Cartesian DualismCartesian Dualism

Real Distinction ArgumentReal Distinction Argument

P1.P1. Whatever can be clearly and distinctly Whatever can be clearly and distinctly conceived conceived apart can exist apart.apart can exist apart.

P2.P2. Whatever can exist apart are Whatever can exist apart are necessarily distinct necessarily distinct from one another.from one another.

P3.P3. I can clearly and distinctly conceive I can clearly and distinctly conceive my mind apart my mind apart from my body.from my body.

P4.P4. Therefore, my mind can exist apart Therefore, my mind can exist apart from my body.from my body.

----------------------------------------------------------------------------------------------------------------------------------C.C. Therefore, my mind is necessarily Therefore, my mind is necessarily

distinct from my distinct from my body.body.

Real Distinction ArgumentReal Distinction Argument

P1.P1. Whatever can be clearly and distinctly Whatever can be clearly and distinctly conceived conceived apart can exist apart.apart can exist apart.

P2.P2. Whatever can exist apart are necessarily Whatever can exist apart are necessarily distinct distinct from one another.from one another.

P3.P3. I can clearly and distinctly conceive my I can clearly and distinctly conceive my mind apart mind apart from my body.from my body.

P4.P4. Therefore, my mind can exist apart from my Therefore, my mind can exist apart from my body.body.

----------------------------------------------------------------------------------------------------------------------------------C.C. Therefore, my mind is necessarily distinct Therefore, my mind is necessarily distinct

from my from my body.body.

A way of talking about the A way of talking about the possibilitypossibility of separation even of separation even where there is no such actual separation.where there is no such actual separation.

Real Distinction ArgumentReal Distinction Argument

P1.P1. Whatever can be clearly and distinctly Whatever can be clearly and distinctly conceived conceived apart can exist apart.apart can exist apart.

P2.P2. Whatever can exist apart are necessarily Whatever can exist apart are necessarily distinct distinct from one another.from one another.

P3.P3. I can clearly and distinctly conceive my mind I can clearly and distinctly conceive my mind apart apart from my body.from my body.

P4.P4. Therefore, my mind can exist apart from my Therefore, my mind can exist apart from my body.body.

----------------------------------------------------------------------------------------------------------------------------------C.C. Therefore, my mind is necessarily distinct Therefore, my mind is necessarily distinct

from my from my body.body.

A consequence of the necessity of the non-separability of A consequence of the necessity of the non-separability of identical things.identical things.

Real Distinction ArgumentReal Distinction Argument

P1.P1. Whatever can be clearly and distinctly Whatever can be clearly and distinctly conceived conceived apart can exist apart.apart can exist apart.

P2.P2. Whatever can exist apart are necessarily Whatever can exist apart are necessarily distinct distinct from one another.from one another.

P3.P3. I can clearly and distinctly conceive my I can clearly and distinctly conceive my mind apart mind apart from my body.from my body.

P4.P4. Therefore, my mind can exist apart from Therefore, my mind can exist apart from my body.my body.

----------------------------------------------------------------------------------------------------------------------------------C.C. Therefore, my mind is necessarily distinct Therefore, my mind is necessarily distinct

from my from my body.body.

A conclusion that Descartes reached in A conclusion that Descartes reached in Meditations 1, Meditations 1, 22..

Real Distinction ArgumentReal Distinction Argument((Deriving the 3Deriving the 3rdrd Premiss) Premiss)

He can’t be certain that bodies exist because the evidence He can’t be certain that bodies exist because the evidence for them is merely sensory, and the senses can be deceived. for them is merely sensory, and the senses can be deceived.

The same possibility of error does not exist for the claim The same possibility of error does not exist for the claim that his mind exists. (‘that his mind exists. (‘Cogito ergo sumCogito ergo sum’.) ’.)

So he exists as a thinking thing. But are mind and body So he exists as a thinking thing. But are mind and body distinct? Consider their essences. distinct? Consider their essences. The example of wax: the essence of the wax is extension The example of wax: the essence of the wax is extension

(occupying space) and is known not through the senses (occupying space) and is known not through the senses but through ‘a purely mental contemplation’ but through ‘a purely mental contemplation’

the essence of Mind is thinking.the essence of Mind is thinking. The fact that the idea of thinking does not entail the idea of The fact that the idea of thinking does not entail the idea of

extension or vice versa shows that the one cannot be a extension or vice versa shows that the one cannot be a mode of the other. mode of the other.

Real Distinction ArgumentReal Distinction ArgumentObjectionsObjections

1.1. He has not shown that he has a clear and He has not shown that he has a clear and distinct idea of the mind apart from the body. distinct idea of the mind apart from the body.

He assumes that unless the concept of body is He assumes that unless the concept of body is a part of the definition of ‘mind’ a complete a part of the definition of ‘mind’ a complete concept of the mind is possible apart from that concept of the mind is possible apart from that of the body of the body

BUTBUT

there might be necessary external relations there might be necessary external relations between things that rules out having a between things that rules out having a complete concept of the one without the other. complete concept of the one without the other. Eg. correlative terms like ‘parent’ and ‘child’ Eg. correlative terms like ‘parent’ and ‘child’

Real Distinction ArgumentReal Distinction ArgumentObjectionsObjections

2.2. Excluding Body from my essence is just an Excluding Body from my essence is just an intellectual abstraction intellectual abstraction

Compare thinking of something as being a Compare thinking of something as being a right angled triangle but doubting whether right angled triangle but doubting whether the square of its hypotenuse was the sum of the square of its hypotenuse was the sum of the squares of the other two sides. the squares of the other two sides.

