MENTAL FORCE IN QUANTUM PHYSICS: The Status of Conscious Thoughts in Science, and Their Possible Causal Efficacy in Mind-Brain Dynamics. 1. A Sampling of Disparate Views of Philosophers on Mind-Brain Connection. Daniel Dennett: Normal intuition about consciousness is ``like a benign user illusion" or ``a metaphorical by-product of the way our brains do their approximating work." Eliminative Materialists (Churchland): Consciousness does not exist: neurons do. Identity Theorists: A conscious thought is identical to a pattern of neuron firings in a brain. Epiphenomenal Dualists: A conscious experience is not identical to a physical brain activity: it is caused by the brain, but has no effect on the brain. 2. My three claims are: A. The connection between consciousness and the brain is primarily a physics problem: The disparateness and counterintuitiveness of philosophical opinions on the subject arise from their being based on a conception of the brain that is fundamentally false. B. Physical theory has now advanced from an earlier ontological form that left consciousness out, to a pragmatic-epistemological stance that: (a) is built directly upon our conscious experiences, and (b) is compatible with our normal intuitions about consciousness. C. Within this pragmatic-epistemological framework a person's conscious volitions, per se, can causally influence brain activity. 3. According to the Pragmatic-Epistemological View, science is concerned with what we can "know", and how we can "use" our knowledge to form expectations about our future experiences, under the various possible conditions that we may choose to initiate. 4. The classical physics of Newton was ontological: It was about a physical reality conceived to BE a collection of trajectories of tiny particles moving through space-time. The theory did not explain: How we could ``know" anything about these trajectories, or ``do" anything about them. Classical physics is, in this sense, not a complete science: *It is compatible with the nonexistence of our knowledge, *It fails to explain how we acquire our knowledge, and *It makes it theoretically impossible for us to use our knowledge. 5. Physicists have tried hard, but failed, to reconcile their empirical findings with the classical notion that the world was made up of tiny particles moving on well defined trajectories under the influence of [local] forces exerted on them by their neighbors. Failing this, they have advanced from a provably false ontology to a pragmatic-epistemological science that works. 6. Dennett described the recurring idea pushed him to his counter-intuitive conclusions: ``a brain was always going to do what it was caused to do by local mechanical circumstances". ``Local mechanical'' reveals the tacit classical-physics basis, or bias. 7. Dennett says, of his opinions about consciousness,: `` If one's allegiance is to the physical sciences and the third-person point of view then this disposition of the issues can seem ...inevitable." But orthodox quantum mechanics: * rests on ``subjective" conscious experiences. * is ``objective" in the sense of the *intersubjective agreement* of the shared aspects of our knowledge. * does not cling to the ``third-person point of view'' of classical physical theory. The classical basis of Dennett's thinking is again evident. 8. The basic idea of Copenhagen interpretation of Bohr, Heisenberg, Dirac, Pauli, Born, et. al. is that each new human experiential knowing that pertains to a quantum mechanically described system causes a reduction (or collapse) of the quantum state of that system to a new state that is compatible with that new knowing. However, according to that Copenhagen Interpretation, the brains of the knowers should not be included in the quantum-mechanically described system. 9. Von Neumann and Wigner demur: they include our brains because: (1) Our brains are made of atoms, and hence there is no natural way to keep them out; and (2) Our conscious experiences are clearly associated with our brains. Because our brains are now included, along with our minds, the vN/W formulation provides a coherent possible framework for understanding the mind-brain interaction. 10. My technical claim is: Within the vN/W formulation a volitional experience, which is a real element of the dynamical theory, can causally effect brain activity: mind and matter can interact. 11. The details are technical: I shall describe the key ideas. 12. The basic premise of pragmatic-epistemological [Copenhagen or vN/W] quantum theory is that the quantum state represents "our knowledge", and the occurrence of an "experiential increment in knowledge" reduces the quantum state to the part of it that is compatible with this increment of knowledge. [Historical background--- 1927 Solvay conference: (Hendry, 1984) "Dirac, in discussion, insisted on the restriction of the theory's application to our knowledge of a system, and on its lack of ontological content." Hendry summarized the concordance by saying: "On this interpretation it was agreed that, as Dirac explained, the wave function represented our knowledge of the system, and the reduced wave packets our more precise knowledge after measurement." Heisenberg (1958a): "The conception of objective reality of the elementary particles has thus evaporated not into the cloud of some obscure new reality concept but into the transparent clarity of a mathematics that represents no longer the behavior of particles but rather our knowledge of this behavior." Heisenberg (1958b): "...the act of registration of the result in the mind of the observer. The discontinuous change in the probability function... takes place with the act of registration, because it is the discontinuous change in our knowledge in the instant of registration that has its image in the discontinuous change of the probability function." Heisenberg (1958b:) "When old adage `Natura non facit saltus' is used as a basis of a criticism of quantum theory, we can reply that certainly our knowledge can change suddenly, and that this fact justifies the use of the term `quantum jump'. " Wigner (1961): "the laws of quantum mechanics cannot be formulated...without recourse to the concept of consciousness." Bohr (1934): "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." [For references and elaboration see--- http://www-physics.lbl.gov/~stapp/ stappfiles.html][New Book] Conclusion: In orthodox quantum theory each experiential increment of knowledge is represented in the mathematical formalism by a reduction of the quantum state to one compatible with the new knowledge. It is this feature of quantum theory that leads some physicists, such as Penrose and myself, to believe that it is to quantum theory, not classical physical theory, that one should turn for the scientific foundation of an adequate theory of consciousness. 