Dear Pat,                                                 April 3, 1997

The new title (Principled Distinctions) is appropriate: it pinpoints
the issue before us, which certainly is *the* critical issue, and it
signalizes that we have moved---at last---beyond the stage of talking 
completely past each other. 

Although you do not yet see my main point, I think you will.

By way of preparation let me first provide a little more background about
where I am coming from, because I think your tendency to identify my position 
with one's you have heard before has been the main cause of our inability to 
communicate.

I believe the position you usually contend against is based on an
*implicit* acceptance of a `classical-type conception of nature', and that
that position you oppose is not defencible, logically, until that
implicit presumption is made explicit. However, once that implicit
assumption is made explicit then that explicit `classical' premise does
provide the rational basis for the needed principled distinction.

The other key element in my own thinking, which is based mainly on my 
study of the lesson's taught by the Einstein-Bohr debate, is to see science
as a human endeavour: as a social process in which our language and concepts
evolve by trial and error, and by elaborations of hunches. It resides in 
the collection of conscious thoughts of the community of communicating 
human observers and scientists. The `observed facts' are represented within
this body of thought by the articulated assertions of trained and qualified
observers pertaining to what they have done and what they have learned. 

First some clean-up.
I said:
>the classical conception asserts that this `complete classical physical
>description' does exist.

You replied:
"Really? Where is it supposed to be written, and in what language? Or
perhaps you mean only a mathematical sense of 'exists': but then you should
be a little more careful about what you mean by 'description'.

My statement
>the classical conception asserts that this `complete classical physical
>description' does exist.

stated in more detail would be this:

the classical conception of nature asserts that there does exist a physical
world that is in principle describable in the language of classical physics
and that this existing world is part of a world history that extends from 
the infinite past to the infinite future and conforms to all of the principles 
and laws of classical physics. The precise form of these laws may or may 
not be known now to human beings, but they are in any case fixed in nature,
and are similar in essence to contemporary classical physics. 

But the question is: How is this assumed physical world connected to
our experiences, and to  articulated facts about it?

You say:
"But I think we can put this subdebate to rest, since it seems to have been
based on a misunderstanding about what 'the classical conception' means.
Lets agree that it amounts to far more than classical PHYSICS, but includes
a complete PAF description of the entire history of the universe from start
to finish.

"It still doesnt use the term 'leaf', notice. However, I think I comprehend
you now rather better.  Your point, if I finally comprehend it, is not that
this complete description entails any macroscopic descriptions, but rather
that it entails that the trained observers (who are themselves part of the
described PAF plenum) will report their observations in a certain way:"
 ...

"So it is the OBSERVERS BEHAVIOR which would be entailed by a complete
classical description, not the content of what they say in their
experimental reports. That makes much more sense."

One might interprete Bohr as a behaviorist, and believe that when he 
says:" we can tell others what we have done and what we have learned"
he is merely speaking of a bunch of unconscious robots muttering
sounds.

Behaviour is *part* of the story: communication does require a behaviour.
But to see *only* the behaviour is to miss the essence. The human activity 
in question is basically a process that is occurring in a realm of human 
conscious experiences. The physical theory is itself a collection of
experiences, as are the empirical experiences that the observer reports.
And these experiences are expressed in verbal statements that purport to 
represent certain facts about the world: the meaning of the content of the 
reports feeds into a behaviour that creates *articulated facts* in the realm 
of human consciousness. These statements are what logic deals with. So
what is at issue here is the creation of the statements that logic 
manipulates, and also the very process by which the logicians and the 
mathematicians come to recognize and to manipulate the symbols that 
are the tools of their trade. So I am considering the problem from the 
meta level of the ontology within which the logical process---a human 
activity---occurs. I see this as the Bohrian level of analysis.
So the entailment is not only a physical process but also a logical
one, because a mathematically described situation in one domain, namely 
the domain of the actual physical reality---which due to the assumption 
of the correctness of the classical conception of nature is isomorphic 
to an infinite collection of overlapping possible human conceptualizations 
of it---becomes described within a verbal human language.
......

