From stapp@thsrv.lbl.gov Thu Nov 12 17:20:23 1998 Date: Thu, 12 Nov 1998 17:19:24 -0800 (PST) From: Henry Stapp To: Pat Hayes Cc: A.Sloman@cs.bham.ac.uk, bdj10@cam.ac.uk, brings@rpi.edu, brucero@cats.ucsc.edu, chalmers@paradox.ucsc.edu, ghrosenb@ai.uga.edu, jmschwar@ucla.edu, keith@imprint.co.uk, patrickw@monash.edu.au Subject: Re: Classical vs Quantum On Mon, 2 Nov 1998, Pat Hayes wrote: > Dear Henry ...> > Point 1. > > I do not claim, and never have claimed, that the existence of consciousness > follows from classical physics. Indeed I have explicitly denied that it > follows from *any* physics; ... > My point is only that > *as far as we know* it *might* follow from physics plus a theory of how > consciousness is physically implemented. You havnt given any valid argument > to reject such a theory as impossible. > Nor have I tried to. I have often noted that one can certainly tack consciousness onto classical physical theory, as an ad hoc appendage whose presence has no effect at all upon the course of physical events. My claim was rather that your body and brain could, according to the classical-physics conception, without violating any principle of classical physical theory, be exactly what it is *in regard to the trajectories of all of its atomic constituents* without there being any consciousness experiences associated with it: You could, without violating any principle of classical physical theory, be a Zombie. Thus we appear to agree that some extra consciousness-postulate, which asserts that certain patterns of brain activity either ARE consciousness, or IMPLEMENT consciousness, or ARE ACCOMPANIED BY consciousness must be added onto the principles of classical physics in order for the physical activities in your brain to entail, in the thus-expanded theory, the presence of your conscious thoughts. But this addition will have no effect on the behavior of your body or brain. [Of course, quantum effects are important for the actual functioning of your brain, but this fact is being ignored at the moment, in order to focus on a matter of principle] > So far we would seem to agree; except that I assert, but you seem to deny, > that almost all of our science is in a similar position. The existence of, > say, photosynthesis also doesnt follow from physics alone: it follows from > physics PLUS a theory of how photosynthesis is physically implemented. > Similarly for most macroscopically observable phenomena (including dials > and pointers, by the way) and most of science concerned with things larger > than smallish inorganic molecules, including all of botany, structural > engineering, etc. etc. . More care is needed here. Newton, in the Principia, explained the tides, and the trajectories of cannon balls. Of course, tides and cannon balls, and steam engines, and the wings of airplanes, and tornadoes, and thermometers and barometers are not explicitly mentioned among the principles of classical physics. These principles deal with the trajectories of tiny bits of matter moving under the influence of the forces they exert on each other. So these principles deal with the locations and motions through space of tiny particles, and hence the motions and shapes of any macro objects or systems that can be adequately conceived to BE collections of such particles. [I can follow Feynman and Wheeler and specify that the "local fields" are replaced by action-at-a-distance forces. Or I can permit the existence of numbers assigned to points whose only function is to allow the carriers of the classical forces between the particles to be loccalized.] To apply the principles of classical physical theory to "tides" or "cannon balls" one must in principle first abstract from these "normal language" descriptions enough information to identify which system is being referred to, and what its location and shape is. One then models that system as a collection of atomic particles that move in accordance with the principles of classical physical theory. This allows predictions to be made about the observed future location and shape of the system. It is only these geometric features [locations and shapes] that are directly determined by the trajectories of the constituents. Newton was able to explain the "tides" and the motions of "cannon balls" even though these terms do not appear in the principles of classical physical theory. He achieved this by abstracting just the *geometric* aspects of the observed system identified by the normal language term, and equating the observed location and shape of that system to the SAME properties of the theoretical images of the system. The key point is that the properties ascribed to the `imagined' theoretical micro elements, the atomic particles, were direct abstractions of the `experienced' location property of macro objects. Thus the experienced macro-geometric properties of an object could be imagined to be direct knowledge of the WHERENESS properties of the collections of atomic particles that the macro object is asserted by the theory to BE. The problem of the connection between mind and matter was thereby circumvented: all physical properties were geometric (WHERENESS) properties of the atomic trajectories, and we human beings were considered endowed with effective direct access to these WHERENESS properties of large collections of these atomic trajectories. [Of course, as Wm. James stressed, observations are