From: tobis@meteor.wisc.edu (Michael Tobis)
Newsgroups: comp.ai.philosophy
Subject: Re: Brain and Mind (was: Logic and God)
Date: 14 Oct 92 22:55:58 GMT
Article-I.D.: meteor.1992Oct14.225558.29323
Organization: University of Wisconsin, Meteorology and Space Science

In article <1250@tdat.teradata.COM> swf@tdat.teradata.com (Stanley Friesen) writes:
>In article <1992Oct9.040228.2117@meteor.wisc.edu> tobis@meteor.wisc.edu (Michael Tobis) writes:
>|In article <1992Oct8.230422.5045@hilbert.cyprs.rain.com> max@hilbert.cyprs.rain.com (Max Webb) writes:

>|It has become clear to me that, as Searle points out in his Scientific
>|American article, that this "systems" argument is a dualist position,
>|so it can't be advanced in the cause of materialism! (an odd mirror of
>|what you accused me of, but to me it seems a valid point.)

>Bah!  Then claiming that life is an emergent property of certain chemical
>processes is a form of animism!

So what? I did not claim that Searle's argument was an argument against
animism, but people have claimed that the systems reply was a defense of 
materialism, which it is not. It may be consistent with some sort of monism,
but certainly not a materialistic one, and hence I would venture, not
plausibly emergent from purely physical principles.

>Emergence is merely the claim that for analysis to procede an additional
>elevel of abstraction is necessary.  Microlevel analysis of neural
>function does not reveal consciousness, it is the higher level *interactions*
>of the nueral operations that do reveal it.  (No more than life is found
>by studying the reaction of individual enzymes in a test tube).

Well, it seems to me that breathing is an emergent property of the physical
world: we can define cells from structures of biochemical stuff, organs
from cells, and functions of the organs from energy exchanges or oxygen
fluxes thorugh boundaries that can objectively be defined. But mind
is different from breathing in that we have no way of defining mind in
terms of the physical properties of the brain. Like trying to extract 
diatonic music from the axioms of ZF, the categories are incommensurable.

Thus we have no way of knowing whether
mind exists outside ourselves, save by analogy to ourselves and intuitive
judgement. This used to be just a cute philosophical quandary, but now that
Turing-test passing algorithms are seriously in prospect, and now
that people are proposing that Turing-test algorithms should have rights
it is a serious practical question.

>|>Nevertheless, one response to your request goes: We are continuous with
>|>the rest of the animal kingdom. You, for example claim cats are alive.
>|>Simpler members of the animal kingdom have had their entire nervous systems
>|>mapped out, and simulated, with _IDENTICAL_ behavior resulting.

>|Furthermore, we are continuous with all of matter, but there is a mysterious
>|discontinuity somewhere between ourselves and a virus, one side of which
>|has an experience and the other side which doesn't. This phenomenon remains
>|untouched by science, except as an observation that it does exist.

>As a trained biologist (one of the few in this news group), I see *no*
>such discontinuity.  Quite the contrary, I find no place where I can
>identify any sharp break along the continuum from non-life to human life.

There is no objective break, but it certainly seems likely that there is
an unverifiable break between things that have an experience and things 
that don't. It seems to me that mind is a quantum phenomenon in the older
sense of the word: there must be an integer number of minds in the universe.
There is no meaning to concepts of half-mind or proto-mind. Hence, there
must be a discontinuity among living species (assuming that a virus has
no experience.) However, where this discontinuity is will remain unkown
until the oft threatened but as yet unrealized theory of the "emergence"
of consciousness arises.

>It sounds like there is nothing you would accept as evidence of consciousness.
>If so, I doubt you will ever accept anything other than humans as conscious.

Yes, I believe that the only test possible is the so-called Turing Test, i.e.,
just plain guessing. I think to design a purely algorithmic Turing Test
passer is precisely to design a system that will make us guess that
somebody's home when nobody is. I do not know whether this is possible.
I suspect it is possible but fervently hope that it is not.

However, I accept mammals and birds as conscious in the metaphysically
interesting sense, that is to say, I believe they have an experience.
This is just a guess, though. Fortunately, no one is offering voting
rights to chickens just yet, so it is not an important policy question.

>This could be a problem for you when the Galactic Federaion finally gets
>around to sending its ambassador to Earth! (:-))

Granted.

>Really, the issue at hand is how to recognize non-human consciousness.
>It is no different in principle in the case of space aliens than it is with
>computers.

Agreed.

>In neither case do we have access to thier subjective experience, so we must
>rely on external data to determine its presence.

>So, what *evidence* would you require to accept a being from another planet
>was conscious?  How would you distinguish a 'real' aliem from a perfect
>'android' type robot?  

I dunno. Beats the hell out of me. Hopefully they would not try to immigrate
to our turf and we could avoid the issue.

>(For that matter, is the distinction even meaningful)?

Yes, yes, a googol times yes! It is the most important distinction around!

Unfortunately, it is meaningful only outside pure science because the
existence of subjective experience is not objectively verifiable. That is why
(I guess) some people whose faith in the scientific method goes beyond the
robustness of its conclusions (with which I fully agree) to the completeness
of its possible conclusions (which I doubt) are willing to make the bizarre
assertion that consciousness is some sort of illusion. Just who or what is
being deceived???

mt
Newsgroups: comp.ai.philosophy