Dualism
THE PRINCESS ELIZABETH ARGUMENT
Cartesian Dualism
 Substance Dualism: Mental states are non-physical states
of an immaterial mind. Pain is a non-physical state of the
immaterial mind.
 Interactionism: The brain and the mind of a typical
person enter into two-way causal interaction (i.e., bodily
events cause mental events and vice versa).
The Parody Argument
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7.
I can conceive of Superman (SM) existing without Clark
Kent (CK).
If (1), it’s possible for SM to exist without CK.
If it’s possible for SM to exist without CK, SM can exist
without my CK.
[So] SM can exist without CK.
CK cannot exist without CK.
If (4) and (5), SM is not identical to CK.
[So] SM is not identical to CK.
The Conceivability Argument
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7.
I can conceive of me existing without my body.
If (1), it’s possible for me to exist without my body.
If it’s possible for me to exist without my body, I can
exist without my body.
[So] I can exist without my body.
My body cannot exist without my body.
If (4) and (5), I am not identical to my body.
[So] I am not identical to my body.
Cartesian Dualism
 Substance Dualism: Mental states are non-physical states
of an immaterial mind. Pain is a non-physical state of the
immaterial mind.
 Interactionism: The brain and the mind of a typical
person enter into two-way causal interaction (i.e., bodily
events cause mental events and vice versa).
The Princess Elizabeth Argument
I [question] how the mind of a human being, being only a
thinking substance, can determine the bodily spirits in
producing bodily actions. For it appears that all
determination of movement is produced by the pushing
of the thing being moved, by the manner in which it is
pushed by that which moves it, or else by the
qualification and figure of the surface of the latter.
Contact is required for the first two conditions, and
extension for the third. [But] you entirely exclude the
latter from the notion you have of… an immaterial
thing.
The Princess Elizabeth Argument
 Newton’s First Law of Motion: The motion of an object
will remain unchanged unless some force acts upon it.
 Newton’s Second Law of Motion: Force equals mass
times acceleration.
The Princess Elizabeth Argument
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2.
3.
4.
5.
If Cartesian Dualism is correct, immaterial minds affect
the motion of material objects.
If immaterial minds affect the motion of material
objects, they exert force.
If immaterial minds exert force, they have both mass
and spatial location.
Immaterial minds don’t have mass or spatial location.
[So] Cartesian Dualism is incorrect.
The Princess Elizabeth Argument
 An event e is causally overdetermined iff there are two
distinct and causally unrelated events which are both
causes of e.
 Event e counterfactually depends on c iff e wouldn’t have
occurred if c hadn’t occurred.