fallible: we must cross check in multiple ways to ensure the reliability of our observations.] [And as Bohr, and philosophers of science, have stressed, our modern theories are imbedded in more ancient ones that are woven into common language, and that allow us "to communicate to others what we have done and what we have learnt". The child or trained technician can identify a "tide" or a "cannon ball", our a "falling apple", without knowing any modern science.] So my point here is that classical physical theory, even though it deos not explicitly mention specific physical objects and systems, does cover the aspects of human experience that are associated with the observered WHERENESS properties of such systems, but does not cover the properties of our experiences other than those concerning location and shapes, and their changes, without some added empirical theory about the connection of our other experiences to the geometric features specified by the theory. But then classical physical theory is inadequate as a basis for the scientific study of consciousness because it covers naturally only this limited portion of phenomena. The other parts of our experience can be tacked on, but they are only loosely connected, since they can appear only as effects of brain activity, and can be shifted around, willy-nilly, without affecting the physical reality as it is represented in the theory: they are not theoretically integral to the theory. > So, my first point: the simple fact that we do not > at present have a convincing theory of consciousness which embraces the > identity thesis (identifying conscious 'feels' with their neural > correlates) is not a good reason to reject that thesis tout court, and > still less a good reason to claim that it must be false. You constantly > ridicule me as saying that such a theory must be discovered one day, but I > do not make that claim. I think we must retain an open mind on the subject > of what the real nature of consciousness will turn out to be. > I do not ridicule. Nor have I claimed that the identity thesis MUST BE FALSE, in a broad ontological setting. But I do claim that the identity thesis is incompatible with classical physical THEORY. The point here is that classical physical theory is a THEORY that is known to be false. So it makes no sense to argue about its *ontological* features as if they were some god-given truth about nature. Classical physical theory is a useful tool for various scientific enterprises, to be constructed by us to be maximally useful. The key postulate that defines the whole classical physical theory enterprise is that the physical universe is conceived to be a space-time structure that is (1), defined by local mathematically defined physical properties, and that is (2), logically and dynamically closed: given all the physical properties at all times earlier than "now", all these properties are determined in principle by the laws of classical physical theory for all future times. It immediately follows that any property that can be either present or not present without violating any principle of classical physical theory cannot be a physical property, within the context of classical physical theory. Consciousness is therefore not a physical property, within the context of classical physical theory. I reject classical physical theory as a basis for understanding consciousness not because that approach has not yet achieved successs. I reject it because that approach would entail adding consciousness onto a theory that is already logically and dynamically complete without it. That classical approach would mean adding onto the classical ontology something that can change nothing. I reject the idea---foisted on us by an early transitory and false belief in the adequacy of classical physical theory to explain all physical phenomena---that the presence of consciousness has no effect on brain activity. > (I entirely agree with Aaron that this kind of simplistic identification is > almost certainly going to be too simple, as it is in many other sciences. > There is no way to define 'leaf' in terms of molecular trajectories, for > example, even though we all now are perfectly happy to agree that each leaf > is, in fact, a piece of the physical world and that all its properties are, > in a sense, arise from the physics of its ultimate parts. The concept of > "leaf" , like every other term in botany, supervenes on the physical but is > not reducible to it.) > A "leaf" means different things to different people, and to the same person at different times. But this word can be used to help identify some object of interest. According to the precepts of classical physical theory, any individual (token) leaf, like any other individual object, IS a collection of atomic constituents that are moving on trajectories that conform to the rules of classical physical theory. The properties of these trajectories are, according to classical physical theory, the real physical properties of this leaf, and they do not depend on any observer. A "bicycle" can be understood as a means of conveyance. But the physical properties of an individual bike, as it is represented in classical physics, although they would support various possible uses, do not include anyone's idea of how one might use this bike. So one must, within classical mechanics, distinguish the physical properties of an object