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From: pmd@cbsck.UUCP (Paul M. Dubuc)
Newsgroups: net.philosophy
Subject: Re: mind vs. brain
Message-ID: <1435@cbsck.UUCP>
Date: Mon, 28-Oct-85 13:56:14 EST
Article-I.D.: cbsck.1435
Posted: Mon Oct 28 13:56:14 1985
Date-Received: Thu, 31-Oct-85 23:41:45 EST
References: <1794@watdcsu.UUCP>
Organization: AT&T Bell Laboratories , Columbus
Lines: 67

There is another useful analogy on the distinction between "mind"
and "brain".  Donald M. MacKay (a British scientist) makes it in his
book _Science and the Quest for Meaning_ (Eerdmans 1982).  He describes
the "bogey of determinism" (in this area) as arising from a confusion
of levels at which the operation of the mind is described.  The analogy
he uses deals with a computer.

When a computer is used to compute our income tax and we ask the operator
how the computer functioned in doing so, she would take certain pains
to show that the calculations were done according to certain laws of
arithmetic and income tax laws based on your income bracket, etc.
Ask and engineer who designed the computer the same question, however
and you might be shown the computer's internal workings and be given
a description of how the computer works according to the laws of
physics operating on the mass of transistors and copper that make up
the "brain" of the computer.  Both descriptions are accurate at their
own levels and the fact that all the calculations of the computer
have some physical/mechanical representation does not take away from
the meaning of those actions implied by the operators description of
the computer's calculations.  To say that it does confuses levels of
description.  It is like saying that the words appearing on your CRT
can be explained by the computer's instructions to light up certain
dots on the screen and that they have no significance beyong that--
they're "nothing but" dots on your screen.

MacKay goes into the problem of "brain" vs. "mind" a little more.  I'll
append the following quote from the book cited above (p. 25):

    Assume for the sake of argument that all that you believe and know
    and feel and think is represented in some sense by the physical
    configuration of your brain.  I have shown elsewhere (for example,
    in _Brains, Machines and Persons_) that even if that configuration
    were fully mechanistic in its workings, no complete specification
    of your brain would exist that you would be bound to accept as
    inevitable, unless the specification were of its past.  [This
    possibility would have no bering on the free will question since
    that is exercised in the present (or "immediate future"). -- PMD]
    In particular, no complete specification of the immediate future of
    your brain could have an unconditional claim on your assent, even if
    your brain were as mechanical as the workings of a clock.

    The reason for this, of course, is that if all your mental processes
    are represented in your brain, then no change can take place in
    any mental state of yours without a change also taking place in
    the physical state of your brain.  And therefore the validity of
    any complete specification of your brain depends on whether or not
    you believe it.  So it doesn't have an unconditional claim to your
    assent.  No matter how clever I might be in preparing the specification,
    it can't be equally correct whether or not you believe it.  If I
    accurately describe the make-up of your brain at the moment you
    read or hear my description, it will be incorrect by the time you've
    accepted its truth, because the simple act of acquiescence will have
    changed your brain's make-up.  Alternatively, if I can allow for 
    the effects of your believing the description, so as to produce one
    that you would be correct to believe, then its correctness will *depend*
    on your believing it--so you would not be mistaken to disbelieve it!

    In that sense, then, the immediate future or your brain is open to *you*,
    undetermined for *you*, and would remain so even if the physical elements
    making up your brain were as determinate as the solar system. ...

The book MacKay refers to does go into  more detail on this and is also
well worth reading.  _Brains, Machines and Persons_ is also published by
Eerdmans (1980).
-- 

Paul Dubuc 	cbsck!pmd