Transcript The Mind – Body Problem - University of Mississippi

LAST LECTURE
Functionalism
Functionalism in philosophy of mind is the view
that mental states should be identified with and
differentiated in terms of functional roles.
A function (as in mathematics) relates inputs to
outputs. (e.g. multiplication vs. addition)
A functional role would determine a specific kind
of function.
Functional Concepts (1)
Part of FUNCTIONALISM is conceptual.
In a ‘stuff’ concept, what a thing is and what it
does is a matter of the nature of the stuff. To
be water is to be liquid and wet. To be wood
is to be…, to be a sheep is to be… .
Most ‘STUFF’ concepts are the concepts of
certain kinds in nature (or ‘natural kinds’).
Functional Concepts (2)
A functional concept identifies what a thing IS
with what it does.
To be a knife, is to be a thing that cuts
To be money, is to be the kind of thing that
permits economic exchange
To be an umpire, is to be the person who
adjudicates events in a baseball game.
To be a chess queen, is to be a piece that
moves and captures in a specified manner.
Functional Concepts (3)
If we say that a mental state is a functional kind,
then we say that to be “in pain” is to be in
that state that relates injury to behaviors of
type T.
What the mental states have in common is the
functional profile of relating input to output. If
two functional states relate the same inputs to
the same outputs then they are the same
function.
Examples…
Two word processing programs will have different
computer code, but will perform the same work.
Same function different realization.
A Calculator and an abacus will both perform simple
mathematical calculations, but one is digital and one
is analog.
A digital clock and a wind-up cuckoo clock both keep
time, etc.
Same function different form…
Function and Multiple Realization
One of the primary reasons people entertain
functionalism about mental states is that
functional states are multiply realizable.
Recall: MR was a problem for identity theory.
Now it is a virtue of Functionalism.
Functionalism Review
1) Functionalism in philosophy of mind is the view that
mental states should be identified with and
differentiated in terms of functional roles.
2) A function (as in mathematics) relates inputs to
outputs. (e.g. multiplication vs. addition). A functional
role would determine a specific kind of function.
3) Functional Concepts define things relative to functions
4) Functions are multiply realizable.
According to Functionalism…
To be in a mental state S is to have your brain realize a
functional state F.
Not observable
Observable
Two models
Behavioral Model
Stimuli
Mind Plays a role(?) model
WHY ISN’T
FUNCTIONALISM
JUST A VERSION
OF
BEHAVIORISM
Conditioned
Responses
Stimuli
MENTAL
EVENTS
Determines
Type
Behavior
Behavior
Not observable
Observable
More Models
Functional Model
Mind Plays a role(?) model
Stimuli
Functional
State
Behavior
Stimuli
…Because the
functional role
determines what the
state is, not the
input/output pair
…that means, e.g.,
pain and fake-pain
are different
states…
MENTAL
EVENTS
Behavior
Hardware – Software Analogy
According to one version of Functionalism
The brain is like a computer and your mental
states are like programs that run on that
computer. The same computer can run
different programs at different times and the
same (or similar) programs can be run on
different computers.
Objection to Functionalism
Block’s Liberalism Objection:
If having a functional organization F is sufficient
for being in mental state M, then anything
which realizes F will be M.
So if F1 is “being in love with Laura Bush”, and
a crashing wave contains water molecules
that realize F1, then the wave loves Laura
Bush.
See the unhappy rainbow?
The Qualia Objection
 Similar to the Conscious experience argument for dualism.
1) Conscious experience contains more information than the
physical facts provide: ‘What its like to X’ or Qualia
2) Qualia has no functional role.
3) If functionalism is true there is no requirement that functional
states have associated qualia. Thus mental states need not
have qualia. (Qualia Zombies)
4) But the presence of qualia is paradigmatic of consciousness.
And consciousness is a mental state.
----------------------------------------------------------------5) Therefore, functionalism is not a complete account of mental
states.
Functionalism and Artificial
Intelligence (AI)
Non-Biological Realization:
If a functional state can be realized outside of a
biological system, then can we build a system
(e.g. in a computer) that has REAL mental
states?
Such a system would be a form of Artificial
Intelligence. (AI)
Types of AI
There are two conceptions of AI
Strong AI – non-biological systems can realize
real mental states.
Weak AI – non-biological systems can only
simulate mental states. We can learn about
the mind by studying these systems, but they
are not real minds.
Is Simulation just Simulation?
 Simulated Weather
 Simulated Sunlight
 Simulated Flight
 Simulated Clocks
What kind of simulation is an AI system?
Can Machines (really) Think: The
Turing Test
In a famous 1950 paper PhilosopherMathematician Alan Turing asked:
“Can a machine think?”
To answer the question he proposed an
experiement called the ‘Imitation Game’ or
(later) Turing Test
Turing and Turing Machines
ALAN M. TURING
He developed a way to resolve complex
mathematical problems using imaginary machines
(digital computers)
One kind of Turing Machine:
A Turing “Bombe” code-breaker
A Basic Turing Machine Diagram
INPUT
OUTPUT
PROCESSOR
One way to make a TM is
to write a program that
wins the Turing Test
MEMORY
Turing Machines are MR
A Turing machine can be
diagrammed …or built of
metal
…or of blueberry muffins
and frosting.
…AND STILL BE A Turing
Machine
The Imitation Game…
A Man in a chat-room
pretends to be a woman
A woman in a chat-room
answers questions as she
normally would
You may ask any question you want for 15 minutes via
computer. If you cannot tell who the real woman is, then the
man wins. He is indistinguishable from the woman.
The Turing Test: A computer tries to
imitate a human…
COMPUTER
WHICH IS WHICH? IF YOU CAN’T TELL, IS THERE A
DIFFERENCE?
Try the Turing Test on your friends…
How do you know that they can think?
Imagine that you could only talk to them in a
chat room or in some other setting where
behavior was not a factor.
You would ask questions and judge on the
basis of answers.
Objections to Turing’s Claim
Turing doesn’t answer his own question. He gives a
test, and suggests that computers will be able to pass
it at some point
Here are some traditional objections:
1) The Soul: you must have a soul to think.
2) Originality: Computers must obey programs so they
cannot do anything original.
3) Humor: Thinking yields humor, machines don’t make
jokes.
4) Head in the Sand: Oh dear, wouldn’t be awful if they
did think?
5) Learning: Machines can’t learn, but thinkers can.
Turing’s Replies…
1) The Soul: you must have a soul to think.
-- God could make a thinking machine…
2) Originality: Computers must obey programs so they
cannot do anything original.
-- Programs could incorporate randomness
3) Humor: Thinking yields humor, machines don’t make
jokes.
-- Why must thinking and humor coincide?
4) Head in the Sand: Oh dear, wouldn’t be awful if they did
think?
-- A worry is not an objection.
5) Learning: Machines can’t learn, but thinkers can.
-- Complex machines can acquire new inputs from the
environment and previous processing.
Searle’s Chinese Room
The best known objection to strong AI is John
Searle’s CHINESE ROOM objection.
The objection is this:
If a system can pass the
Turing Test then it
understands language, but
in a Chinese Room there is
no part that understands
language. So at best a TT
simulates thinking.
The Chinese Room
MEMORY
OUTPUT
INPUT
PROCESSOR