from the sundry ideas about it brought to various people's minds by the ordinary words that we use to point it out or identify it. [This means that there may be an important difference between the "identity" and "implementation" approaches: according to classical physical theory a bicycle IS the collection of its atomic constituents; but its possible uses are not a part of what it IS. On the other hand, if one speaks of "implementating" someone's concept of a bicycle then the usability of the object as a means of transport could be an essential feature of the implementation. This idea of "implementation" brings the ideas of the human implementer into the process in a way that classical physics aims to avoid, by basing itself exclusively on local mechanical properties that are imagined to be devoid of any notion of purpose, use, or intentionality.] > An alternative way to make this point is to look at your title: "Can > Classical Physical Theory Provide An Adequate Foundation For The Scientific > Study Of Consciousness?" > and ask what is meant by 'adequate foundation'. In my paper with that title (Sept 15, 1998) I said: "For a physical theory to be adequate for the scientific study of a phenomena, every aspect of that phenomena must lie in the domain covered by that theory". > I see no reason why > consciousness stands in any different position with regard to classical > physics than most of the rest of the world Consciousness is different from the rest of the world, within classical physical theory, because the rest of the world is the physical world of geometric properties that are controlled by the principles of classical physical theory, and about which we can make, by means of that theory alone, verifiable nontrivial predictions. For most of the content of consciousness that is not true. > - ie, that the classical > approximation to reality which is widely used throughout almost all of > science might also be quite consistent with the presence of consciousness, It is consistent also with the *absence* of consciouness, but not with the absence of the physical part of the presently existing world. > and need not exclude a theory of consciousness which accepts this > approximation as an explanatory foundation, just as most of science does > now. Classical physical theory "need not exclude" a theory about feelings of volition. But the very aspect of classically conceived reality about which these feelings appear to inform us, namely the capacity of such feelings to influence, by virtue of their own presence, a course of action, is what classical physical theory expressly forbids: any course of action would be exactly the same whether such feelings are included or excluded. The issue is not about "excluding" a theory of conscious, but finding a satifactory theoretical foundation for a theory of consciousness. The point is that the geometric aspect of our experience plays a special role, vis a vis classical physical theory, because that theory is built directy on abstractions from that particular aspect of experience. This allows those particular aspects of experience to be imagined to provide direct knowledge of certain putative realities, apart from errors of various kinds. But nothing in the theory requires the existence of the other aspects of experience. This raises the puzzle of why reality should be like one aspect of our experience, but unlike the other aspects? Quantum theory supplies a fine answer: the physical world is not like what that one aspect tells us: it is not at all like a collection of miniature objects. The physical world, as it is represented in quantum theory, behaves much more like a giant thought. > Part of my complaint about your > overall argument is that you constantly switch from one sense to another of > 'adequate foundation' to suit the point you are trying to make. (I have > made this criticism before, but you have never answered it.) > In the communication "Classical vs Quantum", with the subject: "Can Classical Physics Provide An Adequate Foundation For The Scientifoic Study Of Consciousness?" I begin with: The premise of the argument is this: For a physical to be adequate for the scientific study of a phenomena, every aspect of that phenomena should be in the domain of phenomena that the theory can in principle cover. > > Point 2 > > One way to argue that a theory cannot explain something is to claim that > all the phenomena it can explain must have (or lack) some property which > that thing lacks (or has). In the past you have used this kind of argument > with respect to 'visual' properties, claiming that all observations must be > somehow based on sight. More recently you have claimed that classical > explanations must be restricted to 'geometric' properties, and that feels > and other subjective observations cannot be fully captured by geometry, > hence .." that classical physical theory can in principle cover only a > certain limited domain of phenomena, and that some aspects of conscious > experience lie outside this domain." While this has the makings of a real > argument, it seems not to be very convincing, for several reasons. > > First, you havnt given us any clear notion of what you mean by 'geometric'. > If we take you literally (as you sometimes seem to wish us to) then your > claim is just plain false, as any child could tell you. For example, my > cat's fur is finer on its belly