Subject: Re: Thought Experiments

From: [email-masked] (ASP-Disc)
Date: Mon, 13 Feb 1995 09:55:27 -0500

From: Mike the mental experimenter <[email-masked]>

Ben,
 
Your responses to Bryan's thought experiment and the Mary-the-
neurologist thought experiment are pretty ridiculous.
 
First, you seem to accuse Bryan of contradicting his own stipulations,
because in the TE, he first supposes that we have deterministic laws for
predicting your behavior, but then he says that you could still falsify
the prediction.  But this is no flaw in Bryan's reasoning; it's just the
way any reductio ad absurdum argument goes.
 
You say that given the stipulation, it follows that you couldn't falsify
the scientists' prediction but would act as predicted.  That's right. 
That's why it's a reductio ad absurdum.  The assumptions we make entail
that you could not falsify the prediction.  But that's absurd.  Of
course you could.
 
Next, you claim -- and maybe this is really what the first point was
getting at -- that you don't know whether or not you could falsify the
scientists' prediction, because you can't clearly imagine the situation. 
You make a similar claim that you don't know whether Mary the expert
neurophysiologist would recognize a blue bananna because you can't
imagine her situation either.  Similarly, some people respond to
Searle's Chinese Room by saying they don't know whether they would
understand Chinese in the imaginary situation.
 
Come on.  You can tell some things about situations you haven't been in,
and this is not the place to raise skeptical doubts about such
judgements in general.  You know that eating a fortune cookie would not
give you an understanding of Chinese; you know swimming in the Yangtze
River wouldn't give you an understanding of Chinese; and now isn't the
time to question how you can possibly know such things (since you've
never swum in the Yangtze).  And unless you're going to question those
judgements as well, I would see no reason to doubt the equally obvious
sense that manipulating a bunch of Chinese symbols according to a rule
book wouldn't give you an understanding of Chinese.  These sort of
thought experiments just bring out our basic understanding of how
certain things in the world work.
 
Again, you know that a color-blind person can't learn what the sensation
of blue is like by looking at the sky.  You know he can't learn it by
reading a description in a dictionary.  It's equally obvious that he
can't learn it by studying the physiology of the brain.  I don't see
what the big problem with imagining the last situation is supposed to
be.  If you don't think you can imagine it, just read a couple pages
from a brain science text.
 
Moreover, your claimed lack of imaginative powers isn't really relevant. 
I think you know that eating a live squid wouldn't give someone an
awareness of what the sensation of blue is like, even if you can't
imagine what it's like to eat a live squid.  You know that solving the
Schrodinger equation for an NH3 molecule wouldn't give it to her either,
even if that procedure is much too complicated for you to clearly
imagine.  The point is just that you have some latent understanding of
how things work, which thought experiments bring out.  It is beside the
point that the complete description of the brain is unknown to us now,
since going through the TE shows we know that that *sort* of information
is irrelevant for understanding the sensation of blue.
 
Finally, I think you know that if I said to you, "You will now raise
your left arm," you would be able to refuse.  You also know that if I
told you to raise your left arm and I simultaneously balanced a
basketball on my head, you would still be able to refuse.  You know this
even though the situation has never happened.  Now, however it is that
you know that, is how you know all similar facts, such as the fact that
if I did a bunch of mathematical calculations and measurements on you
first, you could still refuse to raise your arm.  I don't see how your
knowledge of what would happen in Bryan's thought-experimental situation
is supposed to be any more problematic than your knowledge of any
counter-factual conditionals.
 
What thought experiments do for you is show you when you have let your
philosophical theories get disconnected from your common sense
understanding of how the world works.