Date: Mon, 10 Oct 2005 16:21:59 -0700 (PDT)
From: hpstapp@lbl.gov
Reply-To: hpstapp@lbl.gov
To:----
Subject: Townes Symposium: Session on Consciousness and Free Will.

Dear Colleagues,

I have just returned from the session on consciousness and free will,
and must say that it was not as inspiring as I had hoped it would be.
Clearly the non-physicists were laboring under a serious delusion as regards 
the issue of the causal closure of the physical (or physicalism) within quantum
theory. Yet the physicists made no effort to clarify this essential key point 
[which is not negated or undone by the very strong decoherence effects that 
surely mask effects of quantum superposition in the brain except at very short 
distances.]

From a philosophical perspective---and in particular in connection with
the issues of free will and causal closure of the physically described
aspects of nature---the key feature of quantum theory is poetically encapulated
in Bohr's oft-repeated assertion, echoed by Heisenberg, and by Pauli,
that  "in the great drama of existence we ourselves are both actors and
spectators."

Of course, as uninterpreted poetry this claim may sound unremarkable. It could 
without difficulty be interpreted within the conceptual framework of classical 
physics. But the reason it was so strongly emphasized by the founders is that 
it refers to a macroscopic aspect of quantum mechanics that is NOT compatible 
with the principles of classical mechanics, applied universally, and in 
particular to the dynamics of our own bodies and brains.

The point, simply put, is that the principles of orthodox quantum theory
involves not only the unitary deterministic evolution in accordance with
the Schroedinger equation, but also TWO DIFFERENT KINDS OF ABRUPT 
INTERVENTIONS, both of which involve a choice. The choice most commonly 
mentioned is what Dirac called "a choice on the part of nature". This
choice is a choice between different possible "outcomes of a measurement".
According to the principles of quantum mechanics this choice is "random":
it is constrained by a *statistical rule* that is specified by the theory.

But before this statistically controlled "choice on the part of nature"
can come into play there is a prior intervention, which is the choice of
which experiment is to be performed. It is this latter choice to which
the founders of quantum theory apply the adjective "free", or the adverb 
"freely" in "freely chosen". This deliberate use of the
word "free" in the phase "free choice on the part of the experimenter" stems 
from a profound basic difference between quantum mechanics and its classical 
predecessor, with respect to their causal structures.
This novel element of "freedom" in quantum mechanics, but denied by
classical mechanics, certainly ought to have been mentioned in any discussion 
of free will in the context of scientific theories.

Von Neumann put the logic structure of quantum theory into a very clear form. 
In his chapter on measurement theory, which makes explicit the connection, 
within quantum theory, between the mathematical structure and empirical data, 
he define TWO PROCESSES, Process 1 and Process 2. The latter, Process 2, is 
the unitary, deterministic evolution via the Schroedinger equation. The former,
Process 1, is an abrupt "intervention"
that disrupts the orderly and continuous evolution specified by Process 2.

A non-physicist might naturally think that this "Process 1" is the famous 
"collapse of the wave function" that is governed by the statistical rules of 
quantum theory that have been so often tested and so often
accurately confirmed. Thus we heard Bill Newsome say that the "quantum rules 
determine, in principle, everything that is happening in this room, at least 
statistically." Indeed, if Process 1 were the famous statistically controlled 
"collapse of the wave function" (or "reduction of the wave packet") then the 
common idea of non physicists---that quantum
theory is essentually a deterministic process with statistical fluctuations at 
the microlevel--- could be defended as being pretty close to the truth.

But Process 1 in NOT the statistically determined collapse of the wave 
function. The LATTER refers, in Dirac's words, to "Nature's choice of an 
outcome" of some experiment. For clarity, I call this statistical choice "on 
the part of nature" by the name "Process 3". But von Neumann's Process 1 is a 
very different kind of intervention, WHICH IS NOT GOVERNED BY ANY KNOWN LAW, 
STATISTICAL OR OTHERWISE!

Process 1 is a choice that, according to orthodox quantum theory, MUST PRECEDE 
the Process 3 choice of *outcome*. Process 1 is the  choice of which experiment
is performed. This choice is not specified by any known
law, statistical or otherwise, even when the body and brain of the
experimenter, and every other physically described aspect of nature---
i.e., all of the physical particles and fields in the universe and their 
constuents, as described within quantum theory, and all things constructed out 
of them in accordance with these laws---are included in the physical 
description. This huge causal lacuna, this fundamental causal
gap, is filled in actual practice, by treating this theoretically unspecified 
choice as "a free choice on the part of the experimenter."

The "freedom" of this choice is NOT determined to be an "illusion" by the
quantum laws in the way that it is determined to be an illusion by the laws of 
classical theory. The two theoretical situations are fundamentally different 
in this respect! According to classical physics, the choice on the part of the 
experimenter about what he or she will do---about how he or she will act---is 
in principle fixed by the "known" (although now known to be false) physical 
laws, and we have  causal closure of the physical. But this feature, Closure 
of Physical (CoP), does not carry over to quantum theory. Orthodox quantum 
theory, as it was created by the founders and was extended and rigorized by 
von Neumann, and as it is actually used and understood and empirically tested, 
DOES NOT ENTAIL CAUSAL CLOSURE OF THE PHYSICAL, EVEN MODULO STATISTICAL 
FACTORS. According to the orthodox principles there are interventions that 
are not controlled by any known laws, and thus CAN be, and in actual practice 
are treated as, determined by our conscious thoughts, feelings, and reasons.