than on its back, and the cat often purrs > when you stroke it. None of the previous sentence is concerned with > anything remotely 'geometric', yet it is all concerned with observable > physical phenomena which don't require us to delve into nonclassical > physics for their explanation. Examples could be multiplied forever. > I say the the diameter of a hair is a geometric property that is a direct consequence of the placement of the atomic trajectories that constitute the hair. The purring of the cat is a consequence of the placements and forms of the spacetime atomic trajectories that constitute its body, and the stroking of the cat is described by the trajectories that constitute the stroking hand and the body of the cat. Trajectories are geometric structures on space-time, according to my usage. > You say: > >A physical theory must have some rules that define how it is related to > >human experience. This rule in classical physical theory is that to first > >order our experiences of shapes and locations are closely related to the > >shape and locations specified by the trajectories: if under reasonably > >ideal circumstances an experience occurs that someone describes to > >himself and his colleagues by saying a triangle-experience has just occurred, > >then, according to the postulated connection between the classical model > >and human experience, some distinguishable set of trajectorties is forming > >a figure similar to what would be defined in analytic geometry as a triangle. > >Under ideal circumstances the shape you experience, and can describe to > >yourself and your colleagues, is asserted to be close to the shape formed by > >the trajectories that constitute the objects you are examining. > >That's the assumption that is used to tie classical physical theory to > >phenomena. > > On the face of it, this is just total nonsense. First, we see (not to > mention hear, feel, taste, etc.) all kinds of aspects of the world which > arent 'geometric' in nature. I can see the chromaticity of green and taste > acidity, for example, but they dont have shapes. Exactly! I separate the geometric aspect of experience from all others aspect. That is the basis of classical physical theory. Descartes, Galileo, and Newton separated out the geometric aspect of experience, as the basis for the classical-physics conception of the world. Geometry became king! Colors, odors, tastes, became "secondary qualities", as Locke explained: these secondary qualities have no essentially identical counterparts in physical reality, according to the precepts of classical physical theory. An extra "theory of consciousness" is needed to tie them into the theoretical description of nature. > Second, classical physical > theory is far less naive than this about how observations arise from what > is observed, as indeed it has every reason to be. Psychology knows a lot > about perceptual illusions, for example. Classical science hasn't been this > bovine since Archimedes. > Physical science is based on accepting, under ideal conditions, the idea that if many observations reveal that the location of the pointer is between 6 and 7 on the dial, then that knowledge can be used to curtail the possibilities of the locations of the trajectories that constitute the pointer. modulo appropriate uncertainties. > Sometimes however it seems that you are using 'geometric' to mean 'in terms > of particles and their trajectories'. OK, lets use the term in that way. The fact that the properties of the theoretical entities are abstractions from the "geometric" aspects of our experiences pertaining to objects allows the connection between theory and experience to be direct: no special theory of consciousness is needed. > What then does your claim amount to? It says that a theory of particles and > trajectories can make predictions only about particles and trajectories. No! The needed geometric link between theory and an observed "tide", or an observed "leaf", etc. is built into the classical physical theory. > I > entirely agree; see point (1) above. In order to make predictions about > (say) cats, therefore, we will also need an ADDITIONAL theory of how cats > are made up from particles and trajectories: how cats are implemented, > that is. Call this additional theory cat-science: then (to oversimplify), > physics plus cat-science predicts purring. But there are concepts in > cat-science which arent in physics and which arent reducible to the > vocabulary of physics. No cat-science is needed. There is "location-science" and it is classical physical theory: "cats", "tides", "cannon balls", etc., are all treated in the same way. > Your conclusion then becomes true but vacuous, Not so. Location-science covers in principle all realities that we know about, except for people's conscious thoughts, and these later cannot affect the physical realities.. > because you have retreated to such a strong sense of 'adequate foundation' > that physics provides a foundation for nothing. It doesnt even account for > the phenomena that are used to test it, since we need some account of how > particle accelerators are implemented in order to predict the observations. > > So it's hard to know what you really do mean by 'geometric', and hence to > evaluate your claim. I hope the more detailed account given here makes my meaning clear. > However, theres another, more central, problem with > your