I said:
>*Entailment* from the complete classical physical description plus the
>Bohrian theory of experiment into the world of human experience means
>the process of injecting articulated facts into the realm of human
>discourse by means of the capacities of human observers to experience
>macroscopic properties that: (1), are carried by the PAFs,
>and (2), they have learned to recognize and report about.

You said:
"OK, I finally get this point. However, let me suggest that you find a way
to rephrase your thesis. You really shouldnt call this 'entailment' without
providing a MUCH more careful description of what you intend to mean, as
this a COMPLETELY NEW kind of entailment. Roughly, A Bohr-entails B if it
follows from A that someone will truthfully utter 'B'. (It might be
interesting to investigate the logical properties of this, which seem most
unusual. It's not transitive, for one thing, which rules out
straightforward semantic approaches.)"

It cannot be transitive because it is from the physical realm, as
that realm is conceptualized in classical physics, to the realm of 
articulated statements. 

You said:
"OK, now we can leave aside all the 'entailment' discussion ( I will just
note from now on where you use this word in a potentially misleading way,
but I understand what you mean by it, at last. I hope ...;-)

"Now, however, I STILL can't detect the 'principled distinction' you insist
on seeing somewhere.

"Pat

"[continued...]"
 
Yes, you still are not seeing what I am seeing, for your words simply 
repeat things that I myself have already emphasized, and that are
already encompassed within my thought:

I have already stressed that we see the color of the leaf much on a par to
experiencing its location and shape,  and that we hear the pitch of the horn 
much on a par to sensing its location and shape. And I have already stressed 
that we can make errors in judgement as much about locations and shapes as 
about colors and pitches. In bringing up these points you are arguing 
against someone else in your past experience, or against some other 
position you may have heard expressed, not against me or mine. These 
differences/similarities, although often brought up by others, have nothing 
to do with the principled distinction that I am talking about. So I ask you to
examine what *I* am saying.

The principled distinction lies in the fact that classical physics has elected
to erect itself (or the scientists such as Galileo, Descartes, Newton, & 
Maxwell who have created it have erected this conceptual edifice) *upon 
idealizations of our experiences of location and shape*, rejecting as 
elements of this edifice the other aspects of our experience that come to
us all intertwined with, and more or less on a par with, our experiences 
of location and shape. Thus the description of the PAFs is in terms of
idealizations of positions of stars and apples and cannon balls, familiar 
from our everyday (and clear-night) experiences. The experiences we have of
the locations and shapes of objects are, as a matter of historical
fact, used differently in the construction of classical physical theory 
than our experiences of color and pitch. I do not cite John Locke, and his 
primary and secondary qualitities, as an *authority* on what is true and 
correct about our understanding of nature, but he did correctly identify 
this  particular features of the classical conception of nature that
is, by now, so ingrained in the thinking of educated people as to render them
almost unable to see it as a profound assumption that should be made explicit.
This extraction and elevation of this particular aspect of our experience is 
certainly is AN aspect of the classical conception of nature, and I would say
is, in fact, THE underlying presumption of the classical conception of nature.

You asked:
>>What singles out 'matching of spacetime forms' as the crucial kind of
>>observation? Is this supposed to be an empirical claim about the way that
>>experiments are conducted? It seems entirly ad-hoc and arbitrary, since the
>>complete physical description predicts many other observable aspects of the
>>world.

I answered:
>
>The basic premise of the discussion is that the classical conception of
>the physical world is correct. But this classical conception is based on
>the conception or notion of *forms existing in spacetime*.

You responded:
"It is based on PAFs. These might be forms in spacetime, to be sure, but
THESE forms cannot be perceived directly. They are just as inVISIBLE as
sounds and smells (and degrees of happiness.) And on the classical
conception, these spatiotemporal forms 'carry' all kinds of perceptual
reports. So I repeat, what makes macroscopic spatiotemporal sightings
different in principle (in the classical conception) from any other
perceptual reports? (Answer: nothing.)"

