Dear All:                                          Nov. 6,1999

I have returned, and have studied the contributions to this thread 
from its beginning with Aaron's Sept 5 answer to Stan  until its end with
Aaron's Oct 17 answer to Stan. I shall answer here the key questions
addressed to me by Pat and Aaron. 

I affirm that the question at issue is a logical one. It is:

How can the notion of ``entail'' be understood in a way that allows one 
to claim, validly and rationally, that, within the framework of classical
physical theory (CPT),
 

1) Micro-physical facts can entail such macro-physical facts as 
   hurricane facts, and airplane facts, and locomotive facts,

but

2) Micro-physical facts cannot entail the existence of
   felt qualities such as painfulness and
   subjective (phenomenal) redness. 

I shall answer this question paying close attention to the very reasonable 
points raised by Pat and Aaron during the six weeks of discussion.

First there is the question of ``de re'' versus ``de dicto''
raised by Aaron's Sept 26 message: He asks whether I am speaking about a 
fixing or determining of `actual facts of nature' by other `other actual 
facts of nature', or, instead, about logical implication within a theoretical 
framework. 

The answer is definitely the latter. We know that the world itself is 
definitely not describable in terms of the concepts of CPT: that framework
is an invention of man that is contradicted by the facts. Hence the 
entire logical structure under consideration must be understood as existing  
within a certain theoretical framework that is known to be incompatible
with nature herself. 

The issue is about logical implication within this specified theoretical 
framework: it is stricly ``de dicto''.

When I speak of the `description of the microphysical facts', I am doing
so from the perspective of a theoretical physicist who is using CPT: 
the complete description of the `microphysical facts', within the 
CPT framework of thought, is supposed to be a complete description of the 
trajectory in spacetime of every particle in the universe, and also the 
description of the value of every physical field at every spacetime point. 
This (imagined) micro-physical structure is one key component of the 
theoretical framework that constitutes CPT.


Newton, in ``Principia'', tied the micro-physical description to macroscopic
phenomena, such as the tides, which properly trained people can observe.

Classical physical theory is used by scientists to form useful and
testable predictions about all sorts of observable phenomena, from
meteorology, to aerodynamics, to steam engines. So how is this
theoretical construct, which is expressed in terms of microscopic 
properties invisible to human beings, connected to our actual and
possible experiences about the world.


Classical physical theory is erected on idealizations of certain aspects
of the complex and many-faceted image of the physical world that arises 
in our stream of consciousness. Descartes,  who was not only the founder 
of modern philosophy, but the also the creator of analytic geometry, 
picked out the GEOMETRIC ASPECT, namely the features characterized by 
extension in space and time, as the basis of a conception of 
`that aspect of nature that persists when no one is experiencing it'. 
According to this conjecture of Descartes, there is an aspect of nature 
that exists outside of anyone's experience, and that aspect has a 
microscopic spacetime structure: it can be described in terms of properties 
assigned to spacetime points. 

This conceptualization is based on idealizations that were already the 
basis of Euclidean geometry, namely the idealized zero-size limit of
small regions of the kind that we can actually observe, namely points,
and the similar idealized limits of visible lines. Since these basic 
geometric elements are idealizations of shapes and regions of the kind we 
can experiences, one had a logical basis for linking the idealized
theoretical constructs to real and imagined experiences.

The geometric aspect of our experience is  woven into a much richer fabric: 
it does not stand isolated and apart from the rest. Yet we can say that 
the tide is higher today at noon than it was yesterday at noon; or that the 
moon is higher in the sky tonight at midnight than it was last night at 
midnight etc.: conditions on relative locations can be specified. 

Of course, these descriptions are not infinitely precise.
One builds machines that are milled to specified tolerances: exact
specifications are neither possible to meet, nor needed for practical
applications.

Properly trained technicians know how to recognize and report whether 
the tide is higher today at noon than is was yesterday. It is via statements 
that impose geometric conditions of this kind that CPT can be tested, and
applied

The specifications must, of course, fit the characteristics features of the
phenomena being described. The geometric properties used to specify
the pertinent physical properties of hurricanes and airplanes and 
locomotives will be different: for hurricanes properties like barometric
pressure and wind velocity would be appropriate, for airplanes the shapes 
of the wings, for locomotives the shapes of the pistons. These sorts of 
descriptions, which are based on what properly trained technicians can
know about the system or object in question, provide the foundation for
entailments of type 1), mentioned above. But the only features of 
phenomena that are tied in this way to the micro-physical facts, 
as represented in CPT, are geometric features. Everything else gets
left out: the nongeometric features of phenomena are woven onto our knowings
in intricate and important ways, but, they lack the connection to 
the basic CPT geometric microphysical elements  that arises from the fact 
that those micro elements are idealizations of the macro-geometric 
aspects of our knowings 

The sense in which certain microphysical facts can entail certain 
macro- geometric facts is this: Suppose Y is a statement that specifies 
certain conditions on some macro-geometric properties that characterize 
observable features of some macro system. Suppose X be a statement that 
asserts that the physical world, as described in CPT, satisfies a certain 
set of microconditions. Then X entails Y if and only if no possible CPT
world can satisfy X and not satisfy Y.

