Critique of Henry Stapp's "A Quantum Theory of Mind"
May 12, 2000......LBNL-45229
A Quantum Theory of Mind.
Henry P. Stapp
Lawrence Berkeley National Laboratory
University of California
Berkeley, California 94720
A theory of consciousness is erected on von Neumann's formulation of quantum
theory. More specifically, a theory of attention and mental effort is
developed. This presentation is aimed at psychologists: it assumes no
familiarity with quantum theory. The theory is highly structured, compared
to theories based on classical concepts, because it rests heavily on
restrictive quantum conditions on the form of the interaction between mind
and brain. These restrictions invest the theory with significant explanatory
power. Supporting empirical evidence comes both from the general
observations of William James and from recent experimental findings
pertaining to attention and mental effort.
1. Introduction.
Classical physical theory provides an unsatisfactory foundation for a theory
of consciousness. The precepts of classical physics require all brain
activity to be in principle completely determined by bottom-up local atomic
processes alone, with the experiential events that form a person's stream of
consciousness making no difference at all either to his bodily behaviour or
to what is happening in his brain. This has two unsatisfactory consequences.
It means that there is no reason for the incredibly elaborate, complex, and
sensitive system of human consciousness ever to have evolved, and hence no
way to understand the causes of its development. And it means that conscious
experiences must be added to the theory ad hoc, simply because we know that
they exist, rather than because they are logically necessary parts of a
unified dynamical theory of the natural world. Consequently, the explanatory
power of any theory of consciousness based on classical physical theory is
inherently limited by this fact that in classical theory consciousness is a
free-floating supernumerary having no fixed logical connections to the
physical world.
[Peter]
This is quite extraordinary, because making "consciousness a free-floating
supernumerary" is at first blush *exactly* what the von Neumann/Wigner
theory achieves, in contradistinction to the Copenhagen interpretation. It
ostensibly accomplishes this by making almost everything physical and then
making consciousness but an extension of the actual observer, a 4 to I
(actually observed system), II (measuring instrument), and III (actual
observer), whose only function is to register the final result.
[Henry]
The situation is completely reversed if quantum theory is used. Within the
quantum framework a rational approach leads naturally to theory in which
mind enters into brain process as an integral and logically necessary
component of the basic dynamics. Thus the fundamental physical principles
impose stringent conditions both on the way consciousness arises from brain
action, and on the way it acts back on the brain. The theory of attention
and mental effort that emerges from this tight knit approach has impressive
explanatory power. It explains both the general features of attention and
efficacious mental effort described by William James at the end of the
nineteenth century, as well as certain empirical findings that have remained
mysterious and unexplained since that time, and also many hitherto
unexplained features uncovered by recent empirical work.
It is well known that the founders of quantum theory introduced the observer
and his observations into physical theory. This innovation constituted a
sharp break from the ideas of classical physical theory, which placed the
conscious experiences of human observers outside the part of nature dealt
with by physical theory. But according to quantum philosophy, as articulated
by Niels Bohr: "In our description of nature the purpose is not to disclose
the real essence of phenomena but only to track down as far as possible
relations between the multifold aspects of our experience."[1] In the words
of Heisenberg: "The conception of objective reality of the elementary
particles has evaporated not into the cloud of some new reality concept but
into the transparent clarity of a mathematics that represents no longer the
behaviour of the elementary particles but rather our knowledge of this
behaviour."[2] Human experience and knowledge thus became identified as
precisely the thing that basic physical theory is about. Moreover, the human
experimenter plays a key dynamical role: a human intelligence standing
outside the physical system, as it is represented by the mathematical
machinery of quantum theory, chooses which aspect of nature will be probed.
