1. Minds and Bodies

2. Two possibilities:
Monism: the view that the world consists of one kind of thing
Substance Dualism:
The view that the world consists of two distinct kinds of things, minds and bodies.

3. Descartes is a substance dualist
Descartes is a substance dualist. He believes that there are minds and bodies are distinct kinds of things.
They are characterized by distinct properties
The mind is characterized by thought
The body is characterized by extension

4. Alternatives to dualism
A materialist holds that everything is physical. What we call “mind” or “thought” is understood in terms of physical processes (probably in the brain)
An Idealist holds that the world is mental or mind dependent.
Material objects are understood in terms of conscious experience.

5. Descartes argument for dualism
Whatever can be understood as distinct really is distinct
We can understand the mind without the body
We can understand the body without the mind
Therefore there is a real distinction between mind and body.

6. Is it true that we can understand our minds independently of anything physical?
Is it true that whatever we can understand as distinct is really distinct?
Lightning is identical to an electrical discharge, but it was a scientific discovery that these “two” things were really one.
Could the same be true of mind/body?

7. Another argument for dualism
Physical things are spatially extended (have a certain size, exist in space)
Minds have no spatial extension
Whatever is identical must have all properties in common.
Therefore minds and bodies are distinct things.

8. The Mind/Body Problem
Descartes is an interactionist dualist. He believes that there is causal interaction between minds and bodies.
When I move my hand my mind causes my body to move.
When I stub my toe, my body causes my mind to experience pain

9. It’s hard to understand how interaction is possible
It seems that when two things causally interact, they must share a common medium, they must be able to “meet up” somehow
One billiard ball can cause another to move only because they are both in space and can touch each other
The Moon and Earth do not touch, but they share the medium of space. Even “action at a distance” presupposes a common medium