X-Message-Number: 11502
From: Thomas Donaldson <>
Subject: For John Grigg, and on computers versus intelligent creatures
Date: Wed, 31 Mar 1999 00:24:26 +1000 (EST)

Hi everyone!

So here is TKD, once more.

To John Grigg: I've summarized these ideas in a previous posting, but 
perhaps you weren't watching then. Basically, no one has to think of
cryonics as freezing the "dead". Cryonics depends on a different
DEFINITION of death, not on the notion that we will someday be able to 
revive dead people. And our definition is better: the current definition
depends quite thoroughly on the technology and understanding of the time,
while ours depends on much more absolute criteria. Cryonicists believe
that you are dead if NO FUTURE TECHNOLOGY will ever be able to revive you;
the current common definition believes that you are dead if no one NOW 
can revive you.

If your body has been totally destroyed, we would agree that you are dead.
But there are cases in which we can even believe that you are dead when
the usual definition does not: specifically, diseases and injuries which
destroy the major part of your brain, even if they leave those lower areas 
responsible for breathing and heartbeat untouched.

So what does this tell you? If you come to agree with our definition of 
death, then NOT to be suspended is a violation of God's commandments. It
is only the backwardness of the 20th Century which would claim that their
definition of death is the same as that of God, and so you violate God's
will if you try to live on. If God is merciful, then all those who truly
believe that definition will not be punished for their belief --- but
if you come to believe in cryonics, that may raise questions. Do you
really believe that God will adopt the definition of death worked out in
the 20th Century by human beings living on one planet amid a vast 
universe?

And on simulation versus reality, for Mike Perry: I will ignore the issue
of quantum behavior, mainly because everything I know about how our brain
works suggests that quantum theory plays the same role in our brain as it
does in a diesel engine: it's usually irrelevant. 

It is not even clear that the thoughts of a simulated human should count
as real thoughts. Basically, simulation involves the construction of 
a computer program (or object) which imitates a real object SYMBOLICALLY.
No one believes that they will be seriously hurt if they crash a simulated
airplane; the basic point Searle was making was that we can play with
symbols according to various rules all we want, but those symbols (and
our play) says nothing about the world unless we explicitly AND SEPARATELY
identify the behavior of the symbols with something about the world.

(Yes, I've pointed out before that a symbolic system just might be so
extensive and so complex that it could only be identified with the real
world in one way --- but proving that claim by experiment takes far more
than simply asserting it to be true). 

If we do not carry out that identification, or perhaps carry it out
wrongly, then we are only playing games with symbols. Any conclusions we
reach mean nothing. Not only that, but if a simulated human being has
simulated thoughts, those thoughts themselves mean nothing unless a REAL
human being (or other REAL CREATURE) identifies them with thoughts and
assigns meaning to the trains of symbols of which they consist.

Present computers are fine machines for dealing with symbols. And what I
say here does not mean that we cannot use IDEAS from computer science to
build an intelligent creature (whether it's a computer depends a lot on
your definition of a computer; it seems to me that you'd also have to
decide that humans are computers, too). Certainly this creature would 
have to do much more than have thoughts; it would have to do things in
the world. And its relationship to the world and the objects in it
would not be the relation of symbols to reality, but much more direct.
If it picks up a book, it does not pick up a symbolic book but a real
one. And at the root level, its thoughts are reactions of its brain
systems to the world, not arbitrary symbols but reactions resulting from
the structure and connections of its brain to its senses. 

Nothing in physics suggests to me that such a creature could not be
built. After all, we ourselves are such creatures. But it would have to
do much more than simply operate with symbols.

			Best and long long life for all,

				Thomas Donaldson

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=11502