From stapp@thsrv.lbl.gov Fri Dec 11 13:23:01 1998
Date: Fri, 11 Dec 1998 12:56:37 -0800 (PST)
From: Henry Stapp
To: Pat Hayes
Cc: Brian Josephson , Aaron Sloman ,
brings@rpi.edu, brucero@cats.ucsc.edu, chalmers@paradox.ucsc.edu,
ghrosenb@ai.uga.edu, jmschwar@ucla.edu, keith@imprint.co.uk,
patrickw@monash.edu.au, klein@adage.berkeley.edu
Subject: Re: Classical vs Quantum
On Fri, 20 Nov 1998, Pat Hayes wrote:
> >--On Thu, Nov 12, 1998 0:57 +0000 "Aaron Sloman"
> >wrote:
> >
> >> Nothing Brian has written implies that facts of chess are derivable from
> >> laws of physics (in such a way that the laws are essential to the
> >> derivation, and not spurious additions.)
> >
> >It would help, actually, if someone explained exactly why the derivability
> >question is of interest.
>
> The intellectual history is this. Henry Stapp's argument (concerning the
> relationship between classical physics and consciousness) has the following
> form:
>
> 1. Classical physics only mentions certain kinds of property ('geometric'.)
> 2. Therefore, an assertion is derivable from classical physics only if it
> also only mentions (or can be expressed using) such properties.
> 3. Certain salient facts about consciousness do not mention (or cannot be
> expressed using) such properties;
> and therefore
> 4. These salient facts about consciousness are not derivable from classical
> physics.
>
I would put it this way:
1. Classical physics restricts only certain kinds of properties
('geometric'). [CM does nothing but place conditions on the allowed
(by nature) forms of the purported trajectories of (invisible) particles,
and on the consequent allowed observable changes in locations and shapes
of the observable objects and systems purportedly made up of these
particles.]
2. Therefore, an assertion is derivable from classical physics only
to the extent that its truth is LOGICALLY determined exclusively by
constraints on these (geometric) properties.
3. Certain salient features of consciousness [e.g. pains, colors] are,
within the logical structure provided by classical physical theory,
not logically constrained by such (geometric) restrictions.
4. Thus these salient features about consciousness are not derivable from
the principles of classical physics alone.
> There are several problems with this argument, but it clearly is centrally
> concerned with assertions following from others, and restrictions on this
> relationship which (it is claimed) arise from restrictions of vocabulary.
I am not sure that "vocabulary" is the best term. The restriction is
conceptual: classical mechanics deals with a limited set of concepts,
namely motions in 3-space of particles, and systems of particles. This
is an abstraction from a very limited portion of "experience space".
The issue is the claimed limitation in the logical or mathematical
consequences of the principles of classical physical theory
that follow from this extreme narrowness of its conceptual base.
> Now, this area is one that has been thoroughly studied by logicians and has
> for the last half a century or so 78moved from the cloudy regions of
> ordinary-language philosophising to the more exact territory of
> mathematics, where theorems can be proven about it. So a certain passing
> attention to these theorems can reasonably be demanded of those who venture
> such arguments.
>
> When one applies this degree of rigor to the above argument one finds a
> crucial flaw: it depends on what one means by "derivable from" in lines 2
> and 4. In one (narrow) sense, the argument is correct, but then in that
> sense it applies not just to consciousness but also to almost all of human
> knowledge other than basic physics (that's where the theorems come in),
Classical physics allows predictions to be derived about a wide variety of
things: much of nineteenth century engineering can be derived from
classical models, as can the behaviors of computing machines that are
adequately representable within CM. That's a lot of territory, but it
does not extend to the non-geometric aspects of human experience:
the "painfulness" of an experiences is not logically prescribed solely by
the geometric limitations imposed by the principles of CM.
> so
> the conclusion does not seem to bear very centrally on a discussion about
> consciousness.
I demur: A massive amount of interesting and important conclusions about
behaviours of physical systems can be deduced from the restrictions on
behaviour of physical systems imposed by the principles of classical
physics. But the "redness" or "painfulness" of certain experiences are
not deducible solely from the standard principles of CM.
> In a different, wider, sense of "derivable from", the
> argument fails on at least two counts. First, in this wider sense, 2 does
> not follow from 1; and also 3 may well be false: in fact, the only way
> something of the form (3) could be justified (using this wider sense) is
> from a complete enough understanding of the nature of conciousness; which
> we notoriously do not, at present, have.
>
> The relevance of chess is as an example of the failure of the inference
> from 1 to 2. The rules of chess obviously cannot be derived from physics,
> and they are not logically necessary (if they were, checkers would be
> impossible.) Yet one does not conclude that an explanation of chess must
> somehow involve a rejection of classical physics.
>
Classical physics is not being "rejected": it is being "restricted" to do
only what it is structurally and logically able to do. It covers how the
chessmen will bounce around on a bumpy train ride, and it would cover the
behavior of a classical computing machine that has been programmed to play
chess. But it will not fix the rules of chess, as enunciated by their
inventor, unless it is applied to the brain of the inventor of these
rules, and the initial conditions of this brain state are given.