My point is that according to the classical conceptualization
the physical world is built on spacetime forms that are idealizations of
the *spacetime forms* that we experience in everyday life. It is not built
on the other intertwined aspects of our experience. The spacetime forms of the 
PAFs, in the complete classical physical description on nature, entail, 
within that mathematical structure, large scale spacetime structures of 
visible (for example) size, and these large-scale structures are of the
same conceptual kind as the large-scale spacetime structures that were
idealized to form the theory. One can also build from the PAFs structures 
that have spacetime structures such as vibrations of collections of
particles or of fields. But the amalgamations of forms from the spacetime 
forms of the PAFs never produce, by any direct rational mathematical 
construction, any of the things like the experiences of color or pitch 
that were excluded from the outset from the physical world as it was 
conceptualized in classical physics.

You asked, above:
" And on the classical
conception, these spatiotemporal forms 'carry' all kinds of perceptual
reports. So I repeat, what makes macroscopic spatiotemporal sightings
different in principle (in the classical conception) from any other
perceptual reports? (Answer: nothing.)"

There seems to be here a basic disparity in our conceptions of what
the `classical conception' of nature is, and, in particular, on what,
*according to that conception*, is `carried' by the spaciotemporal forms.
I say that according to the classical conception these spacetime
forms `carry' only spacetime form: the spacetime forms are conceived
of, in the classical conceptualization, simply as idealizations of 
our experiences of the spacetime locations and shapes of objects.
Structures in space and time are what the classical physicist conceives
the world to be built out of, and he conceives his experiences of shapes
to be (with due allowance for small errors in perceptions) experiences of
features of this physical world of spacetime structures. But his 
experiencing of a `color' is not the experiencing of the vibratory
motion that in the classical conceptualization is the physical 
counterpart of the experienced color. Thus WITHIN THIS SPECIAL
CONCEPTUALIZATION OF NATURE there is a principled difference between
*physical* aspects of reality, which reside exclusively in spacetime form,
conceptualized as idealizations of our experiences of the spacetime-form
aspect of everyday experience, and the general phenomenal aspect of reality
that includes, for example, our experiences of color and
pitch, plus a vast amount more.

What I call "the classical conception of nature" may be different from
your notion of the meaning of this phrase. That is not what is important
here: that is just a matter of definition. What is important is this:
1. *If* one accepts what I call "the classical conception of nature" as the 
   way nature actually is then there is a principled distinction between
   the `physical' aspects of nature, which are built on idealizations of
   solely our experiences about the locations and spacetime shapes of 
   physical objects, and the general `phenomenal' aspects of nature, which
   include such other things as `color', `pitch', and a whole lot more. 
2. Certainly many educated people accept what I call "the classical
   conception of nature" as the scientific conception of nature without
   really recognizing that this is a very strong assumption, which they 
   should make explicit, because it leads them to `intuitions' about
   the physical and phenomenal aspects of nature whose origin they fail
   to be fully aware of, and whose possible failure they should 
   recognize. By explicilty recognizing the origin of their intuition
   they can formalize the basis of their prejudice, and thereby open 
   the way to moving beyond it.    

You go on to object to my analysis point by point. But your point is always
essentially the same, so let me pick one: 
I say: 

>one cannot *deduce* from the complete
>classical physical description of nature which `color' will be experienced
>when some observer looks at the leaf@@

You respond:
"Until the point marked @@, this is just wrong. Color is an objective
reflectance property, and the experience of color depends on it, the
lighting conditions and the immediate optical history of the subject (for
afterimages and the like.) Someone's experience of color is just as
(physically) predictable as their experience of anything else."

I am not talking about predicting! The issue that I am concerned with
is what is logically entailed, within the classical conceptualization, 
by the complete classical physical description of nature. There is certainly
no way of *deducing* the phenomenal feel of the color green from the vibratory
quality of a light beam. But there IS a way of deducing the leaf-shapedness 
of the boy gardener's experience of the leaf from the leaf-shapedness of 
the amalgamation of PAFs that, according to the complete classical physical 
description of nature, constitute the physical leaf. This deduction is 
possible because the theoretical conceptualization of the leaf as it is 
represented in the complete classical physical description of nature is, 
by virtue of it origin, exactly the same kind of thing as the 
boy-gardener's experience of the leaf: the former is constructed from  
idealizations of experiences like the latter. But in the case of greeness 
some *rule of translation* is needed because experiencing vibratory 
frequency is not an idealization of experiencing greenness.

