In the course of the previous discussion of the unity of consciousness and physicalism, I got som responses from Mike Wiest, who took a position that anti-physicalist arguments work against physicalism if the "physical" is understood in terms of classical physics, but quantum mechanics opens the door to answer the questions posed by these arguments. My initial reaction was that this was a form of scientific idealism and a rejection of mechanism at the level of fundamental physics. I sent the link to Stapp's paper, which Wiest recommended, to William Hasker, who responded as follows:
Greetings! Your query about Wiest’s message came at a (relatively) good time – no major projects are underway at the moment, and I am pretty well caught up on F & P stuff. So, I printed out Stapp’s article, and have been trying to figure it out.
To begin with, I think Stapp does have a fairly good grip on the unity-of-consciousness argument, and on the evolutionary version of the Argument from Reason. Roughly, the idea seems to be this: a “thought” – say a belief – typically involves nervous activity in widely scattered parts of the brain. But, on classical assumptions, each micro-area within the brain is in direct causal contact only with immediately adjacent areas; also, the physical description of what is going on at a given point in the brain (i.e., values for the several physical “fields” at that point) is far too simple to register a complex state of consciousness. So consciousness, if it exists, must be something “external” to the brain, but then (assuming causal closure) it would have no effect on behavior and would confer no evolutionary advantage, and would thus be scientifically inexplicable. This is pretty rough, and it’s a mixture of what he says and some of my own ways of putting things, but I do think it basically captures what he is saying up through section 2.
The tricky part begins in section 3. I’ve tried to figure out the mathematical notation; it doesn’t help that parentheses have got converted into tildes, and some guesswork is involved in putting them back! I think I’ve got a fair grip on what he is saying up through 3.5. But what he says about the quantum-mechanical description of a system leaves me in the dust. I can to some extent interpret the formulas, but I have no idea what they represent or what the point is of describing the system in the way he sets out. So for present purposes, I have to take it on faith that he knows what he is talking about. But the payoff (in 3.9f) seems to be this: the quantum-mechanical description of a system (such as the brain) is enormously more complex than the classical description, such that (I hope I’ve got this straight!) a description of what is going on at any one point involves the simultaneous description of what is happening at all the other points in the system. Thus, the quantum-mechanical state-description, unlike the classical state-description, is sufficiently complex to correspond to a belief or some other complex state of consciousness.
This amounts, in fact, to a kind of ontological holism: “The fundamentally holistic character of the quantum mechanical description [of] nature is perhaps its most basic and pervasive feature” (3.12). And this does respond to the challenge of the UOC argument: to account for the UOC, we need something that functions holistically rather than atomistically, as physical reality does on a classical model. Actually, 3:11 is the bit that best summarizes the point of this section as a whole.
So far, this does not tell us why thought is involved in the quantum-mechanical process. (Note that all of the above would apply to any physical system, not just to the brain.) I take it the following section is supposed to help with this. Or rather, to point us in the direction of other work of the author’s (surprise, surprise!) that does the job. The big promissory note (so far as the present article is concerned) is the claim that the author’s theory “appears to be able to explain in terms of the laws of physics the causal connections underlying human behavior that are usually explained in psychological terms” (4.7). My reaction, as you may surmise, is along the lines of: “This blank check and a dollar bill will get you a can of pop out of the machine.” Of course, the author apparently has made an effort, in his book, to cash out the promissory note. My instinct, however, is that the Argument from Reason is going to kick in here, and I see nothing that suggests he will have a good answer to it.
The “Conclusions” (section 6) summarizes very nicely the limitations of classical physics (as captured by the UOC argument) in providing an understanding of mentality. The way in which quantum physics overcomes these limitations is, unfortunately, not spelled out with equal clarity.
Appendix A gives some of the basics of the author’s theory, which strikes me as extremely interesting though highly speculative. (Incidentally, I believe David Chalmers has recently come out for something roughly along these same lines.) It’s possible that the holistic character of quantum mechanics can be used to account for the holistic nature of thought. But I see nothing so far that shows me that Stapp has crossed the divide (or perhaps, even seen clearly the divide) between the “mechanistic” nature of matter and the intentional and teleological character of thought, as featured in the AFR.
I guess I’ll leave it at that, for now. Does this help at all towards clarifying your perplexity about the material? And, do you have any further thoughts to share? This really is interesting stuff, though the author has lots to learn about writing for non-physicists.