[Peter]
There cannot be an observer without an observed, *even if* the relation of
observer to observed is essentially what is observed. In the Copenhagen
interpretation it is not even that direct, because it is assumed that there
is a classical pole of reality (the reality of the observer), which I call
the meta-physical, and a quantum pole of reality, which is the physical. So
there is alot of structure, phenomenal and mental for instance, mediating
between the observer and what is observed. Bohr also muddied the water by
conflating the noumenon (at the physical pole of reality) with the
phenomenon (at the phenomenal level of reality). The phenomenal level of
reality is the objective pole within the essentially classical portion of
reality. I may as well state it straight out that I see a necessity to
demarcate seven levels of reality (these constitute the ontological system
of worlds): physical, emotional, mental, etheric, phenomenal, causal, and
archetypal or meta-physical (classical). The lower three levels correspond
to von Neumann's I, the etheric to his II, and the upper three levels to his
III. The archetypal and phenomenal as well as the mental and physical,
constitute subject-object polarities, while archetypal and physical
constitute the overarching subject-object polarity. Von Neumann's I, II,
and III, themselves, constitute the direct connection, across the oroboric
abyss, between the physical and the meta-physical, whereby the physical is
bootstrapped into existence.
Heisenberg's statement (above) if taken as a boast is not good. I take it
as a lament. There is an implicit ignorance in the statement concerning
both reality and knowledge, from an ontological or philosophical point of
view. I have indicated what I think the basic structure of reality is, and
knowledge also has a philosophically defined context. Kant defined the
context of understanding in vertical relation to sensibility and Jewish
mysticism has defined understanding in horizontal relation to wisdom and
understanding. With these definitions, there is nothing to prevent us from
understanding knowledge as an actually observed system, von Neumann's I.
So, the dualism is already mitigated and we are viewing the quantum reality
from within the quantum reality. This is a portending of Whitehead's
treatment of essentially subjective quantum systems, which he claims are the
only actual entities in existence. The brain with its networks, neurons,
and junctions can also be regarded as an actually observed system in the
extended metaphysical sense, *within the Copenhagen framework.*
[Henry]
In Bohr's words: "The freedom of experimentation, presupposed in classical
physics, is of course retained and corresponds to the free choice of
experimental arrangements for which the mathematical structure of the
quantum mechanical formalism offers the appropriate latitude."[3]
[Peter]
This is no trivial statement. It shows that Newtonian physics is regarded
as embedded in Cartesian philosophy, where thought is regarded as
independent of extension. Von Neumann's abstract "ego" must also be
understood in this manner, as a subjective pole in relation to the object
achieved by classical bottom-up causation. That is his inward glance,
within the bi-polar subject. His outward glance is toward the phenomenal
object of the quantum explicate order, fulfilling his role as an actual
observer in the quantum sense, von Neumann's III. Moreover, as Bohr et al.
emphasized, quantum theory was merely an extension of classical physics into
the atomic domain. What this means is that the inward glance is prior to
the outward glance. The inward glance actually leads to transcendence of
classical objectivity, proscribed by extension and thought, and a
realization on the part of the abstract "ego" or subject of the *essence* of
thought, which leads beyond the physical sub-world of the seventh or
meta-physical world to its mental sub-world, which is the quantum implicate
order. It is this quantum implicate order that unfolds to become the
quantum explicate order, comprised of the seven levels or worlds enumerated
earlier. Whatever is in the explicate order is also in the implicate order,
enfolded, and whatever is in the implicate order is also in the explicate
order, unfolded. This possibility of transcendence on the part of the
abstract "ego," which *is* in a sense the whole brain, was indicated by
Descartes in his doctrine that the Pineal Gland was the doorway to
transcendence of the the Newtonian laws.
So, in a profound sense, everything is subjective from the quantum point of
view. However, it is the first or physical world that contains the noumenal
pole of reality, even within the mind of the observer, which is the quantum
implicate order. The unfolding process occurs so that the mind can come to
know the noumenal pole of reality within it, to unwrap it, so to speak.
Lest this seem outrageous, Henry Stapp himself has been the first to
acknowledge that quantum theory is thought-like. The only problem is that
he has lost his moorings in the well defined context established by
classical Cartesian philosophy, which he mistakenly rejects. It is only
Newtonian physics that the founders rejected, not Cartesian philosophy,
which is big enough to include quantum physics. In fact, Cartesian
philosophy mandates quantum physics, which constitutes its fulfillment.
