Pat Hayes posted the following note (26 Aug 1996 11:03:28):
*******
Subject: Re: QM in Stapp&Sarfatti vs Hameroff and Penrose
To: Multiple recipients of list PSYCHE-D
..... the argument that somehow it follows
>> from classical physics that there can be no functional role for
>> consciousness.
Could anyone articulate this argument carefully, or give a reference to
such an articulation? (Eg from which part exactly of classical physics is
this remarkably unphysical-seeming result derived? Is it something to do
with thermodynamics, or is it best understood in terms of electromagnetism?
Etc...)
Why would any such argument not also apply to almost anything with a
functional role describable at a large enough scale that quantum effects
could usefully be ignored, eg (say) a leaf, a carburettor or a brick wall?
None of these structures can be predicted within classical physics (ie they
cannot be derived from Newton's laws of gravitation, Maxwell's equations,
etc.).
Analogous arguments to Chalmer's dancing qualia can be given for anything
that can be progressively dismantled (eg consider replacing each brick by a
metal block and ask when exactly it ceases to be a brick wall), and
analogous arguments to the zombie nonsense can be given for anything (eg
consider something which is constituted exactly like a brick wall but is
not, in fact, a brick wall: suppose for example it simply appears,
spontaneously, in a long elliptical orbit around Jupiter. This is
*logically* possible. It must follow then that the essence of
brickwall-ness is somehow separate from the physical nature of the wall
itself.)
Pat Hayes
*******
By classical physics is meant here the premise that: 1), there is a description
of the physical world in terms of localizable quantities, namely the locations
of all the particles in the world, and the values at all points in the world of
all the local fields, such as the electromagnetic and gravitational fields; and
2), there are some laws of motion that are local in the sense that they
determine the rates of change of any quantity localized at some point in terms
of quantities localized in a open neighborhood of that point, where this
neighborhood can be taken to be as small as desired; and 3), these laws
determine in principle all the values of all these localizable quantities at
all times, given the values of all these quantities at times earlier than some
early specified initial time T_0.
These localizable quantities are called the basic physical variables. Any
quantity defined unambiguously in terms of these basic variables can be called
a physical variable, and various mathematical properties of these physical
properties can be deduced from such definitions and the laws of motion.
For example, a thundercloud can be defined to be `angry' when its electrical
potential relative to the earth or nearby clouds is higher than some specified
amount, and the behaviour appropriate to an angry thundercloud, such as
releasing thunderbolts, can be predicted on the basis of the definitions and
the laws of motion. But can one deduce from these laws and definitions whether
or not the cloud feels like you feel when you are angry?
The answer is no! There is a logical disjunction between (1), the set of all
assertions about physical behaviours that are strictly deducible from the
mathematical laws of motion plus the mathematical definitions of physical
properties (in terms of the basic physical quantities) and (2), the set of
empirical facts about our experiences. The former set of assertions live in a
world of mathematical abstractions: what lies in this set is determined by
mathematical and logical principles alone. There is no logical principle there
that entails anything about what the actually experientially felt realities
are. These realities could be totally nonexistent without violating any of the
mathematical properties.
But if the empirical/experiential realities could be totally absent, without
affecting the classical mathematical/physical/causal structure, then the
former realities are not causally efficacious: they are epiphenomal. Nothing
physical changes if they are left out.
[On the other hand, quantum mechanics, adequately formulated, is based on
experiential realities, which therefore cannot be simply left out without doing
violence to the basic logical structure.]
Hayes asks:
*****
Why would any such argument not also apply to almost anything with a
functional role describable at a large enough scale that quantum effects
could usefully be ignored, eg (say) a leaf, a carburettor or a brick wall?
None of these structures can be predicted within classical physics (ie they
cannot be derived from Newton's laws of gravitation, Maxwell's equations,
etc.).
*****
Yes, it would apply: What the leaf and the carburettor and the brick wall are
experiencing or feeling plays no causal role within the classical physics
description of nature: the *physical* properties of these things completely
determine their behaviour, with no effects from the analog, from the
perspective of those items, of our empirically experienced reality. According
to the principles of classical mechanics we can, in principle, deduce from the
physical properties and laws how the carburettor will behave without knowing
anything at all about how it is feeling.
Henry P. Stapp [http://www-physics.lbl.gov/~stapp/stappfiles.html]