From chriswilson2000@earthlink.net Fri Jul 13 08:49:39 2001 Date: Wed, 11 Jul 2001 16:04:57 -0700 To: hpstapp@lbl.gov Subject: Re: Essential Agreement with Searle? (fwd) May I just say that I think these most recent exchanges with Searle et al., together with the Ann Arbor paper are admirably clear and convincing. Regards, Chris From stapp@thsrv.lbl.gov Fri Jul 13 08:51:04 2001 Date: Tue, 10 Jul 2001 19:15:41 -0700 (PDT) To: John R. Searle Subject: Re: your mail On Tue, 10 Jul 2001, John R. Searle wrote: > Dear Henry, > > I was travelling a lot in Europe when all the various email > correspondence took place. I'm afraid I am rather out of the > discussion, but there is one point that is important that I want > to be clear about. > > As far as I understand your position, you have no explanation > at all for the very existence of consciousness. It is taken > to be an absolute primitive in your system, not to be > explained by neuronal or other sorts of physical processes. > If I am right in interpreting you in this way, then it seems > to me you part company not only with neurobiology but with > pretty much all of contemporary science. On my view > consciousness is a system or higher level feature of the > brain entirely caused by neuronal processes and realized > in the neuronal system. Am I right in thinking that you reject > this view altogether? That is, am I right in thinking > > 1. You do not think that consciousness is caused by brain > processes, and > > 2. You do not think there is any causal explanation for the > very existence of consciousness at all. > > Anyway, once again many thanks for participating in my > seminar. I look forward to our continued exchange of > ideas. > Yours ever, > John Searle > Dear John, Your questions are hard-edged and directly to the (or `a') point, as usual. I shall also be blunt: 1. I think consciousness is caused brain processes, at least in part. 2. I think there is some causal explanation for the existence of consciousness. Let me elaborate, on the basis of my Ann Arbor talk. I believe that most neurobiologists and most of contemporary science agree the quantum theory is basic and should be the foundation of neuroscience, in principle. Indeed, a lot of brain process is chemical, for which quantum theory is needed in principle. But there are big differences in opinion as to how necessary it is in practice to use QT. Still, most scientists recognize that QT ought to be used IN PRINCIPLE. Indeed, all of the validated predictions of classical physical theory can be derived from QT, so there is no rational scientific reason not to accept QT as the best contemporary foundation for neuroscience and the quest for a scientific understanding of consciousness. The next the question is: What is the structure of a QT of the brain? The Copenhagen interpretation (QT is merely a set of rules that allow scientists to compute predictions about connections between their observations) is not applicable because biological systems are explicitly excluded. All other interpretation begin with von Neumann's approach of bringing all particles and EM and Grav fields, and hence everything constructed out of these spacio-temporal structures, into the system described by the quantum mathematics. There is a well defined way to do this, and it is awkward and inconsistent to leave some of these particles out. But there are two processes that are not specified by the the quantum laws and principles as they are currently understood: What chooses the particular "answer/outcome" to the questions that are posed by systems that stand outside the system described by the quantum mathematics? What chooses the particular question that is posed by that outside system? The point is that the mathematics is structured around these posed questions, and the answers to them. Some physicists prefer to evade these question by going to the many-worlds/minds scenario, where every possible thing happens. I believe that it can be ruled out for technical reasons, but won't go into that here. I believe most physicist reject the Bohm and Ghirardi-Rimini-Weber ontologies. Von Neumann's QT is I believe the prime contender for a quantum theory of the brain, and I accept it as the best and most orthodox basis for a QT of brain dynamics. Now in vN QT the brain certainly "causes" consciousness: The quantum state of the brain evolves in accordance with the laws and prinples of QT, and evolves necessarily into a superposition of distinguishable states that are initiating different possible classically describable courses of action: the Heisenberg uncertainty principle entails micro uncertainties that get magnified by releases or nonreleases of vesicles of neurotramsmitter, so that different classical describable states will exist in parallel, like the simultaneous parallel existence of the alive and dead branches of Schoedinger's cat Consciousness is associated with the `snapping of reality' into one or another of the empirically/experientially distinct versions. Thus