This *rule of translation* may be establishable by empirical procedures, 
but it is not part of the classical conceptualization, and is not a 
necessary part of that conceptualization. On the other hand, the rule 
that allows the equating of leaf-shaped spacetime forms in the 
theoretical and empirical domains of experiences is a key part of the 
entire classical conception, because it is precisely this kind of
identification of forms that, within this classical conceptualization,  
is the primitive basis of the comparison between theory and experiment.

After the @@ I wrote:
@@; for the complete classical physical
>description is, by assumption, built exclusively out of properties like
>the properies we experience when we experience spacetime forms,
>not including properties like the properties we experience when we experience
>colors.

You said: 
"But after
@@, you shift your ground to the trivial (again.) If we simply DEFINE
'classical physics' as excluding properties like the properties we
experience when we experience colors, then of course these are not part of
'classical physics'. But that is a hollow victory indeed."

You miss my point! I am not shifting my ground: I am giving the reason for 
the truth of the preceding sentence. It is true that I `define' the classical
conceptualization, in the sense that I explain what it is. This particular
conceptualization is, I believe, the classical-physics conceptualization as 
it is understood by physicists, and by many other educated thinkers. 
So it deservers a name, and also to be `defined' or characterized for 
the purpose of this discussion. It is also true that according to this
definition, or characterization, the experience of colors is not part of 
`classical physics'. But his fact is not a victory. However, it is 
definitely something that ought to be recognized and appreciated by you.
For, many of the people against whom you argue do, I am sure, accept this
idea of nature, promulgated by classical physics, as a correct idea of the 
nature of physical reality, and within that conceptualization of physical
reality the principled distinction is true, as you have admitted. So what 
you are actually asking them to do is to abandon the orthodox (I think 
this is a fair terms here) idea of nature put forth by classical physics.
It would help communication if you would tell people that this is what
you want them to do.

You thought we had disposed of the *entailment* issue, but I think 
it is clear from the above that everything hangs on the fact 
that part of the classical-physics conceptualization is the notion that
the spacetime forms of macroscopic amalgamations of PAFs into spacetime 
structures that are large enough to be seen (or felt etc.) can be 
experienced by human beings as the spacetime forms that, according to the 
classical conceptualization, they actually are (apart from small errors 
in  perception). The analogous statement cannot be made for the quality 
of greenness, because the experience of greenness is not an experience of 
a property that, within the classical-physics conceptualization of nature, 
the leaf itself actually possesses (to some good approximation).

You say:
"But our experiences are NEVER `of the same kind' as the realities they
represent."

True! The sameness in kind is between the spacetime forms in our theoretical
conceptualization of nature and the spacetime forms in our empirical 
experiences of physical objects. The sameness in kind arises there from the
fact that the former are idealizations of the latter. But, according to
the classical conceptualization, our classical-physics image of nature
is a veridical picture of the physical reality itself, so the distinction
between the reality itself and our veridical picture of it is not a 
source of real difficulty.

You quote me:
>experience the greenness of a leaf. Phenomenally experienced greenness
>and phenomenally experienced spacetime form are DIFFERENT IN PRINCIPLE
>in the context of their connections to the concepts used by classical
>physicists to build their theoretical model of the physical world.

And then say:
"Well, I may simply have to defer to your historical suthority if this is
really true. But its not a claim Ive seen anywhere else, and it doesnt
square with almost everything Ive read about science before this
century,the apparent behavior and published claims of scientists from
Newton to Einstein, ar any other philosopher of science. Nowhere else have
I seen this claim that our spatiotemporal perceptions are somehow more
irreducibly physical than our other perceptions, or that physical models
can only be connected to observations of this particular very special kind."
 
Appeal to authority has no place this discussion. My argument is simply 
that classical physical theory is certainly built on particles and fields 
defined over spacetime, and that macroscopic spacetime structures
then arise naturally from the equations of motion, and hence that physical
objects can naturally acquire macroscopic spacetime form, but that this
natural physical process, governed by the laws of classical physics, though
it may entail vibratory motions of certain parts of the physical
system, for example a leaf, does not entail as a physical property of 
that system itself, in addition to its, say, leaf-shaped form, also a 
property or quality that is structurally essentially the same as the 
quality of greenness that a (normal) human observer who looks at the 
leaf (under normal conditions) will experience as a property of the leaf.
But the leaf will, according to  this classical conceptualization, itself 
have a physical property or quality, namely its leaf-shapedness, that is 
structurally essentially the same as the quality of leaf-shapedness
that a (normal) human observer who looks at the leaf (under normal 
conditions) will experience as a property of the leaf.  

