖
1. The physical realm contains all those things made of matter, which occupy space and are governed by the laws of physics.
❖
2. The mental realm contains those things that are essentially mental: hopes, emotions, imaginings, and consciousness.
❖
3. A can of pineapple is entirely physical. The taste of pineapple is something mental.
❖
This position is Cartesian Dualism, outlined in Descartes’ Meditations.
Descartes offered logical arguments that Dualism must be true.
❖
The argument has two related conclusions. ❖
1. The first conclusion is that your mind is in no way the same thing as your body or any part of your body.
❖
2. The second conclusion is that what is essential to you is not your body but your mind.
When the pieces of the argument are put together, they entail the conclusion that Dualism must be true. ❖
Leibniz’s principle is: If two things are identical, everything true of one must be true of the other.
❖
I can doubt that I have a body or any part of a body. I can even doubt that I have a brain—maybe that is part of the illusion. I cannot doubt that I have a mind.
❖
There is, therefore, something true of my mind that is true of no part of my body: I cannot doubt that I have it.
❖
It follows by Leibniz’s principle that my mind cannot be my body or any part of my body. My mind cannot be my brain.
But dualism also has a central philosophical problem ❖
According to Cartesian Dualism, the mental and the physical are entirely different realms. One is a realm of things that obey physical laws and occupy space. Another is a realm of ideas, sensations, and feelings that don’t even exist in space.
❖
If those realms were entirely distinct, it would seem that nothing mental could cause anything physical, and nothing physical could cause anything mental.
❖
But we know that the mental does affect the physical: Our desires result in physical behavior. We know that the physical does affect the mental: Physical events in the world affect our beliefs and feelings.
❖
The “completely separate realms” view of Dualism must, therefore, be wrong.
Consider this thought experiment: ❖
We haven’t proven anything like this, but suppose the following beliefs turned out to be inconsistent. In order to remain consistent, you have to abandon at least one. Which of these beliefs would you keep, which would you reject, and why? ❖
a. The mental and the physical are radically different aspects of reality.
❖
b. The physical and the mental are causally linked.
https://www.youtube.com/watch?v=9QXI_BxlY7M
Phineas Gage Historical view of a number of things we have learned about minds and brains, starting with Phineas Gage. We should be able to find out things about the brain by seeing how the mind works. We should be able to find out things about the mind by seeing how the brain works.
Mind and brain seem to work together, yet we seem to have a single, unified stream of consciousness, despite the fact that different aspects of perception, judgment, and emotion are processed in different parts of the brain. How can that be?