Although the attributes of extension and thought are meta-physical and
classical, as attributes are in quantum theory also, the thinking thing and
the the extended thing are necessarily quantum in nature, there being no
real things in classical physics (since there are no real boundaries between
things) and only one thing, namely all of nature.
[Henry]
This Copenhagen approach is ideally adapted to the practical applications of
quantum theory to laboratory experiments. It enables quantum physicists to
avoid getting entangled in metaphysical issues that are, for all practical
purposes, irrelevant to these important applications. This Copenhagen
quantum theory rests on the idea of dividing nature into two parts: "an
observed system", which is described by the mathematical machinery of
quantum theory, and "an observing system", which includes the human
observers and their measuring devices. The latter are described in everyday
language, refined by the concepts of classical physical theory, without,
however, suggesting that classical physical theory really holds exactly for
this part of the world: ordinary language is simply the language that we
humans do in fact use to communicate to others what we have done, in setting
up the experiments, and what we have learned from our observations.
[Peter]
In this statement, Henry has in fact made all the deeper considerations he
has championed epiphenomenal, or else he has abandoned the scientific
method. Since striking successes in quantum theory have only come in a few
areas, notably quantum electrodynamics, it seems very premature to suggest
that the metaphysical issues will not bear on laboratory results. Again he
contradicts his presumed idealism by suggesting that the laws that govern
human observers do not govern a genuine "part of the world." This is to
grant substance to that which he has already emphasized is without
substance, namely an independent material substratum of reality. If, on the
other hand, everything is really constituted by experience, then how can the
laws which govern that experience not govern that "part of the world"?
[Henry]
The practical virtues of the Copenhagen approach stem directly from this
division of the dynamically unified world into these two differently
described parts. Though useful in practice, this tearing asunder of the
unified physical world is, from the standpoint of principle, a disaster.
However, this problem at the level of principle was solved by John von
Neumann, who showed that the predictions of Copenhagen quantum theory could
be obtained in principle by treating the entire physical world, including
the bodies and brains of the human observers, in the mathematical language
of quantum theory, and allowing the experiences of each observer to interact
dynamically, according to quantum precepts, with the brain of that observer.
This gives a highly constrained theory that is, at the same time, both a
logically coherent way of formulating quantum theory and also a suitable
physical basis for a theory of consciousness.
[Peter]
This tearing apart of the naive conception of the "unified physical world"
is the very essence of the quantum revolution, to my mind. Jaya Nrsinhadev! It is not a disaster at all, except to those still subtly attached to
naive realism. Rather, it is the opening of the metaphysical door to a
deeper conception of reality, including physical reality. What might be
somewhat of a disaster is the vagueness with which the founders drew the
lines of demarcation between the metaphysical hypostases, but that can be
chalked up to fear of peer pressure within the physics community, which even
now condemns anyone for espousing sound metaphysical doctrine, i.e., genuine
idealism.
What von Neumann did is very subtle. He did not simply revert to a "unified
physical world," as Henry maintains. He recognized, along with Bohr et al.,
the profoundly metaphysical character of the new worldview, and he achieved
the unified treatment only by an application of the principle of the
psycho-physical parallelism, which he defines as follows: "that it must be
possible so to describe the extra-physical process of the subjective
perception as if it were in reality in the physical world -- i.e., to assign
to its parts equivalent physical processes in the objective environment, *in
ordinary space.*" (p. 419, "Mathematical Foundations of Quantum Mechanics")
Definition: S (System), M (Measuring Apparatus), and O (Observer) are I,
II, and III after (1) expansion into ontological correlates [as described
above] and (2) reduction to near physical elements by the principle of the
psycho-physical parallelism. Then we can indeed consider the wave function
for the composite system S + M + O as the representation of the total state
vector *in ordinary space.*
In the psycho-physical representation of the observer, however, an
interesting transposition takes place. If it is possible to conceive of the
observer-observed (the observed here is a relative projection of the
observer) as psycho-physical, then it is possible to conceive of the other
psycho-physical elements, i.e, the system and the measuring apparatus, as
observers, or observer-observed pairs. This is already indicated by the
fact that the system is a subject-superject.