CPT includes not only the basic micro-physical descriptions: it includes, as 
any physical theory must, also the rules for how these descriptions are linked
to our observations. Otherwise the theory would be devoid of physical content. 
The rules of interpretation of CPT are based in the fact that
the micro-concepts of the theory are idealizations of macro-geometric
aspects of our human experiences, and the principle that large aggregations 
of microscopic elements can define observable macroscopic shapes.

The painfulness of a pain-experience is not characterized by a shape. Nor is
the redness of a conscious red-experience. Human experience has dimensions
or aspects that are not shape-like. A flute is experienced as having a shape,
but the conscious experience of a musical note (a high C) has a quality 
that is not the conscious experience of a geometric shape.  

Since the nongeometric aspects of our knowings do not have this conceptual
link to the microphysical facts there will be no comparable entailment 
of nongeometric features from the micro-physical facts, insofar as the
analysis is confine within the framework of CPT.

So there is, within the framework of classical physical theory,
a ``principled distinction'' between the geometric and nongeometric features
of human experience. This principled distinction allows statements that 
place conditions on microscopic facts to entail such things as 
hurricane-facts and locomotive-facts, yet be unable to entail 
redness-facts or painfulness-facts. 

Aaron (Sept 5) asserts that propositions about mental states are 
LOGICALLY disconnected from propositions of physics. This is in line 
with the conclusion that I obtained above. But I obtained my conclusion
ONLY within the framework of the provably false CPT!

Aaron (Sept 5) suggests that, inspite of this LOGICAL disconnect, the 
two realms are CAUSALLY connected. 
[Hence his title: logical vs causal connections.]

This raises the key issue: Should an adequate physical theory express the 
CAUSAL structure of nature in logico-mathematical terms?

The aim of CPT was certainly to do this, at least part. However, it was 
deficient from the outset, because it did not include our conscious  
experiences within the causal structure. And it ultimately failed to fit
the physical facts.

Aaron's approach is just the opposite of Crick's and the identity theorists,
who want to say that consciousness is `nothing but' physical brain activity:

Aaron's idea is rather to accept the idea, exhibited by CPT, that there
is a LOGICAL disconnect between mental and physical aspects of nature,
but to assert that there is a CAUSAL connection between these two aspects
that is not expressible as a LOGICAL connection.. 

But why abandon the effort to formulate this causal connection in logical
terms. Maybe a more complex logical structure will do.. Apparently Aaron
believe that there is some basic inadequacy of logical thinking that must
forever prevent the causal connection between the mental and physical aspects 
from being expressed in a logically coherent way? This commitment runs 
counter to the aims of Western science, though it is perhaps in line with 
Eastern traditions. 

Quantum theory is, of course, precisely an expression in logico-mathematical
terms of the causal structure of the interpenetrating physical and causal
aspects of nature. And it has the virtue of resting securely on thousands of 
nontrivial theoretical and experimental findings.

Aaron suggests that I try to avoid the logical disjunction by bringing
in mentalistic language. But if one is seeking to bring together the
mental and physical aspects of nature, which CPT split asunder, should one 
not accept the appropriate two languages and show how the propositions in 
these two languages can be interpreted as parts of a coherent
combined language? 

One can surely say a great deal about conceptual things, such as the rules
of chess, without ever trying to establish what the causal connections are
between what we are thinking about when we think about these things and what
is going on in our brains. But if we DO want to inquire about these mind-
brain connections, which is the endeavour that is behind this whole discussion,
then I see, at present, no  sufficient reason to reject the Western science 
aim to comprehend the causal connection in logico-mathematical terms.
The failure of the false concepts of CPT is hardly a good reason to abandon
this worthy goal. 

In view of the inadequacy for this task of the empirically false  CPT, 
the most reasonable thing to try next is the empirically valid physical 
theory that has replaced it, which in its original and most most natural 
forms brings mental events directly into the causal structure, within 
a coherent logico-mathematical framework.  

Henry