1. Dualism

2. Popular Dualism
The Mind drives the body like a man in a tank.

3. Popular Dualism
It is presupposed by religious ideas of eternal life

4. Real Distinction Argument
P1. Whatever can be clearly and distinctly conceived apart can exist apart.
P2. Whatever can exist apart are necessarily distinct from one another.
P3. I can clearly and distinctly conceive my mind apart from my body.
P4. Therefore, my mind can exist apart from my body.
C. Therefore, my mind is necessarily distinct from my body.

5. Real Distinction Argument
P1. Whatever can be clearly and distinctly conceived apart can exist apart.
P2. Whatever can exist apart are necessarily distinct from one another.
P3. I can clearly and distinctly conceive my mind apart from my body.
P4. Therefore, my mind can exist apart from my body.
C. Therefore, my mind is necessarily distinct from my body.
A way of talking about the possibility of separation even where there is no such actual separation.

6. Real Distinction Argument
P1. Whatever can be clearly and distinctly conceived apart can exist apart.
P2. Whatever can exist apart are necessarily distinct from one another.
P3. I can clearly and distinctly conceive my mind apart from my body.
P4. Therefore, my mind can exist apart from my body.
C. Therefore, my mind is necessarily distinct from my body.
A consequence of the necessity of the non-separability of identical things.

7. Real Distinction Argument
P1. Whatever can be clearly and distinctly conceived apart can exist apart.
P2. Whatever can exist apart are necessarily distinct from one another.
P3. I can clearly and distinctly conceive my mind apart from my body.
P4. Therefore, my mind can exist apart from my body.
C. Therefore, my mind is necessarily distinct from my body.
A conclusion that Descartes reached in Meditations 1, 2.

8. Real Distinction Argument
He can’t be certain that bodies exist because the evidence for them is merely sensory, and the senses can be deceived.
The same possibility of error does not exist for the claim that his mind exists. (‘Cogito ergo sum’.)
So he exists as a thinking thing. But are mind and body distinct? Consider their essences.
The example of wax: the essence of the wax is extension (occupying space) and is known not through the senses but through ‘a purely mental contemplation’
the essence of Mind is thinking.
The fact that the idea of thinking does not entail the idea of extension or vice versa shows that the one cannot be a mode of the other.

9. Objections
He has not shown that he has a clear and distinct idea of the mind apart from the body.
He assumes that unless the concept of body is a part of the definition of ‘mind’ a complete concept of the mind is possible apart from that of the body
BUT
there might be necessary external relations between things that rules out having a complete concept of the one without the other. Eg. correlative terms like ‘parent’ and ‘child’

10. Objections
Excluding Body from my essence is just an intellectual abstraction
Compare thinking of something as being a right angled triangle but doubting whether the square of its hypotenuse was the sum of the squares of the other two sides.

11. Objections The argument is a fallacy.
p1. I can conceive of my mind as unextended.
p2. I can not conceive of my body as unextended.
c. Therefore my body and my mind are distinct.
BUT
p1. I can conceive of the evening star as being different from Venus.
p2. I can not conceive of Venus as being different from Venus.
c. Therefore the evening star and Venus are distinct.

12. The Argument from Divisibility
P1. The mind is indivisible.
P2. The body is divisible.
P3. If A is identical with B, then any property that A has B also has.
C. Therefore, the mind is distinct from the body.

13. Objections
It makes very good sense to talk about the parts of a mind or even of divided minds.
Certain cognitive functions depend upon the body, such as perception, memory.
Descartes equivocates upon the word ‘division’

14. Mind/Body Dualism Conclusion
Substance Dualism
The world consists of at least two types of thing, two substances, one of which is material and is essentially extended, and the other of which is mental and is essentially thinking .

15. Mind/Body Dualism Observations
Mind does not give life to the body
The soul does not dwell in the body like a pilot in a ship
Descartes says that the soul is ‘substantially united’ to the body, or ‘mixed up in it’.
a subtle fluid – the animal spirit – flows through the nerves and is the medium of communication between mind and body.
Mind Pineal gland Nerve fibres Limbs
Sense organs Nerve fibres Pineal gland Mind

16. Mind/Body Dualism Objections
The most common objection to substance dualism is that it is inconceivable that the two substances should be able to affect each other at all.
Responses
a. Occasionalism.
b. Pre-established Harmony.
c. Double-Aspect.
Descartes to Princess Elizabeth:  
I beg [Your Highness] to feel free to attribute this matter and extension to the soul because that is simply to conceive of it as united to the body.
Princess Elizabeth to Descartes:
I admit it would be easier for me to concede matter and extension to the soul than the capacity of moving a body and of being moved, to an immaterial being.

17. Mind/Body Dualism Objections
The most common objection to substance dualism is that it is inconceivable that the two substances should be able to affect each other at all.
There are objections to Dualism on the grounds of various conservation laws.
Ockam’s Razor. There is no increase in explanatory power provided by this new substance.
Scientific Psychology speaks against dualism.