> What Aaron seems to be saying is that chess is in
> >a clear sense arbitrary, which I accept. As regards photosynthesis there
> >are senses in which it is arbitrary and senses in which it is not, so where
> >do we stand?
>
> Thank you; precisely my point. In one sense, using the narrow, purely
> logical, sense of 'follows from', it is arbitrary. In a wider sense (in
> which the machinery of photsynthesis is taken to be part of the very
> meaning of the term "photosynthesis") it is not arbitrary. Maybe
> consciousness will also turn out to be a matter which can be accounted for,
> in some ultimate sense, in what Henry calls 'geometric' terms. Until we
> know more about consciousness we cannot possibly know whether it will or
> not.
>
> Pat
>
We already know enough about consciousness and about classical mechanics
to know that the occurrence or nonoccurrence of the painfulness of
an experience is NOT LOGICALLY ENTAILED solely by the standard principles
of classical mechanics in conjunction with a complete description of all
the spacetime trajectories.
The WHERENESS of the "redness" or the "pain" is experientially different,
---now, and to a child of five---from the "redness" or the "pain" that is
located THERE. These aspects, geometric and nongeometric, that can be
experientially distinguished today, are not going to become
indistinguishable as we learn more: we are not going to become unable
to see that the "red" spot lies ABOVE the "green" spot.
Classical physics is based on a certain very narrow part of our
experiential space, and it is designed to place restrictions on our
experiences in that narrow domain. We can certainly add on extra
parts: a temperature of 110 degrees Fahrenheit FEELS HOT, to most of us
under otherwise normal conditions etc. But these extra add-ons are not
derived from classical physical theory alone. Yet the rate of acceleration
of a falling apple is!
Mathematics is my game/profession. If you have a theorem that is relevant
please state it, and the relevant definitions in terms of which it is
defined, and how it is to be applied to the present case. Theorems are
often misapplied. They can only put out what is put in. In the present
case we are dealing with a (in fact false) theory about nature that is
constructed on a very narrow aspect of our conceptual experience, namely
our experiencing of objects as being in locations in 3-space, and moving
from location to location with increasing time, and of an abstraction from
that aspect of our experience: the notion that the objects that we sense
are constituted out of tiny particles that move on restricted classes of
trajectories in 3-space.
This conception is "objective" in the sense that there are the objects
being sensed by observing systems (ourselves), and these objects being
sensed by us are supposed the HAVE these specified geometric properties,
independently of what the various observing systems are experiencing.
When we allow an observing system S, one of us, to be also an observed
system we have in principle two different descriptions of that system S:
(1) its theoretical description in terms of the geometric concepts of CM,
and (2) the actual experiencings that belong to the observing system S as
it observes some system S' (which could conceivably be S itself).
So one has three descriptions: the geometric (CM/theoretical) description
of S, the geometric (CM/theoretical) desscription of S', and the
description of what the system S is experiencing as it observers S'.
The observing system S can use a rich vocabulary, rooted in primitive
theories and conventions, to identify the system S' that it is observing.
But the only observable features of S' that classical mechanics recognizes
or restricts are changing locations and shapes: the motions of parts in
3-space. The same goes for the CM description of S. The vocabulary that S
uses to describe what it is experiening as it observes S' is far richer:
it includes the terms "pain" and "sorrow" etc. that are not included
in the standard concepts of classical mechanics.
There may well be, empirically, correlations between experiences
described in these non-geometric terms---e.g., colors and pains--- and
certain geometric aspects of S and of S', as these aspect are conceived of
in classical theory. But the issue is whether there is some mathematical
proof that indicates how one could deduce, solely from the principles of
classical physics, which deal exclusively with theoretical changing
occupancies of locations in 3-space of particles and systems, and our
experiences of such changes, any LOGICALLY NECESSARY connection between
these CM geometric aspects of S and the non-geometric aspects of the
experiencings that belong to S.
I regard it as certain (while awaiting your proof that I am wrong about
this) that no mathematical proof could show, within the framework provided
by the principles of CM, that the restrictions on geometric properties
entailed by CM could logically entail restrictive assertions on the
nongeometric aspects of experience, such as "color" and "pain":
the ingredients needed for such a proof are, I believe, clearly absent in
the problem posed.
In thinking about this issue there is a clear danger in theorizing about
it in terms that are too abstract: the abstraction is liable to eliminate
precisely the detailed restrictions that are essential to the actual case
at hand. One must apply any abstract consideration to the restrictive
actual case at hand, in order to demonstrate the relevance of this
consideration to the very special case of classical mechanics.
I believe that a great deal of obfuscation has occurred in the discussion
of "physicalism" and "identity theory" by insufficient care in the
definition of "physical": the ideas of classical mechanics are taken over,
but only in a loose and imprecise way, without sufficient rigorous in the
definition of "physical". Clearly, a sufficiently loose definition would
not exclude consciouness. Indeed, quantum mechanics shows how the physical
and mental aspects of a "physical" theory of nature can become enmeshed if
one drifts away from strict CM.
My approach is to pursue this superior theory that features enmeshment,
and clarify it, rather than adhere, mindlessly I think, to a false theory
that has arisen from the exclusion of mind from our theory of nature.
Henry