The Mind-Body Problem

 

I.  Cartesian Arguments for Dualism

          A.  Argument from Conceivability

 

P1:            I can conceive of me existing without my body.

C1:            So it is possible that I exist but my body doesn’t.

P2:            If a = b, then necessarily a = b.

C2:            So I am not identical to my body.

 

          B.  Argument from Essences

 

P1:            I am (only) essentially a thinking thing.

P2:            My body is (only) essentially an extended thing.         

P3:            If a = b, then they have the same essence.    

C:            I am not identical to my body.

 

          C.  Argument from Doubt

 

P1:           I can doubt that my body exists.

P2:           I cannot doubt that I exist.

C1:            So my body has a property that I do not have.

P4:            Leibniz’s Law: If a = b, then a and b have all the same properties.

C2:            So I am not identical to my body.

 

          D.  Refutation by Logical Analogy

 

P1:           Lois can doubt that Superman is Clark Kent.

P2:            Lois cannot doubt that Clark Kent is Clark Kent.

C1:            So Superman has a property that Clark Kent does not have.

P4:            Leibniz’s Law: If a = b, then a and b have all the same properties.

C2:            So Superman is not identical to Clark Kent.

 

II.  Problem of Mental Causation

P1:    If dualism is correct, then mind and body are radically different substances.

 

P2:            Radically different substances cannot causally interact.

2a:            Causal interaction requires something like contact in a common medium.

 

2b:            Radically different substances cannot come into contact with one another in a common medium.

 

P3:            Mind and body do causally interact.

3a:            Perception: Physical states (opening eyes in a well-lit room) cause mental states (visual sensations).

3b:            Intentional Action: Mental states (beliefs and desires) cause physical states (bodily movements).

 

C:            So dualism is not correct.

 

 

III. Problem of Consciousness

P1:    There is something it is like to be in certain conscious mental states (e.g., having a visual sensation of red)—certain mental states have a qualitative feel.

 

P2:    What it is like to be in certain mental states is not determined by the totality of relevant physical facts.

 

C:      So the qualitative feel of mental states is not a physical property.