13. A Key Technical Point: The Two Kinds of Choices! Heisenberg Choice and Dirac Choice `The Observer's Choice' and `Nature's Choice'. Niels Bohr, describing Solvay 1927, says: "An interesting discussion also arose about how to speak of the appearance of phenomena for which only predictions of statistical character can be made. The question was whether, as to the occurrence of individual effects, we should adopt a terminology proposed by Dirac, that we were concerned with a choice on the part of "nature" or, as proposed by Heisenberg, we should say that we have to do with a choice on the part of the "observer" constructing the measuring instruments and reading their recording." The key point. To make quantum dynamics work *two* choices must be made: First, the "observer" must pose a specific question that can be answered `Yes' or `No', and whose `Yes' answer corresponds to a recognizable possible experience. Then "nature" will answer `Yes' or `No'! That *previously selected* recognizable possible experience will either appear, or it won't appear. Statistical rules govern nature's choice. But *no known basic rules* govern the "observer's choice" of which question will be asked: of which aspect of nature will be probed. 14. The basic idea of the non-orthodox interpretations of quantum theory is to use this basic looseness of the theory to get the observer *out* of the theory. I shall use it to glue him more securely *in*.. 15. Within the vN/W framework this theoretical looseness, pertaining to the choice of the question, allows our conscious thoughts to play a powerful causal role. 16. But how can one's mere choices of which questions to ask exert a causal influence on the activities of his brain? 17. Example: Quantum Zeno Effect. According to the rules of quantum theory, a rapid repeated posings of the same question Q, when answer initially is YES, tends to *freeze* the answer at YES. This effect OVERRIDES to the normal forces and inertial motions. The dynamical laws force the system to repeatedly jump back to where it originally was. 18. The key question then becomes: How is the question chosen? 19. To stay within science we impose the QUANTUM IDENTITY THESIS: The mind-brain system contains nothing outside the vN/W quantum description of it. 20. Proposed quantum model of mind-brain dynamics. 1) High-level brain processing is built around the body-world schema, the brains representation of the body and the world around it. An extended body-world schema is a sequence is body-world schemas, representing an evolving image of body-world that ``projects" slightly into the future: ``My arm will presently rise". 2) Each experience (of the kind under consideration) is experienced as a increment in knowledge pertaining the body and world, and it actualizes the extended BW schema that is the "neural correlate" of that conscious experience. 3) The evolution of the actualized state can bring into being, via mechanical workings of the brain that can be well treated by classical approximations, future possible experiences in which a "projected" feature of earlier experiences now becomes "current": "My arm is now rising". 4) However, quantum uncertainties will cause a diffusion of the likely possibilities around the intended possibility. 5) Quantum dynamics now demands that some specific question with an experiential answer be posed, but it does not specify how this particular question is chosen. 6) The quantum identity thesis permits no selection to come from outside the full quantum system. So more internal rules are needed. 7) Proposed Rule: The question asked at the time when a formerly projected image should now be current is ``Is the intended image now occurring?''. [Thus the current experiential question is specified by the earlier experience.] 8) This resolution can lead to a repititous asking of the same question, hence to a Quantum-Zeno-Type Mental Force. 21. Partial Independence of Mental Process: The causal process involves a sequence of experiential events, in which experiential aspects of earlier events feed directly into the (Heisenberg choices associated with) later events. Thus there is *a line of causal connection that works directly through the experiential realm*. But there is a close linkage to the brain, because each experiential events *causes* the actualization of its neural correlate, and this actualization feeds into the determination of the probabilities associated with the successor experiential events. 22. Free Will. In this model the flow of experiential events is not determined exclusively the Schroedinger law that governs the evolution of the physical state, nor even by the combination of that law with the famous element of quantum randomness. There are added rules that deal directly with the experiential aspects themselves, and that resolve the looseness pertaining to the Heisenberg choice. Quantum theory is richer in logical possibilities than classical physical theory. 23. The Origin of Nature's Dynamical Rules; I suggest that the dynamical rules may emerge by a process of natural selection, based on a tendency of certain kinds of self-replicating events to produce enduring societies of such events. The concept of the self-replicating mental event is the basis of the Quantum-Zeno-type mental force.