Transcript Smith’s Invisible Hand

Philosophy of Mind Mind/Body
Introduction to Philosophy
Jason M. Chang
Lecture outline
1.
Mind/body dualism
2.
Materialism views
•
•
Behaviorism
Mind-brain identity theory
Mind/body dualism
•
Rene Descartes (1596-1650)
About this view
o
Dominant historical view
o
Common sense view today
o
Among academics?
Mind/body dualism
Claim #1: Human consists of two substances
PHYSICAL
SUBSTANCE (BODY)
NONPHYSICAL
SUBSTANCE (MIND)
Mind/body dualism
Claim #2: Mind and body interact with each other
PHYSICAL
SUBSTANCE (BODY)
NONPHYSICAL
SUBSTANCE (MIND)
Note: The type of mind/body dualism discussed here is interactive mind/body dualism.
Mind/body dualism
Claim #3: Mental states are nonphysical states
Thoughts
Emotions
Sensations
-Intangible
-Cannot be observed
-No space or weight
Mind/body dualism
Descartes’ conceivability argument
Try to imagine a world in which:
(1) The number 4 exists
(2) The sum of 2+2 does not exist
Can you do so?
Impossible to imagine two identical things existing apart from each other
Mind/body dualism
Descartes’ conceivability argument
Imagine that you wake up one
morning. You go to the bathroom
and you look in the mirror. To
your astonishment, you see
nothing. You each up to feel your
head, but you cannot feel
anything.
Mind/body dualism
Descartes’ conceivability argument
(P1) We can imagine the mind existing without the
body.
(P2) We can imagine the body existing without the
mind.
(P3) If we can imagine two things existing without
each other, they are not the same thing.
Therefore,
(C) The mind and the body are two separate
things.
Mind/body dualism
Descartes’ different features argument
List the properties of:
(1) The house of the U.S. president
(2) The house on 1600 Pennsylvania
Avenue
Two identical things must have the same features
Mind/body dualism
THE BODY
-Publicly observable
THE MIND
-Not publicly observable
Mind/body dualism
Descartes’ different features argument
(P1) The body has the feature of public.
(P2) The mind has the feature of private.
(P3) Things with different properties cannot be
the same
Therefore,
(C) The mind and the body are two separate
things.
Mind/body dualism
The mind/body problem
In the film Ghost, Patrick Swayze’s character is
killed early in the film. His “spirit”, however,
survives and roams around NY city.
Swayze’s character tries to get in contact with
his wife (Demi Moore) – if not by touching
her, then writing note on a paper or moving an
object in their apartment.
However, Swayze’s character encounters a
difficulty when trying to in contact with her.
Film: Ghost (1990)
What is this difficulty?
Mind/body dualism
The mind/body problem
•
Film: Ghost (1990)
Major ideas
o
Beliefs about causation
o
Mind/body dualism’s
claims
Mind/body dualism
The mind/body problem
The problem of explaining how an
nonphysical substance (the mind)
affects a physical substance (the
body)
Alternatives to
mind/body dualism
Problem – explaining how
these interact
Nonphysical
substance
Physical
substance
MATERIALISM
(PHYSICALISM)
Behaviorism
•
Background
•
Major proponents
o
o
o
John Watson
BF Skinner
Gilbert Ryle
Gilbert Ryle 1900-1976
Note: The type of behaviorism discussed in this lecture is logical (aka analytical) behaviorism.
Behaviorism
Claim #1: “Mental states” are simply behaviors
Dualism’s account of anger
ANGER =
internal
mental state
Behaviorism’s account of anger
ANGER =
external
behavior
Behaviorism
Jane the yard duty
Imagine Jane has yard duty at a
preschool. She is surrounded by noisy
children and one of them squirts water
in her ear. As a result, Jane shouts.
What does it mean to say Jane is
“angry”?
Jane the yard duty shouts
Behaviorism
Dualism
Kids
screaming
Internal
mental state
of anger
Behaviorism
Kids
screaming
Impose label “anger”
Behaviorism
Claim #2: Causes of behavior are external stimuli
Dualism’s account of behavior
Behaviorism’s account of behavior
External
stimuli
Internal
mental state
of anger
Jane shouts
Jane shouts
Behaviorism
A dog salivates when presented
food. But suppose that you
present the food with a ringing
bell. And you do this
repeatedly.
Now, take away the food and
only ring the bell. What
happens?
What is the cause of the dog salivating?
Behaviorism
Biological
make-up
External
factors
Past
experiences
Trigger
(bell ringing)
Biological
make-up
External
factors
Past
experiences
Trigger
(Screaming kids)
The dog’s behavior
can be explained
purely in terms of
external factors
NO NEED FOR
INTERNAL
MENTAL STATES
A human’s behavior
can be explained
purely in terms of
external factors
NO NEED FOR
INTERNAL
MENTAL STATES
Behaviorism
ANGRY
Objection
•
Behaviorism says mental states are
behaviors
•
BUT some mental states do not
translate into behaviors
•
So mental states must exist
independent of behaviors
Mind-brain identity theory
•
Type of theory
o
•
Materialism (physicalism
20th century theory (1960s)
o
Coincides with rise in brain
imaging (fMRI, EEG, etc)
Mind-brain identity theory
Claim #1: Mental states exist
independent of behavior
•
How different from
behaviorism
•
How different from dualism
Mind-brain identity theory
Claim #2: Mental states are brain states
Computer game = functioning hardware
Mind-brain identity theory
Mental state (anger) = physical state of brain
Mind-brain identity theory
Reasons in favor of mind-brain identity theory
•
Images from brain imaging (fMRI, EEG, etc)
•
Stories of traumatic damage to the brain
•
Surgery under local anesthesia
•
Mind-altering drugs
Mind-brain identity theory
Objection – the problem of subjectivity
•
Main ideas behind objection
o
Mental states = physical states
o
Complete explanation
o
Complete explanation not possible
Mind-brain identity theory
Objection – the problem of subjectivity
Imagine that I can give you a complete,
perfect, and precise description of the physical
state of the brain of someone who is in love.
Call this brain state B(Love).
Have I given a complete description of the
of mental state of “being in love”?
Mind-brain identity theory
Physical state of
the brain in love
Mental state of
being in love
There is something that it is like to being in love
A complete explanation of the brain state leaves out the
subjective element of the mental state
Mind-brain identity theory
Objection – the problem of subjectivity
(P1) If mental states are identical to physical states, I should be able to give
a complete explanation of a mental state in terms of its corresponding
physical state.
(P2) It is impossible to give a complete explanation of a mental state that
refers only to physical states.
Therefore,
(C) Mental states and physical states are not identical.