X-Message-Number: 3917
From:  (Joseph J. Strout)
Subject: SCI.CRYONICS Re: Symbols & Substance
Date: Mon, 27 Feb 1995 12:32:42 -0800 (PST)

Robert Ettinger () wrote some reasonable arguments for
the notion that uploading one's subjectivity may not be possible...

> Certain (largely unknown) aspects/activities of the brain constitute mind,
> and in particular FEELING, the ground of being and sine qua non of
> consciousness or life-as-we-know-it. According to the uploaders, mind can
> exist--in principle--in any computer, including Turing's paper tape. In other
> words, they claim that mind, including feeling, consists of symbol
> manipulation and nothing else. They seem to think this is self-evident,
> whereas others of us think it is not only not self evident, but very possibly
> (at least)  not true. 

We should probably define this assertion as "strong uploading," which
is doubly meaningful due to the assumption of strong AI.  The more
reasonable view, then, we'll call "weak uploading," which asserts that
the mind can exist in an artificial device.  No explicit description
of the device is required by this claim, though we may conjecture
freely about what properties of it are possible, desirable, and
necessary.  I suspect that it will be a highly parallel device, rely
mostly on optical or electrical interactions, be adaptable, and
(unlike current biological brains) be physically sustainable without
complex metabolic processes.  We could argue over any of these
details, but none of them are vital to the central assertion of weak
uploading.

> Further, we can postulate possible physical/physiological requirements for
> feeling and consciousness. As a very crude possible example, maybe feeling
> requires a "self circuit" which consists basically of a kind of standing wave
> in/among a set of neurons, the wave being manifested (say) as electric
> current. It "likes" certain states and boundary conditions and "dislikes"
> others. (The "like" and "dislike" are very literal, because the
> conditions/perturbations DEFINE or CONSTITUTE the organism's feeling of
> satisfaction or dissatisfaction, pleasure or pain.)

Many such scenarios are conceivable, but until we have some evidence
of it, it unparsimonious to suppose that it's the case.  Very complex
behavior can be generated by elements even simpler than real neurons.
(I'm using "behavior" in the dynamical systems sense, i.e., the
evolution of system variables over time.)  This complexity arises
"simply" from the interconnection of a large number of relatively
simple elements.  I know of no reason not to suppose that such internal
signals give rise to feeling, and also generate a model of the world
and ourselves which gives rise to consciousness.

> Note that time could be crucial. Perhaps the various parts of the standing
> wave signal to each other at the speed of light, but chemistry is also
> involved. A physical analog may not be possible, which COULD mean that only
> meat can feel, or that only a limited set of physical substrates can support
> mind.

It seems unlikely that only biological cells can feel, but reasonably
likely that only certain physical substrates can do it, or (at least)
do it in real time.  For example, if quantum interactions are
necessary (which, mind you, I doubt), then conventional computers may
not do the trick, but we can build quantum devices which could.

> Returning again to the putative possibility of finding a physical analog to
> any given physical process, consider ordinary classical elctromagnetic
> phenomena.  An electromagnetic wave travels at the speed of light in vacuum,
> the electric and magnetic fields are at right angles to each other and to the
> direction of propagation, Maxwell's equations are satisfied, etc. Does--or
> could--any other physical phenomenon share these attributes? Probably not, in
> which case an e.m. wave can do things that nothing else can do, INCLUDING
> certain types of information processing in real time and space.

True, but (though I hate to sound like a Strong Uploader), a
simulated e.m. wave can (in principle) do anything in simulated space
that a real one can do in real space.  Though it may require a source
of random numbers to do it.

> But it may NOT be possible to replace the subjective circuit itself with
> ANYTHING that will fill the bill. 

What you say is distantly conceivable, but it seems to give
unwarranted credit to cells.  Most of what cells do is concerned with
staying alive.  Much of the structure and activity in a neuron is also
directed at staying alive, but oh (by the way), they can also transmit
signals (like all cells) and are connected in a way that results in
thought and feeling.  To suppose that the thought and feeling actually
*require* all the metabolic baggage which are our evolutionary
inheritance seems superfluous.

Joe Strout             Neuroscience, UCSD            

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