The upshot here is that the experiences of greenness and of spacetime form 
do not enter in the same way into the classical-physics conceptualization
of physical reality. This is because physical reality, according to the 
classical-physics conceptualization of it, is represented in its entirety 
in terms of motions of particles and fields, which can generate macroscopic 
spacetime forms, including vibrations, that can be essentially equated 
to observers' experiences of spacetime forms. And this provides the basic 
primitive bridge between theory and experiment. But there is nothing in 
the classical-physics representation of, say, the leaf, that can be 
`equated' (to a good approximation) to the observers' experiences of 
the greenness of the leaf. What corresponds in the leaf to the 
observers' experiences of greenness is something quite different,
namely a vibration of the electromagnetic field. 

You quote me:
>--- because
>the conceptualization of the physical world provided by classical
>physics is erected on our notions of spacetime form extracted from certain
>sense experiences---we can empirically experience spacetime forms that
>can be taken to be identifiable with spacetime aspects of the
>complete classical physical description: moreover these spacetime forms
>can, because of this identification and the precepts of the theory, be
>considered to belong to both the physical and phenomenal worlds.

Then you respond:
"Yes to all this. But the key point, now, is that the physical form need not
be experienced as a "similar" phenomenological form, whatever that could
possibly mean. (Classical science tells us that a table is 'mostly' empty
space, yet it looks and feels solid. Which is right? An old schoolboy's
puzzle.) Physical vibrations cause neural firings which are experiences of
sound; em vibrations similarly give rise to experiences of color. And
certain large-scale assemblies reflect light in complex ways which we
experience as shapes, positions and movements of objects. But our
experiences of these 'forms' are no more similar IN KIND to the physical
'forms' than any other aspect of our phenomenology, and the complexity of
the story that must be told in order to link them to the PAFs of reality is
no less complex than that needed for colors, sounds, scents,... or, maybe,
emotions. In fact, there is lots of evidence that it is considerably MORE
complex."

Yes, the basic issue is  the connection of our brain activities 
to our experiences. I was responding to your attempt to say that
there was no principled difference because spacetime form and e.g., 
greenness were on a par as properties of the objects. But that was a 
diversion: the real issue is indeed what is going on in our brains.

But you say that the "neural firings... are experiences of sounds."  

According to classical physics, the firings of neurons are part of a 
physical world that is completely describable in terms of spacetime forms. 

It would seem that there is a problem in principle, here,
because if one makes the claim that, within the classical-physics 
conceptualization, some complex neuronal firing pattern IS the 
experience of hearing a certain sound then one can ask how this claim 
is to be proved true within the framework of classical physics.

We have seen how claims regarding the macrocscopic spacetime forms
of physical objects, such as leaves, can be proved within the framework 
provided by the classical conceptualization. And that sort of argument
can be carried over to the macroscopic spacetime properties of the
conglomeration of neurons etc. that comprise the brain. This gives
descriptions of `complex patterns of neuron firings', because these 
patterns ARE spacetime forms. 

But this kind of argument involves the spacetime structure of the 
object and the experience of that object by some observer who is 
observing that object through his senses.

The situation regarding the experienced sound is fundamentally 
different for two reasons: 

(1), the sound that IS the particular pattern of neural firings
is not an experience of a spacetime form. This characteristic of the 
experience was a crucial element in the former case: the capacity of 
human observers to `equate' the spacetime forms in their empirical
experiences of sensed objects to the spacetime form of the object as it is 
conceptualized in classical physics was the key tool in the former 
case.

(2), the relevant object in this case is not sensed by the relevant
subject through the normal senses, as it was in the former case of the 
leaf. 

Thus the method for linking the physical and phenomenal used for 
the cases of the ordinary physical sciences does not carry over to
this case: some new kind of `bridging principle' not needed in the normal
physical sciences is apparently needed.

