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.
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.
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.
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." 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." 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.
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.*
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."
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.
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.
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"?
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.
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.
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 .
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  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".
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.
von Neumann/Wigner quantum theory is essentially a theory of the interaction between this objective physical reality and subjective human experiences.
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.
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.
I strongly disagree with the word "merely" in this context.
It renounced the effort to understand the reality lying behind these rules.
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."
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.
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.