consciousness is `caused', at least in part, by the brain that specifies the possibilities, into one of which the brain will snap. You said: > On my view > consciousness is a system or higher level feature of the > brain entirely caused by neuronal processes and realized > in the neuronal system. Am I right in thinking that you reject > this view altogether? So you said "ENTIRELY caused" and "reject this view ALTOGETHER" Quantum theory has a built-in stochastic element. Thus one does not expect to be able to say "entirely caused": the stochastic element must also play a role. In my Ann Arbor talk I described one possibility consistent with the von Neumann QT in which, apart from this stochastic element, the collapse can be said to be "entirely caused" by the brain: the evolving brain state has all the information that is needed to completely specify the evolution, apart from the basic quantum stochasticity. Since the quantum state is essentially a carrier of the information that INHERES in the conscious thoughts, and that is INJECTED into to the state by the collapse process, it becomes hard to distinguish the experience from the collapse that exactly represents it in the mathematical theory. If one identifies the experience with the collapse itself, then in this particular model one could say that the conscious experience is entirely caused by the brain, plus the quantum stochastic element. But another possibility is open: maybe the physical aspects of nature are imbedded in a larger space, which includes experiential realities, such as "pains", and "feelings of effort". The available scientific evidence does not rule out that possibility, and whereas application of occum's razor is often a good idea in science, one ought not claim that science rules out this second possibility. I said, above, 2. I think there is some causal explanation for the existence of consciousness. I believe the scientific tradition of seeking rational causal explanations has worked well and should be pushed to the limit. I am committed to the pursuit of rational causal explanation. I believe that there is a causal explanation for the existence of consciousness. The basic truth about contempory science is that it is incomplete. There is some important process going on that we do not yet understand, and whose existence is symptomized by the need in quantum theory for the participant/observer. Of course, science is a human endeavour, and it is unremarkable that we can formulate it as an interaction between ourselves and a world in which we are imbedded. But there is more to it than just that: the mathematics, which gives results that are accurate to one part in a hundred million, is naturally built as a question and answer machine, with an outside poser/receiver. Something important is going on, and our conscious experiences are just some tiny part of it. As William James stressed, one's stream counsciousness seems to play a role in choosing between options that are too complex to allow simple low-level automatic response to be adequate. Human experiences seem clearly to be playing a key role in an "evaluative" process. The causal explanation for the existence of consciousness will surely be that conscious experiences play an essential role in bringing the "other process of nature" into play in the high-level evaluation and actualization process that we associated with our streams of consciousness. Thus I believe that experiences are doing what they seem to be doing: grasping, evaluating, and actualizing macroscopic features of brain activity in a way highly constrained by, but not completely determined by, the laws and principles of QT. Overall, I think we are in essential agreement. Best regards, Henry ---------- Forwarded message ---------- Date: Wed, 11 Jul 2001 15:16:30 -0700 (PDT) From: stapp@thsrv.lbl.gov Subject: Essential Agreement with Searle? I have received several messages questioning not the details of my reply to Searle, but my final assertion: "Overall, I think we are in essential agreement." That statement contrasts with the body of my reply, in which I spell out some differences. Thus one respondent (Sid Mirsky) pointed out that: "Some time ago we corresponded about this and you were similarly in agreement with some of my views, which are diametrically opposite to those of John." Some explanation of that last statement of mine is clearly needed. First I would say that my quantum-based view is diametrically opposed to Dennett's claim that: "a brain was always going to do what it was caused to do by local mechanical disturbances." If Searle's essential position is the same as Dennett's on this key point then Searle and I are NOT in essential agreement. But Searle's views are not known for their close affinity to Dennett's, and Searle's seeming tentative embrace of quantum indeterminism at the last Tucson conference leads me to believe that he is not irretrievably wed to classical determinism. So when I said that we seemed to be in essential agrrement, it was with