The basic structure of quantum mechanics is that the physical quantum object
(von Neumann's I) must be conceived of in terms of eigenvectors of an
operator representing a classical (meta-physical) observable (von Neumann's
III). But if von Neumann's I can also be regarded as an observer (through
the principle of the psycho-physical parallelism) then we can stipulate that
the phenomenal object which III sees must be conceived of in terms of the
eigenvectors of an operator representing I as an observer. This sets up the
correct notion of relative (eigen)states. So, it already becomes clear that
S, M, and O tend to represent states, while I, II and III tend to represent
operators.
But if von Neumann applied the type of physical reductionism implied by the
principle of the psycho-physical parallelism to his process 2, or unitary
development according to the Schrodinger Equation, he also applied a form of
the phenomenological reduction of Descartes and Husserl to his process 1,
which involves the reduction postulate and the interaction with the actual
experience of the observer in his absolute or transcendental aspect. In
other words, he ultimately conceives of I, II, and III in the context of a
new nonontological or epistemological system of worlds that connects the
ontological framework of Copenhagen with the phenomenological realm of
Descartes and Husserl.
This interpretation is indicated by two aspects of the mathematical
treatment in "Mathematical Foundations of Quantum Mechanics." On page 425
(Sec. VI.2) von Neumann says: "We have thus established the rules of
correspondence for the statistical operators of I, II, I + II, i.e.,
U, U, U. *They prove to be essentially different from those
which control the correspondence between the operators A, A, A
of physical quantities.*" Von Neumann's words here are a bit confusing,
since "the statistical operators of I, II, I + II" should be thought of in
terms of S, M, S + M (which emphasizes even more clearly the distinction
which von Neumann himself is making) while "physical quantities" in I are
*phenomenal geometries* in III. To make them all consistently physical (NOT
in a "unified physical" sense) and self-contained is the goal von Neumann
sets for himself in his later work, which was never completed.
On page 441 (Sec. VI.3) von Neumann says: "We shall indeed show that such a
determination of Delta [time development operator of combined S + M which
will correlate the eigenvectors of I and II] is indeed possible. In this
case only the principle is of importance to us, i.e., the existence of any
such Delta. *The further question, whether the Delta corresponding to
simple and plausible measuring arrangements also have this property shall
not concern us. Indeed, we saw that our requirements coincide with a
plausible intuitive criterion of the measurement character in an
intervention. Furthermore, the arrangements in question are to possess the
characteristics of the measurement. Hence quantum mechanics would be in
blatant contradiction with experience, if these Delta did not satisfy the
requirement in question (at least approximately). Therefore, in the
following, only an abstract Delta, which satisfies our conditions exactly,
shall be given.*" Although von Neumann's reasoning here seems confused and
less than rigorous (since it is the eigenvectors of I and III that should be
correlated), it is clear that he is invoking a Kantian argument to the
effect that there is an ideal structure that any measurement must conform to
in order to constitute a measurement. This ideal structure involves
consciousness and the structure of experience within consciousness.
[Henry]
There is, however, one effect, well known to physicists, that seems at first
to block any important contribution of quantum effects to the efficacy of
consciousness. This effect, called environmental decoherence, is the strong
tendency of a warm wet system, such as a human brain, to be effectively
decomposed by interaction with its environment into a statistical mixture of
quasi-classical states. This decomposition would appear, superficially, to
eradicate all macroscopic quantum effects that might contribute to the
efficacy of mental effort in the control of brain activity [4].
Consideration of this decoherence effect played, in fact, a crucial role in
the development of the theory of consciousness described here. It forced the
theory to rely, in order to achieve strong effects of mental effort upon
behaviour, on the Quantum Zeno Effect. This is a well-known and well-studied
quantum effect that is not weakened by environmental decoherence, and it is
the basis of the theory of efficacious mental effort described here. The
essential point, which will be explained in detail, is that focus of
attention is maintained by mental effort via the physical mechanism of the
Quantum Zeno Effect, and this connection explains many empirical features of
the mind-brain connection.
