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Article 1935 of comp.ai.philosophy:
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>From: orourke@unix1.cs.umass.edu (Joseph O'Rourke)
Newsgroups: comp.ai.philosophy
Subject: Re: Searle, again
Message-ID: <40333@dime.cs.umass.edu>
Date: 7 Dec 91 17:39:18 GMT
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Jeff Dalton writes:
>                                                Searle points
>out that the outputs of the sensors, the control instructions
>for the manipulators, etc, are just more symbols that have to
>-- somehow -- be given meanings.  So it's symbol manipulation
>again.

I think it is perhaps misleading to speak only of control "instructions."
Eventually the control instructions are translated into control
voltages.  It seems to me that depositing a "move arm" instruction
into a register that is hardwired to a device that drives the arm
motor with a voltage, exhibits just as much a causal link between
the instruction and the arm movement, as does a mental intention
causing the appropriate neuronal firings that retract a human arm
muscle.  The "move arm" instructions/symbols are given meaning by
the design of the hardware, which seems to me analogous to the
way the firing of certain neurons is "given meaning" by their
connections to arm muscles.
	I fail to see Searle's claim that symbols have no causal
power.  One does not have to use robots:  the same point could
be made about a disk controller.  Deposit the appropriate "symbols"
(which are, afterall, voltages) into the appropriate registers
controlling the disk, and something happens in the physical world
as a result.  Does this not demonstrate that symbols can have
causal power?