I summarized:
>The bottom line is that because the classical model world is built
>exclusively upon idealizations and generalization of our sense experiences
>about spacetime structures it is only these special kinds of empirical
>experiences that can be conceived to be experiencings of the putative
>physical world itself. That constitutes a PRINCIPLED DIFFERENCE  between
>these kinds of experiences and, for example, a phenomenal experience
>of greenness. This difference biases  the whole picture in the way
>I have outlined above, and it prevents these latter sorts of empirical
>experiences from being entailed by the classical physical model in the
>way that empirical experiences of spacetime forms can.

You replied:
"At last I understand you; but I still don't agree. There is no difference
here, because these experiences - EVEN ON THE CLASSICAL STORY - are not
specially privileged. Your entire distinction is based not on a difference
between kinds of physics, but upon a spurious distinction based on an
outmoded view of perception. I suspect you have been misled by Bohr, who
seems to have been influenced by the behaviorist views of perception and
meaning that permeated the intellectual climate when he was writing.

So you have failed to convert me. But thanks again for being so persistent!!"
 
----------------------

After all this, I am not letting you off so easily, my friend!

Your claim that my whole view is not based on differences between kinds of
physics is at variance with the fact that my whole view is based specifically
upon the fact that the classical-physics conception that I discuss is based
upon spacetime forms, and the exclusion from the physical part of reality
of other kinds of possible realities. These spacetime forms are 
generalizations and idealizations of certain special aspects of the 
perceived world, but not of other aspects of the perceived world,
which could be included in other physical theories. 

It is true that our understanding of `perception' can undergo changes. 
You my wish to take a strict functionalist view of perception that gives no 
status at all to the phenomenal (conscious/experiental) aspect of the 
perceptual reality. However, in your other writings you do not seem to 
go to the extreme of denying outright the existence of phenomenal reality.
Rather you say there, and also here, that this reality IS some (functionally 
appropriate) activity in the brain.

Also, at least in this discussion, you are in effect claiming that it 
is OK---for these considerations---to accept the classical-physics 
conceptualization of the brain. This claim is, indeed, the point at issue.

There is, of course, a manifest *apparent* conflict between the two 
parts of your position: the classical-physics conceptualization claims 
that the brain is completely described in terms of spacetime forms, 
whereas your account of perception  admits the existence of a phenomenal
reality such as the experiencing of a sound, and this experiencing of
a sound is something that was *not included* in the classical-physics 
conceptualization of the physical part of nature, which includes the brain.

So there is the question of how something that IS, according to the 
classical-physics premise, a pattern of neuron firings, and a part of the 
classical-physics conceptualization of the physical part of nature, 
can BE an experiencing of a sound, which is among the things left out of 
the classical-physics conceptualization of the physical part of reality. 

According to the precepts of classical physics the pattern of firing IS 
the spacetime form of the corresponding PAFs, plus everything that is 
logically or mathematically entailed by these spacetime forms of the 
corresponding PAFs, but that's all.

So you need, in principle, to show, at least in principle, how the 
existence of the phenomemal experiencing could be entailed by the
spacetime form of the PAFs.

Your claim seems to be this will arise from a modern way of understanding
perception. 

It would not do to assert simply that the new understanding 
of perception asserts that the phenomenal reality IS the corresponding 
brain activity. For you have accepted here the classical-physics
conceptualization of the brain, and hence of the brain activity, and
that conceptualization must then be the starting point of, and a 
condition upon, any demonstration that this activity IS something 
described very differently. 

So I think you need to explain how a new understanding of perception 
could allow you to show how the classical-physics conceptualization of 
the brain activity can be shown to BE the phenomenal experiencing of,
for example the musical note `high C', without introducing any 
bridging principle that is not contained in the classical-physics 
conceptualization of nature.

Since you have said that my arguments against this does not depend upon  
"on a difference between kinds of physics" your demonstration
should be based on the classical-physics conceptualization that I have
described.

If you can truly succeed in this task you will have not only moved 
our discussion forward very significantly, but greatly illuminated the 
entire field.

Best wishes

Henry                                                   <hpstapp@lbl.gov>