This article is aimed at mainly psychologists. No knowledge of physics is
assumed. Indeed, it may be beneficial not to know any physics, because
quantum theory alters or reinterprets everything that classical physical
theory says. Hence understanding classical physical physics creates
prejudices that have to be overcome. I intend here to be both precise enough
to satisfy quantum physicists yet clear and simple enough to reach readers
with no knowledge of either classical or quantum physics. Once I have
introduced from scratch a few simple ideas, I shall actually derive the
Quantum Zeno Effect, and show how it works to make mental effort causally
efficacious in the control of physical processes in a human brain. Then I
shall compare the resulting properties to both to the observations of
William James, and empirical results of the last half century, with emphasis
on results about attention and effort obtained in the last two decades.
2. The Form of the Interaction Between Mind and Brain.
This work is based on objectively interpreted von Neumann/Wigner quantum
theory. I have argued elsewhere [5] that the evolving state S(t) of von
Neumann/Wigner quantum theory can be construed to be our theoretical
representation of an objectively existing and evolving informational
structure that can properly be called "physical reality".
[Peter]
Construing S(t) as "an objectively existing and evolving informational
structure that can properly be called 'physical reality'" is OK so long as
you do not imply by "objectively existing" an *independent* reality. If you
do, then indeed, you reinstate the very bottom-up causation that makes the
consciousness of the actual observer an epiphenomenal supernumerary, *even
and especially within the von Neumann/Wigner form of quantum mechanics.*
But in von Neumann's own approach, clarified by me, the total state of S + M
or S + M + O is NOT an independent reality. It is obtained only by the
principle of the psycho-physical parallelism and contains within it the
dependence on the "extra-physical" reality of which it is an abstraction.
[Henry]
von Neumann/Wigner quantum theory is essentially a theory of the interaction
between this objective physical reality and subjective human experiences.
[Peter]
True, but the way in which this interaction transpires is philosophically
complex. On the one hand, "extra-physical" ontological dimensions are
reduced to the psycho-physical and then the physical, but on the other hand,
the ontological is reversed by nonontological or epistemological
considerations that interface and hence interact with the phenomenological.
This is a form of the phenomenological reduction of Descartes and Husserl.
[Henry]
The earlier Copenhagen version was essentially subjective, being,
fundamentally, merely a set of rules that allow scientists to make
predictions pertaining to connections between possible human experiences.
[Peter]
I strongly disagree with the word "merely" in this context.
[Henry]
It renounced the effort to understand the reality lying behind these rules.
[Peter]
It renounced only the notions of *naive* reality underlying the rules of
human experience. By renouncing naive reality, it opened the door to the
genuinely deep metaphysical reality, even as William James foretold in the
introduction to his "Principles of Psychology."
[Henry]
The immediate objective of the von Neumann theory was to show how these
empirically validated Copenhagen predictions about connections between human
experiences can be deduced from a rationally coherent conception of an
objectively existing physical reality that interacts in specified ways with
the subjective elements described in the Copenhagen formulation. Thus von
Neumann and Wigner supplied, first, a putative description of the underlying
physical reality that the Copenhagen approach tries to ignore, and, second,
the form of the interaction between this objective physical reality and the
experiential realities that are the basis of the Copenhagen approach.
[Peter]
True, but there is a fundamental application of complementarity in these two
stages of the von Neumann/Wigner approach. Bohr himself, after his 1936
meeting with von Neumann in Copenhagen, was well aware of this development.
He spoke thereafter of the need for a deeper application of complementarity
that would take into account the underlying quantum nature of the measuring
devices and lead to the "deeper lying laws of nature." BUT HE EMPHASIZED
THAT THIS WOULD REQUIRE AN EVEN DEEPER RENUNCIATION OF THE *NAIVE* NOTIONS
OF AN OBJECTIVE INDEPENDENT REALITY! In fact, on page 420 of "Mathematical
Foundations of Quantum Mechanics," von Neumann attributes the principle of
the psycho-physical parallelism to Bohr. Bohr most certainly understood it
the way I am suggesting - as one of a dual set of principles related through
the overarching principle of complementarity. The other dual principle was
of course the phenomenological reduction of Descartes and Husserl.
Email: Peter Mutnick
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