Real Distinction ArgumentReal Distinction ArgumentObjectionsObjections

3.3. The argument is a fallacy. The argument is a fallacy.

p1.p1. I can conceive of my mind as unextended.I can conceive of my mind as unextended.p2.p2. I can not conceive of my body as unextended.I can not conceive of my body as unextended. --------------------------------------------------------------------------------------------------------------c.c. Therefore my body and my mind are distinct.Therefore my body and my mind are distinct.

BUTBUTp1.p1. I can conceive of the evening star as being different I can conceive of the evening star as being different

from Venus.from Venus.p2.p2. I can not conceive of Venus as being different from I can not conceive of Venus as being different from

Venus. Venus. ----------------------------------------------------------------------------------------------------------------------------------------------

c.c. Therefore the evening star and Venus are distinct.Therefore the evening star and Venus are distinct.

The Argument from DivisibilityThe Argument from Divisibility

P1.P1. The mind is indivisible.The mind is indivisible.P2.P2. The body is divisible.The body is divisible.P3.P3. If A is identical with B, then any property that If A is identical with B, then any property that

A has B also has.A has B also has.

------------------------------------------------------------------------------------------------------------------------------------------------------------

C. C. Therefore, the mind is distinct from the body.Therefore, the mind is distinct from the body.

The Argument from DivisibilityThe Argument from DivisibilityObjectionsObjections

1.1. It makes very good sense to talk about the It makes very good sense to talk about the parts of a mind or even of divided minds. parts of a mind or even of divided minds.

2.2. Certain cognitive functions depend upon the Certain cognitive functions depend upon the body, such as perception, memory. body, such as perception, memory.

3.3. Descartes equivocates upon the word ‘division’ Descartes equivocates upon the word ‘division’

Mind/Body DualismMind/Body Dualism

Popular DualismPopular Dualism

The Mind drives the body like a man in a tank.The Mind drives the body like a man in a tank.

Mind/Body DualismMind/Body Dualism

Substance DualismSubstance Dualism

The world consists of at least two types of The world consists of at least two types of thing, two thing, two substancessubstances, one of which is , one of which is material and is essentially extended, and the material and is essentially extended, and the other of which is mental and is essentially other of which is mental and is essentially thinking thinking ..

Mind/Body DualismMind/Body DualismObservationsObservations

Mind does not give life to the body Mind does not give life to the body

The soul does not dwell in the body like a pilot in The soul does not dwell in the body like a pilot in a shipa ship

Descartes says that the soul is ‘substantially united’ to the Descartes says that the soul is ‘substantially united’ to the body, or body, or ‘mixed up in ‘mixed up in iit’.t’.

a subtle fluid – the a subtle fluid – the animal spiritanimal spirit – flows through – flows through the nerves and is the medium of communication the nerves and is the medium of communication between mind and body. between mind and body.

MindMind Pineal glandPineal gland Nerve fibres Limbs Nerve fibres Limbs Sense organs Sense organs Nerve fibresNerve fibres Pineal glandPineal gland MindMind

Mind/Body DualismMind/Body DualismObjectionsObjections

1.1. The most common objection to substance dualism The most common objection to substance dualism is that it is inconceivable that the two substances is that it is inconceivable that the two substances should be able to affect each other at all. should be able to affect each other at all.

ResponsesResponses

a.a. OccasionalismOccasionalism. .

b.b. Pre-established Harmony.Pre-established Harmony.

c.c. Double-AspectDouble-Aspect..

Princess Elizabeth to Princess Elizabeth to Descartes: Descartes:

I admit it would be easier I admit it would be easier for me to concede matter for me to concede matter and extension to the soul and extension to the soul than the capacity of than the capacity of moving a body and of moving a body and of being moved, to an being moved, to an immaterial being.immaterial being.

Descartes to Princess Descartes to Princess Elizabeth:  Elizabeth:  

I beg [Your Highness] to I beg [Your Highness] to feel free to attribute this feel free to attribute this matter and matter and extension to extension to the soul because that the soul because that is is simply to conceive of it as simply to conceive of it as united to the body.united to the body.

Mind/Body DualismMind/Body DualismObjectionsObjections

1.1. The most common objection to substance dualism The most common objection to substance dualism is that it is inconceivable that the two substances is that it is inconceivable that the two substances should be able to affect each other at all. should be able to affect each other at all.

2.2. There are objections to Dualism on the grounds of There are objections to Dualism on the grounds of various conservation laws. various conservation laws.

3.3. Ockam’s Razor. There is no increase in Ockam’s Razor. There is no increase in explanatory power provided by this new explanatory power provided by this new substance. substance.

4.4. Scientific Psychology speaks against dualism. Scientific Psychology speaks against dualism.