Functionalism

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Functionalism

• Mind and Body
• Knowledge and Reality Lecture 3

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Recall the dualism vs materialism debate. The
materialist says that science discovers what the
world is like. Water fire thunder now we know.
We now even understand life itself. There has
been amazing progress in understanding the world.
The materialists idea is that, soon, even the
mind will be understood and explained. And the
idea or ideal here is to reduce mind to brain,
for example pain to certain brain states.
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Functionalism says, by contrast, that what we are
made of is not important. Computer model of the
mind. A.I.Hardware/software distinction.
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What it is to be a certain mental states is its
role in a system, not what it is made of. Mental
states are () functional roles. In particular.
A) inputs of effects on the body.B) effects on
other mental states. C) bodily behaviour.
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Artificial intelligence (AI)We dont need to
worry about messy brain science, instead we can
understand the mind by building a robot.The
philosophy/psychology/computer science interface.
The question is not what are we made of? As
Hilary Putnam says, we might be made of Swiss
cheese or soul substance and it wouldnt matter.
Ned Blocks coke machine analogy. One state
leads to another. One can give an abstract
description of the coke machine. The same with
us.
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Two systems can be made of different stuff but be
functionally similar (isomorphic). The kind of
explanation appropriate for such systems is
different just as we can explain why we cant
put a square peg in a round hole without
mentioning molecules Different levels of
explanation are involved. For example . Pain
tends to be caused by damage to the body, it
tends to cause distress, and tends to cause us to
wince. The state playing that role is () pain.
And the same for other mental states.
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It follows that mental states could be
differently constituted.We could be made of
chocolate, water. There can be space aliens with
minds who are made of completely different
stuff/substance? And this means that
psychology is autonomous of physical science.
(Thats a matter of knowledge of mind.)
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Functionalism mental states are defined as
dispositional-causal relations between other
mental states and inputs and outputs. (Contrast
with behaviourism.)
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John SearleObjects tofunctionalism
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Younger version
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• For functionalism, and AI The brain is a
  computer, the mind is a program.
• Someone could write a program to enable a
  computer to simulate understanding Chinese. It
  passes the Turing test.
• Does it understand Chinese?
• His famous Chinese room example. (Choose
  another language if you are Chinese.)
• Imagine lots of Clerks in little offices shifting
  around tiles with Chinese characters on them.

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• Searle says, the room has syntax, not semantics.
• This is supposed to show that Functionalism is no
  good, and it cant account for intentionality,
  the fact that we mean things, intend to refer to
  things in the world.
• But, as you know philosophers always have
  replies.

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• The Holism reply
• The whole room understands Chinese although no
  individual clerk does.
• Searle says that this is question-begging?

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• The Robot reply
• Put the whole room in a robot, and have it move
  around, get content from inputs
• In that case maybe syntax does imply
  semantics.
• Maybe one can combine the holism and robot
  replies?

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• But is that enough to create meaning, that is,
  thoughts with worldly content?
• The input tiles might originate in a part of the
  world. But how does that make the sign on that
  tile a sign for that part of the world? Even if
  it somehow is, due to a regular causal account
  (Jerry Fodor), and these tiles are then processed
  in a complex system, that would not give the room
  a notion of truth, of correspondence with the
  world. But without that there is no
  intentionality.

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• So.. the functionalism and the AI program are
  controversial.
• Perhaps there are other problems with any
  broadly materialist approach. In particular
  from
• raw feelings.. As well see
• ..next time