From newshub.ccs.yorku.ca!torn!cs.utexas.edu!uwm.edu!daffy!uwvax!meteor!tobis Mon Nov  9 09:36:43 EST 1992
Article 7509 of comp.ai.philosophy:
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>From: tobis@meteor.wisc.edu (Michael Tobis)
Subject: Re: Your victory is your defeat
Message-ID: <1992Nov4.231123.26065@meteor.wisc.edu>
Organization: University of Wisconsin, Meteorology and Space Science
References: <1992Oct28.221356.9095@meteor.wisc.edu> <1992Oct31.013730.27375@hilbert.cyprs.rain.com>
Date: Wed, 4 Nov 92 23:11:23 GMT
Lines: 89

In article <1992Oct31.013730.27375@hilbert.cyprs.rain.com> max@hilbert.cyprs.rain.com (Max Webb) writes:
>In article <1992Oct28.221356.9095@meteor.wisc.edu> tobis@meteor.wisc.edu (Michael Tobis) writes:
>
>[A whole bunch of quotes on the difference between subjective and objective,
>constituting an appeal to authority...].

The appeal was admittedly not to logic, but that doesn't make it an appeal
to authority. It was an appeal to experience, or to subjective evidence.
>1) A physiologist grows up in an immunoprotective plastic bubble.
>Only blue light shines in this bubble, and she never sees red in her
>life.

It seems to me that ordinary mundane color blindness would do, but no
matter...

>2) However, this physiologist has studied color perception, and
>knows _EVERYTHING_ about the physical process (including neurology,
>optics, the whole shebang) of color perception.
>
>3) She doesn't know what red is like (when viewing it). Therefore,
>red perception cannot be entirely a physical process.
>
>Is this as representative of your line of argument, as I think it is?
>
>The fallacy in the above argument is that the verb 'know' is used
>in one sense in (2) (theoretical understanding), in another sense in
>(3) (sensory familiarity); the two definitions are conflated, resulting
>in a fallacy of equivation.

Fascinating! I would claim that the word "perception" has been used in
two senses. In 2) the word refers to the information processing aspects
while in 3) it refers to the experiential (and thus philosophically 
interesting) aspects. It reduces to the same thing of course. 

I leave aside the question as to whether knowing "everything" about
the physiology of color perception is well-defined or meaningful, 
since really neither of us is happy with the argument.

Nevertheless, the main point I am making is in there somewhere, which is
that there are two distinct phenomena happening: 1) the information about
the spectral content of a light source has been processed by an information
processing entity which may use the information in some way, and 2) the
experience of red has happenned. Explanations of 1) do not constitute 
explanations of 2), and no amount of handwaving in the direction of 2)
has as yet shed any light on the phenomenon of the sort that has been
so spectacularly successful on phenomenon 1).

>Whether or not that argument was a good summary, the following is true:
>
>No amount of knowledge about an experience, provides
>you with that experience. But why should we expect it to?

Oh, you think I argue that because there is no "redness" to the experience
of understanding the physiology of color perception that physiology
sheds no light on color perception. I argue no such thing.

I argue that there is a subjective "redness" to the experience of red
perception, and a subjective "knowing" to the experience of learning
physiology. The vast and detailed information about the information 
processing aspects and physical correlates of these processes, however
impressive, offers nothing toward explaining or objectively detecting
the experiences themselves.

This is my biggest problem (among several) with the program of AI.
Of course it is possible to design a system which will report "I see
red" when a red object is present, and of course we will tell one another
"it sees something red". But we should not allow ourselves to confuse
ourselves into thinking that we know whether or not the experience of
redness is occurring. We do not know and cannot know. 

>Your invocation of immaterial boojums hasn't bridged the barrier

It wasn't me that mentioned boojums, just someone being snarky. 
I do maintain that there is a phenomenon which cannot be described
using physical processes. Call it a boojum if you will. It spares me
some unfortunate allies by avoiding the traditional vernacular name
for the phenomenon, which has all sorts of superstitious connotations.

>between objective and subjective - it has just pushed the question
>up where you are less likely to ask it. Not progress, as far as I
>can see.

Au contraire, its explicit intention is to highlight the question.
For me, "progress" would be to admit that no progress has been made, and we
don't know where to begin. Why are you so certain the barrier can be bridged?

mt