the understanding that local mechanical determinism was NOT entailed by his oft-made assertion that "brain causes consciousness". In the quantum universe a human brain is an informational structure that is entangled with the rest of the universe, and that undergoes periodic nonlocally implemented "resettings" that constitute the injection of the informational content of a conscious thought into the state of the brain, which is in a state of readiness to receive it. There is therefore a close dynamical two-way linkage between brain and consciousness: consciousness is not some freefloating entity that simple works its will coersively on brain. There is a dialog, and the conscious experience is caused, in part, by the presence of the appropriate receiving brain. The laws of quantum theory while not COMPLETE, are very potent. For example, they allow all the validated predictions of classical physical theory to be reproduced, and hence they do determine the behaviour of the brain to the extent that the classical approximation is adequate for describing brain behaviour. So in that classical approximation one could say that brain causes `consciousness', provided, however, that no distinction is drawn between the experiential felt realities that constitute one's stream of consciousness, and the high-level brain processes (spacio-temporal structures built out of agregates of particles and EM and Grav fields) whose actualizations are, in the full quantum treatment, the manifestations within the quantum mathematics of the associated conscious thoughts. I hope that this elaboration will prevent any misconstruals of my earlier statement. From stapp@thsrv.lbl.gov Fri Jul 13 09:02:11 2001 Date: Thu, 12 Jul 2001 18:01:37 -0700 (PDT) To: Stanley Klein Subject: Re: Free will, Stapp & QM On Wed, 11 Jul 2001, Stanley Klein wrote: > [Ethan Tarasov] > > In the 1999 JCS issue devoted to volition and > > free will, Henry Stapp made a point which I think > > many discussants are ignoring, ... that we have > > known for nearly a century that classical physics is > > neither a correct nor comprehensive explanatory > > system for the universe we encounter. > > > > Stapp makes the claim that "it is completely > > in line with contemporary science to hold our thoughts > > to be causally efficacious....". I am not stating that > > Stapp is right, but it seems to me we need to hear > > more from the physics community as to the validity > > of his arguments. Regardless of his particular theory, > > it seems unassailable that the debate needs to be > framed within the framework of contemporary quantum physics, > > [Stan] > Let's focus on non-relativistic quantum mechanics (abbreviated NQM) > since it is simpler than the full relativistic version and it > suffices to account for Stapp's conclusions. There are several points > to be made. > > 1) There are at least two ontologies compatible with NQM: Bohm and > von Neumann (abbreviated vN). Stapp uses the vN collapse ontology > where there appears to be some room for free will. However in the > Bohm ontology everything is determined and there doesn't seem to be > room for free will. Most physicists believe that Bohm's NQM and vN's > NQM give identical predictions. Stapp disagrees because he takes free > will literally rather than metaphorically (see point 4). I disagree because Bohm's theory, which has no collapses, is dynamically complete, whereas von Neumann's theory has a dynamical gap: the von Neumann theory has "collapses" which depend on choices of projection operators, and these choices are not defined by the quantum laws and principles themselves. This dynamical looseness allows the von Neumann theory to produce prediction that are nonidentical to those of Bohm's model. > > 2) Ethan brings up the issue of our thoughts being efficacious. I > presume even a rigid classical materialist would say that our > thoughts are efficacious, operating through the neural circuitry of > the thoughts. The neural curcuitry is efficacious. No one questions that. But unless the conscious thought is identically the very same thing as the neural activity it does not follow from the fact that the neural curcuitry is efficacious that the conscious thought is. If the conscious thought is not the very same thing as the associated brain activity then, at least within the framework provided by the principles of classical physical theory, one could remove or take away the conscious thought without affecting the causal efficacy of the neural curcuitry. But if removing the conscious thought has no effect then it seems improper to say that the conscious thought is causally efficacious. > > 3)... > It is > my understanding that Stapp believes that there were collapses in the > universe before complex matter was around. I think a physical system must satisfy special conditions before it can mediate a collapse. But human brains are not the only systems that satifies these conditions. Nor are biological systems the only systems that satisfy these conditions. Henry