This feature of quantum theory really should been brought out in this session, 
particularly because the philosophers and neuroscientists on the panel seemed 
not to appreciate that there is, with regard to this issue of the causal 
closure of the physical, a fundamental difference
in principle between the causal psycho-physical structure of quantum
mechanics and those intuitions and concepts that are in concordance
with the notion of causal closure of physical illustrated by classical 
mechanics.

It could be enormously important for future developments in
philosophy and neuroscience for workers in those areas to appreciate the fact 
that there is an INTRISIC CAUSAL GAP in the contemporary orthodox contemporary 
understanding of the BASIC PHYSICS OF THE MIND-BRAIN SYSTEM. It MIGHT be that 
this causal gap can be filled in a way that conforms to the principle of the 
causal closure of physically described aspects of nature.
But such a solution would render consciousness causally superfluous,
and our feeling that we enjoy "free will"---in the sense that our concepts, 
ideas, and reasons are themselves playing an irreducible role in determining 
our actions--- an "illusion". But the long-term
persisting lack of significant progress on the "Hard Problem", combined with 
the recognition of the failure of causal closure of the physical in 
contemporary basic physical theory suggests the possible benefit of a 
broadening of the theoretical playing field.

An extention to quantum theory of the principle of causal closure of the 
physical would be the most "boring" way of closing the presently existing 
causal gap. Hence this solution may be the correct one. But if, as Christof 
Koch and John Searle seem to believe, our conscious thoughts/feelings are  not 
"identical" to the associated brain process, but can be "influenced"


(changed from "caused", which suggests sufficiency, rather mere contributary)

by brain processes, then it is not necessarily complete nonsense to consider 
theories in which these thoughts ACT BACK upon the brain to fill the presently 
existing causal gap, and thereby
invalidate the principle of the causal closure of the physical.

These considerations really should have been brought out during a session that 
focussed, within the context of a quantum-physics
symposium, on the issues of consciousness and free will, and that moreover 
featured speakers that seemed blithely to accept the false idea that "science" 
entails causal closure of the physical. A mention of the fact that this 
principle fails in orthodox contemporary physics might have helped philosophers
and scientists to break through the  "conceptual barrier", created by 
uncritical allegiance to the NOW-UNSUPPORTED-by-physics
---and NEVER-SUPPORTED-by-intuition-and-common-sense---principle of the causal 
closure of the physical. This "freedom of choice" emphasized by the
founders of quantum theory, and formalized in von Neumann's Process 1,
could/should have been a central interesting point in this uninspirational 
session on quantum physics and free will.

At least it should have been mentioned!

Don't you agree?

Henry

P.S. I have attached a copy of my paper "Quantum interactive dualism:
an altermative to materiaism", which is to appear in the November issue
of J. Consc. Studies. It is an elaboration of the point of this letter.


P.P.S. Here is my imagined more satisfactory ending to the session.

After Tegmark says from the floor that he believes QM is not relevant
to consciousness and free will, and Zeilinger, on the panel, weakly disagrees, 
but can't say why, Charles Harper calls on Henry Stapp,
who expounds as follows:

Let me bolster Zeilinger's suggestion that QM might be relavant to the
issues of consciousness and free will. Tegmark has alluded to the fact
that decoherence effects effectively mask quantum-superposition effects
except at very short distances. But this merely shifts the problem to
the (reduced) density matrix, which should now represent "mixtures" of 
alternative possibilities. In the full state (density matrix) of the
universe the effects of the phases that drop out of the reduced density
matrix are still present. So insofar as one is interested in a conception
of "reality", as contrasted to a pragmatic FAPP (For All Practical Purposes) 
position, there is a question of how this mixture of alternative possibilities 
becomes just one of them. Tony Leggett referred
to this difficulty, and Cohen-Tannoudgi concurred. The problem is evaded by 
adopting a *pragmatic* stance as regards the proper role of science,
but it must be dealt with if one wants more that just a set of rules for
predicting future experiences from past ones.

But these practical QM rules do represent what basic science is able to say 
today.

These rules are based on THREE Process, not just two. One is the deterministic 
unitary evolution according to the Schroedinger equation. But, in addition, 
there are two processes that involve
choices. One of these is what Dirac calls "a choice on the part of
nature": it is a choice of one particular outcome of some experiment, and 
it is "random", in the sense that it is asserted to conform to a specified 
statistical rule. The second choice is what Heisenberg
calls "a choice on the part of the experienter", and what Bohr calls
a "free choice by the experimenter.

The word "free" is not an idle adjective here: it refers to the fact that this 
choice is not fixed or constrained by any known law, statistical or otherwise, 
and is treated, in the applications of the quantum rules, as determined by the 
conscious thoughts is the experimenter.

This means that contemporary orthodox QM has a causal gap that is filled
in actual scientific practice by our "free", as far as contemporary QM can say,
consciously made choices. This provides a rational opening for a conception of 
reality that conforms to orthodox contemporary physics and fills the causal gap
in a way concordant to the way it is filled in actual scientific practice.

Of course, there might be other, completely mechanical, ways that this gap 
could be filled, but any such solution would seem to leave open the question 
of why consciousnes exists at all, if everything is determined
by processes that do not rationally entail the existence of the feelings that 
we consciously experience.

In any case, orthodox contemporary QM has a causal gap that opens, in a 
natural way, the possibility for a conception of reality that brings in,
irreducibly, our "conscious free choices". It differs in this way very 
significantly both from classical mechanics and from an inaccurate conception 
of orthodox contemporary QM that includes only the deterministic unitary 
evolution and Dirac's statistically controlled choices on the part of nature, 
and leaves out the crucial part of orthodox
quantum theory that von Neumann called "Process 1"