argument. You constantly insist that aspects of the phenomenal world > are not 'geometric'. For example: > > >If the phenomena of "a pain in your left big toe" occurs then that > >phenomena certainly has a geometric or spatial aspect, namely its > >"in-the-left-big-toe-ness" . But the pain aspect is neither a > >triangle-experience, nor a tetrahedron-experience, > >nor any shape-experience. > > and > > >the phenomena covered by thermodynamics, > >such as readings on thermometers and barometers, and shapes of containers, > >are geometric qualities, and hence in the realm of things covered in principle > >by classical physical theory, whereas conscious experiences have other > >dimensions. > > However, you havn't offered the slightest evidence or justification for > such negative claims. Suppose someone were to reply that you were mistaken > , and that these 'other dimensions' of experience were, in fact, > 'geometric' in nature. (Perhaps they might not *seem* geometric at first > blush, but we are all now very familiar with what were once surprising > cases of something appearing to have one nature but in fact turning out to > have a different one: heat is motion, light is electromagnetism, gravity is > space, etc.)..What response could you make in reply? > > Let me be clear: I am not making this claim, but imagining that it might be > made, and wondering how you would refute it. Because if you cannot refute > it, this shows that your larger argument rests on a key assumption - that > experience has 'non-geometric' aspects - which is crucial to your case, but > for which you have provided no support. Again, the burden of proof here is > yours, not mine: you are claiming a strong conclusion, and I am only > considering one possible response. > Yes, the burden of proof is on me. In the examples you cite, where theoretical ideas turned out to be wrong, it was theoretical ideas that were mistaken. Here we are concerned with the possibility that "color experiences" or "pain experiences" will become, through some future understanding, on a par with "location experiences". I claim that this has in fact now happened, in the switch to quantum theory. But the question pertains to classical physical theory. Classical physical theory, as it exists, is predicated on the idea that our concept of WHERENESS can be extrapolated to the subatomic scale, and that the physical realities are essentially imbedded in the local spacetime structure: at the basic theoretical level geometry is king. And the WHERENESS aspects of our experiences play a very special role because they can be imagined to give direct knowledge of macro-scopic aspects of the WHERENESS-BASED physical reality. The model of physical reality does not have qualities resembling color-experiencings and pain-experiencings that can be used in the same way. So WHERENESS experiencings play, for this reason, a special role, and they are directly tied into the basic ontological picture: the basic precepts of the theory---apart from any detailed theory of consciouness---do not allow one shift WHERENESS experiencings around without changing the basic geometric structure. This consideration must not be confused with considerations pertaining to the theory of consciousness. One may try to associate our conscious experiencings with aspects of the geometric realities that constitute our brains. This is a disconnected problem: the mind-matter problem. I have no problem with the idea that certain aspects of brain structure ARE ACCOMPANIED BY conscious experiencings. But there is a problem with the idea that certain aspects of (classically conceived) brain structure ARE (also) conscious experiencings. The problem is that every aspect of the classically conceived micro-geometric structure necessarily exists if that brain stucture exists, but there is no necessity, within classical physical theory, for conscious experiencings to exist. This difference is accommodated in classical physical theory by using "are accompanied by" rather than simply "are". > A slight elaboration of this point. You say: > > >.....Because the pain aspect of a > >pain-in-the-big-toe experience is not experienced as a location or shape > >the pain aspect lies outside the domain of phenomenal aspects covered > >by classical physical theory. > > This seems to make a mistake of confusing the nature of something with the > way it is experienced. There is no reason to suppose, within classical or > any other physics, that we experience things the way they really are. I am not confusing two different things: I am focussing on the difference. > ------------------- > > In more direct response to your comments on my arguments: > > >Let me reply to Pat's arguments. > > > >His main argument is his identity-thesis argument: he simply asserts that > >conscious experience IS a brain activity, and demands that I disprove it. > > > >But my claim is about what can be denied within the framework of > >classical physical theory: the existence of conscious experience > >in every possible classical model can be denied. > > In the narrow senses of 'adequate base' or 'entailed by', so can the > existence of everything other than particles and trajectories. No! The things to be explained are originally described in plain language. Classical physics abstracts from these descriptions the descriptions of locations and shapes of objects, and claims that