This is a comment on the Sept 23 postings of George McKee and Kerry Langer. Kerry Langer says: "There is a fundamental divide between those who take consciousness (or intentionality or subjectivity or meaning) to be a "real thing" in the sense of its having some sort of intrinsic nature or "essence" and those who regard it more as some sort of useful construct. Frankly I'm amazed at how ready many people are to assume that intentionality is an inner some*thing*. When Henry Stapp (21 Sep) refers to "the flow of experience in some real physical system" or to "the subjective aspects of nature" what does he *mean*? This is a philosophical issue which must be addressed if progress is to be made. Against Pat Hayes he argues that the analogy between the quest for an "elan vital" and the quest for the nature of "the subjective" is misleading: "one *must* examine the actual case in order to produce a solid argument". Exactly. However in order to "examine the actual case" we need to analyse the notion of "the subjective" (or the intentional) rather than just assume that this is a "thing" which exists. And this is a philosophical issue. If our concepts are just wrong and need reformulating we can only go in the wrong direction." Certainly I am in no way opposed to philosophy, or metaphysics in the sense that Wm. James defined it as a particularly intense effort to think clearly. Indeed, Klein would like to say that what I am talking about is nothing but metaphysics. But the kind of philosophy/metaphysics that is needed here is of a particular kind: a kind that does not separate philosophy/metaphysics and physics into two disjoint realms. It is of the kind that seeks to construct useful testable physical theories that are adequately connected to what we can know. The essence of the Einstein-Bohr debate was about the "metaphysical" issue of how to formulate basic physical theory: it was both physics and philosophy. Einstein said that in his opinion: "Physics is an attempt conceptually to grasp reality as it is thought independently of its being observed. In this sense one speaks of `physical reality'. In pre-quantum theory there was no doubt as to how this was to be understood. In Newton's theory reality was determined by a material point in space and time; in Maxwell's theory, by the field in space and time. In quantum theory it is not so easily seen. ...." Bohr's position was that science was about what we could know: that in the final analysis our physical theories are, as Einstein agreed, just inventions of the human mind that we find useful for the organization and expansion of "our experience". There was no disagreement on that point, which is a philosophical conclusion about our physical theories. Einstein thought that, nevertheless, one ought to base our basic theory on the classical concept of the local (in spacetime) field. Bell's theorm and Aspect's experiment has now surely shown that option to be non-viable. Bohr thought that our experiences should be recognized as a legitimate reality that could enter into physics theory. As a real part of nature it would presumably have some sort of "essence", but does not mean that it "was" *the essence*, not intertwined with other aspects of nature in some complex interpenetrating way. But it *was* a part of the whole reality, and hence could be taken as a part of reality that one could build a useful physical theory upon. This sort of analysis is "philosophical", but it is connected to physics because it deals with the question of how a useful physical theory can be formulated. Of course, our experiences are surely not the totality of reality. So one would like to have a rationally coherent theory that puts these parts of reality into a larger cohesive theory. Heisenberg, von Neumann, and Wigner showed how Bohr's idea could be expanded to accomplish this. Langer's posting begins: "Like Anthony Goodman, I also feel compelled to ask why *any* kind of physics should be expected to lead toward an explanation of consciousness/subjectivity? " But of what does an "explanation" of consciousness consist? In what sense does `science' explain such a thing? Scientific theories allow us to organize our experiences, and make useful testable prediction about what we can expect to experience in certain sorts of situations. Experiences are part of the totality of reality. If we have an extensively tested and adequate theory that explicitly puts our experiences into the theoretical structure in a particular way, which is basically different from the way that particles and fields enter, have we explained what consciousness is? All that we have is a way of understanding how our consciousness could fit into the rest of nature in a rationally coherent way; a way that explains in principle why the contents of our experiences are what they are, and how they can do what they do. George McKee says: "... I want to comment on the "vitalism analogy": As Henry has pointed out, this isn't a rational argument for or against the possibility of any theory of consciousness. What it is, is a historical argument against the irrational confidence of those who confidently (some might say arrogantly) assert the correctness of their particular hypothesis." I have given an *argument* to support my contention there is a clear distinction between the *consciousness/subjectivity disjunction within the framework of classical mechanics* and the other cases. This argument is that an examination of the principles of CM shows that these principles provide no way of passing from objective to subjective. Confidence based on a valid argument is not irrational: rather it is irrational to ignore a valid argument simply on the grounds that invalid arguments for false conclusions have often been given in the past. To repeat my earlier quote: Einstein said that in his opinion: "Physics is an attempt conceptually to grasp reality as it is thought independently of its being observed. In this sense one speaks of `physical reality'. In pre-quantum theory there was no doubt as to how this was to be understood. In Newton's theory reality was determined by a material point in space and time; in Maxwell's theory, by the field in space and time. In quantum theory it is not so easily seen. ...." The fact the Einstein could clearly see that classical mechanics was about objective physical reality, and ceaselessly objected to Bohr's attempt to introduce something foreign to classical mechanics, does not mean that this (I think) universal view of physicists about what classical physics is about is correct: one must continually re-examine our arguments on such deep matters. But I think the only correct way to challenge such a seemingly secure point is to look at the arguments again. Analogies can be useful to direct us to a re-examination of the arguments: maybe the proof of Pythagoras's theorm within the framework of Euclidean Geometry is wrong, and some consideration might encourage one to examine the proof anew. But once suspicions are raised one must go back and look again to see if there was a mistake: an argument by analogy cannot dispose of a valid proof. The fact that Bell's theorem and Aspect's experiment effectively prove that nature cannot have the *macroscopic* (on the scale of meters) behaviour that classical mechanics entails, but has rather the precise behaviour that quantum mechanics correctly predicted, certainly dispose of Einstein's view that classical mechanics could be, *even on a macroscopic scale*, an adequate foundation for a conception of physical reality. McKee says, later on: " But what some do appear to take seriously is that there is some nonmaterial, metaphysical C that is inside their own heads. Stapp's position is that this C is an intrinsic part of quantum theory, and I can accept this view of QM as an important stage in the history of science. But what I fail to understand is how to operate the theory to derive how Henry Stapp or anyone who agrees with this can show that I am conscious. " The view of Bohr was that the experiences of the community of communicating observers was the foundation of science. He focussed on certain particular kinds of experiences, namely the ones that could be characterized as experiences of " classically describable" aspects of the world about us. He himself did not enter much into the question of the connection of these experiences to what was happening in our brains. But Heisenberg, von Neumann, and Wigner did so, and came to a theory that associated our experiences that Bohr considered an appropriate basis for physical theory with certain "events" in our brains. These events were "collapses of the wave function of QM" to forms compatible with our experiences. Thus our experiences became associated with certain features of the physicist's theoretical model of nature. This is but a stage in the history of science: one certainly can look forward to future changes perhaps more "radical" than this. But this is a step beyond classical mechanics because it brings certain aspects of reality that were not dealt with explicitly within CM explicitly into the physical theory. It places explicitly into the theory, in a causally efficacious role, certain elements of the totality of reality, that were neither explicitly mentioned nor entailed by the principles of classical mechanics, nor encompassed within what is entailed. How does the theory show that you are conscious? Notice that the theory does not seek to create human consciousness from nothing: it merely gives something known to exist, and in fact the basic reality of our science, a place in the theoretical scheme. Now we come to the part of the theory that still needs to be described in more detail, and where more experimental information is needed, to guide the working out of details. Although the general principle that the collapse will be to a form compatible with the experience is specified, the details are not yet fixed. But different options lead to different behaviours, particularly as regards speed in finding satisfactory solutions of search procedures. Once these details are in place one would, theoretically, be in a position be to empirically determined whether a collapse of the required kind has occurred or not in your brain. Thus we have a theoretical framework that is not yet completely specified, and has not yet received any direct empirical confirmation. But it is a rationally coherent theoretical framework that does give a generally well defined explicit place for our consciousness, and is in principle testable, and, in contrast to CM, is at least a possible theory that is in accord with the *macroscopic* empirical facts. In connection with my argument that CM does not *entail* the existence of consciousness McKee asks, in effect, what my definition of the subjective is. Drawing from Einstein's comment we can define the objective aspects of nature as : " Reality as it is thought independently of its being observed. " That is just the sense that I used it in my argument: it is a theoretical notion of the thought of an abstract observer that can somehow know things from afar without actually being part of the real physical universe, or interacting with it. The subjective/conscious/phenomenal reality is the thought of real embodied (say human) observers that know through causally interactive observations. The Einstein-Bohr debate was a controversy about whether the theoretical concept of the objective, defined in this way that physicists know and understand, and that is what classical mechanics deals with exclusively, is adequate as a basis for physical theory, or whether a physical theory able to accommodate adequately the empirical evidence needs to be formulated in subjective terms, i.e., in terms of the thoughts arising in real embodied observers from real physical acts of observation. Classical theory might indeed be able to describe, from within the objective framework in which it is formulated, the behavioural activities that are associated with our conscious experiences, and it might then be possible to augment CM by appending to it some extra principles that would postulate this observed connection. But the principles of CM itself can produce only prediction or conclusions that stay within the confines of the theory: it is about "physical reality" understood as "reality as it is thought independently of its being observed." There is no principle within CM that allows for a leap outside this abstract theoretical framework to one that encompasses, as QM does, the thoughts of real observers. Einstein thought very long and hard about these matters, and described his conclusions clearly in the book mentioned below. I unreservedly recommend what he has written there to anyone interested in these questions. Henry P.Stapp Ref: Albert Einstein: Philosopher-Scientist. Tudor, New York. 1952 ed. P.A. Schilpp. p. 81.