our experiences about locations and shapes of real physical oblects can be understood by postulating the existence of objects built out of micro objects having specified geometric properties. These micro-geometric properties cause the macro-geometric properties to be what they are, regardless of the presence of observers. These real marco-properties are assumed to be observable by human observers, under ideal conditions, and apart from normal uncertainties inherent in observations. So within the theory one cannot deny the existence of the tides we see, or the cannon balls we fire: they are assumed to exist, and to have roughly the locations and shapes we experience them to have. On the other hand, in orthodox quantum theory it is experiences themselves that are the basic realities: the physical world is a theoretical invention of man that correctly describes CERTAIN of the connections that exist between our human experiences. > That includes thermometers, by the > way. Of course there might be what might be called thermometer-like > trajectory-assemblies, but one could consistently deny that they were, in > fact, thermometers. Unless, of course, one *defined* "thermometer" to mean > those trajectory-assemblies. Having done that - having, in effect, asserted > that Thermometer = TLTA, where 'TLTA' is a suitable description in > physics-language of thermometer-like trajectory-assemblies - then one can > go on to account for the physical properties in physics. But without such > claims of identity, nothing follows about large things from assertions > about little things. NOTHING. Maybe you will sneak these claims into the > "ordinary meaning" of words like 'thermometer'; if so, my response is that > is fine *after* enough of the science of thermometers is in place for such > a physical understanding to indeed be part of the ordinary meaning of the > word. But 'ordinary meanings' are flexible, and often follow advances in > science itself; and such a science might one day be in place for > consciousness also. > The classical-physics theorist does not invoke any special thermometer-theory or thermometer-science. He uses the common meaning of the word to identify, as almost any child of five in America could, the object being referred to by this word, and uses ordinary ideas and experiences to inform him about its location and shape. > There's no way around this logical point. If you insist that something > doesnt follow from physics *by virtue of the impoverished conceptual > vocabulary of physics*, then you have to face up to the fact that this > makes it impossible to relate physics to almost anything, and certainly > anything observable by us. WHERENESS is impoverished relative to the fullness of human experience. But it covers, for example, the classical-physics explanation of tides and cannon balls. > This applies just as much to QM, by the way, so > even within QM you have exactly analogous problems: see below. In orthodox quantum mechanics the basic realities are experiences, and colors count just as much as location in the descriptions of a phenomena. Volitional feelings are aspects of the same experiential reality, and are ontologically on a par with the rest. > > >I am not denying that one can consistently add onto the classical > >theory some postulate that adds consciousness onto the classical > >model. > > ... > >I say: If C is some "conscious > >experience" > >then the claim that C=M(C), where M(C) is a pattern of trajectories, means > >that > >M(C) must have every property that C has. But M(C) has only geometric > >properties, whereas C can have non-geometric properties, such as "pain". > > See above. What are your grounds for claiming that "pain" is non-geometric? > And your reasoning is just plain wrong. If C=M(C), and C has a property > of > 'pain', then M(C) also has that property. Its the *very same thing*: of > course it has the same properties! My argument is to first show that, within the classical physical theory framework, C has properties that M(C) lacks, and thus prove that within the classical physical theory framework, the identity thesis C=M(C) is wrong. > What you should have said is that C has > properties which are such that there is no way to conclude that M(C) has > them from classical physics. A careful discussion of your claim will, I think, get to the core of our differences. An individual atomic trajectory in spacetime is a geometric structure, in my vocabulary. What about a pattern of (very) many such trajectories? Viewed microscopically M(C) is just a (very) much more complex geometric structure. So the properties of M(C) would, from this microscopic perspective, be "geometric". The simplest of the geometric properties of this pattern would be just the locations and shapes of certain subsets of closely packed trajectories. These are the macro-geometric properties that much of classical physical theory focusses on, and that I have been focussing on. But some particular complex many-atom system evolving in accordance with the laws of classical physical theory could have regularities that might ascape notice if viewed or conceived microscopically. For example, in a computer carrying out the instructions some complex program, there might be regularities that would not be apparent to a battery of observers, each watching only one memory location. One would need to know what to look for, and how to be thinking about what one sees, in order to see any regularity. This regularity could amount to new "laws" governing appropriately singled out features of the complex pattern of trajectories. These laws might be termed "geometric" in one sense, since they are just subpatterns within a complex geometric pattern. But another viewpoint would be that these feature are best thought about in some logical space in which the significant features of the particular dynamical system are taken to be the basic degrees of freedom. A human brain is, according to the precepts of classical physical theory, a complex pattern of atomic trajectories. It is pretty clear that we are not consciously aware of the micro-geometric structure of the patterns of atomic trajectories in our brains. We are aware, apparently, of functional aspects of these brain patterns, and informational structure connected to actions. So the human brain, classically conceived, seems from this function-based perspective, rather than the geometric one, analogous to a practical-minded overview of the activities of a computer. How does this view relate our problem? Classical physical theory was designed to deal with the information about the world that comes through our senses. It gave a conception of reality in which physical reality was composed of a myriad of atomic space-time trajectories, certain features of which, when conveyed to us through our senses, and processed by someone's brain, became a reasonably accurate picture of what was going on not in his brain, but in the external-to-his-brain real world. Within classical physical theory a pattern of brain activity is a well defined reality: it is exactly a collection of atomic trajectories in space-time. This pattern may have complex features that are best described in a simpler form. But the mere existence another description does not, within the framework of classical physical theory, entail the existence of any other ontological reality: it means only that there exists some other way of describing the pattern that is simpler, and perhaps more useful for some purposes. This reality, be it described in full microscopic detail, or only partially in some abbreviated---but perhaps more useful---form, is supposed, in classical physical theory, to exist in its one uniquely described micro-geometric form, and to be nothing beyond or in addition to that reality as it is thus described. And you have affirmed that the principles of classical physical theory do not entail the existence of the experiencing of redness. But then the claim that an aspect of such an existing pattern of brain activity IS an experiencing of redness entails that this physical reality IS something beyond what classical physical theory requires it to be. Yet classical theory says that this reality IS nothing beyond what classical physical theory requires it to be, which is exactly the micro-geometric stucture. > But, to repeat, there obviously is a way to > conclude it from classical physics plus the claim that C=M(C); and you > havn't anywhere argued that to add this would be inconsistent with > classical (or any other) physics. > One cannot add C=M(C) to classical physical theory because in the existing word the brain pattern of trajectories is entailed by the principles of classical physical theory alone. But you affirm that the existence of C is not entailed by the principles of classical physical theory alone. Hence they cannot be identical. > Look, Henry. I can kind of empathise with your position here, as I'm sure > we all can. When one looks inside oneself, as it were, it hardly seems > credible that our experiences can ever be identified with some > electrochemical goings-on in a brain. They seem to *feel* so different. But > the problem with making this into an argument is that we really have no > idea what it would feel like (to use Nagel's famous criterion) to be a > collection of electrochemical goings-on in a brain. Maybe it would feel > exactly like this! And if it did, I have no problem with the idea that a brain activity HAS a feel: My problem is with the idea that the classically described brain activity IS *also* a feel, but not necessarily so. > then there would be no objection to > saying that's what it, in fact, is. This is not to claim that it must be, > or even that it is, that (though there are other good reasons for thinking > so) but only that it *might* be: there's nothing to show that it *couldnt* > be. It seems to me that whenever you come up with an argument that it > couldnt be, I can imagine a defiant student who just acts contrarian and > just says 'Yah boo, yes it could!', and his position would still be > consistent. Yah boo, pain *is* 'geometric', he'll claim, in the same > spirit: prove me wrong! And as I stand here on the sidelines, I can't see > any way you could. The problem is that according to classical physical theory all aspects of the physical world are necessary: there are no loose parts. Geometric features are not loose, but pains are. > > >Aaron, citing the weakness in Pat's identity-theory approach that I have just > >exploited, takes a different tack: implementation theory. > > > >An analogy between "temperature" and "consciousness" is often cited > >by proponents of the idea that conscious is simply a property of a > >physical system that can be adequately represented in terms of the concepts > >of classical physical theory. But the phenomena covered by thermodynamics, > >such as readings on thermometers and barometers, and shapes of containers, > >are geometric qualities, and hence in the realm of things covered in principle > >by classical physical theory, whereas conscious experiences have other > >dimensions. > > Temperature is not a reading on a thermometer. Temperature can be felt > directly by our skin, and the experience of temperature is as elementary, > unstructured (and non-geometric) as seeing a color or hearing a voice. > Again, your argument here changes the rules by pre-substituting a concept > from a science with the original concept needing explication. The very idea > of a thermometer only became possible when people realised that liquids > expand when heated, a moment quite far along the conceptual history of > 'temperature'. "Temperature" can be understood in different ways. In the psychological sense you are using it is in basket with color and odor and feeling of volition and it is only loosely defined. The temperature that enters onto thermodynamics and stat. mech. has been measured to tiny fractions of a degree, and the conversion factor to energy of measured to five figures. The reduction of thermodynamics to stat. mech. is often cited as an analogy to the expected reduction of "folk physchology" to "neurophysiology": it was this analogy that I was referring to when I said both were geometric. > ..... > > > >Note that in pragmatic quantum theory no such problem arises: > >the primary elements are experiences of any kind that can be described > >to one's self and one's colleagues, and the brain correlates of such > >experiences. > > Now let me turn to this claim (which you keep reiterating) and challenge it > directly. Your own theoretical castle seems to me to be just as rickety as > the classical one, if not more so. > > First, you say that QT's primary elements are 'experiences', but these > strange things are, as you have already conceded, nothing whatever like > human experiences. The pragmatic approach is based on human experiences that we can describe to ourselves and to others. > First, they occur everywhere, and were occurring even > before there were stars or galaxies, let alone humans, so they have nothing > particular to do with our subjective experience. Second, in your account > these 'experiences' must be a - perhaps the - central aspect of the > universe, yet you seem to agree that human consciousness might never have > evolved. But most important, I see nothing anywhere in QT about human > experiences that can be described to one's self and one's colleagues, even > in your own writings. The Copenhagen/Solvay27 interpretation is based on "communicate to others what we have done and what we have learnt"(Bohr). Please read my article "The Copenhagen Interpretation" in MM&QM: if you are not acquainted with this most basic idea of QM then we are in non-communicating universes. > For example, where does QT make any predictions about > pain, or even why pain should exist at all? How could any physics, even a > physics of 'experiences' , account for - ie predict from its principles > alone - the nature of the experience of, say, seeing a rainbow emerge from > a thunderstorm in the desert, or wanting to comfort a crying child? No > physics, including QT, mentions such matters. You miss the basic point. The pragmatic approach takes all experiences that we can describe to ourselves or to others as the primary realities, and regards the physical theory of the underlying physical system, namely the associated brain, as a way of representing certain correlations between these experiences, and also the experiences of outside observers. All describable/communicable experiences appear on a par. For large parts of the theoretical structure classical ideas are adequate., But characteristic quantum effects can be important under certain conditions, and consciousness is freed from its slavish role of pure effect: it appears as a more co-equal partner with brain in the mind-brain cause and effect relations, as has been shown in recent publications. > Even your panpsychic > post-Bohrian vision is pathetically inadequate as a theory of human > consciousness. Please!!! do not confuse me with Sarfatti! Pragmatic is almost the opposite of panpsychic. > Now of course it may be that it could, one day, be supplemented by a theory > of conscious experience. Pragmatic QT theory IS a theory of consciousness: it does not need to be supplemented by one. > That is, a theory might emerge which explains > consciousness in terms of QT. But this theory will not be QT itself, and it > will not follow from QT; in fact it couldnt, for exactly the reasons that, > as you point out, classical physics cannot, alone and unaided, tell us > anything about consciousness: because the entire vocabulary of QT, just > like that of the rest of physics, simply makes no reference to the topic > that needs explanation. > You are WAY off the mark: the basic vocabulary of pragnatic QT is the vocabulary of consciouness. > Best wishes > > Pat Hayes > > --------------------------------------------------------------------- > IHMC, University of West Florida (850)434 8903 home > 11000 University Parkway (850)474 2091 office > Pensacola, FL 32514 (850)474 3023 fax > phayes@ai.uwf.edu > http://www.coginst.uwf.edu/~phayes > Best regards, Henry