Comments on Searle's Tucson 2000 talk. This is an effort to spell out the relationship between Searle's third millenium position and my quantum mechanical one. Searle reaffirms his longtime themes: 1. "Consciousness is a real biological phenomena!" 2. "The key features of the consciousness as I define it are its qualitative and subjective characteristics. What I mean by that is that for every conscious state there is a certain qualitative aspect to the state. There is something that it is like, or something that it feels like, to be in a state of that type." 3. "This unified field of conscious, subjective awareness is not reducible to any third-person phenomena" 4. "All of our conscious states are CAUSED BY lower-level neuronal processes in the brain" 5. "All of our conscious states are themselves features of the brain" (e.g., Neural activity "causes me to feel a pain. What are these pains? The pains themselves are simply higher-level features of the brain,... they are themselves features of the system of neurons that constitute the brain.") Comment: There is a tension between claims 3 and 5 that needs to be defused. This tension hinges on the meaning of "brain". In normal contemporary usage in science, and I think philosophy, a person's brain is the collection of the neurons and other pieces of matter that lie in the person's skull. This would include the atoms and molecules in the skull, and electromagnetic fields that exist in the skull and transmit forces between the charged particles. Within the theoretical framework of classical physical theory all of these components of the brain are regarded as objective (third-person) quantities. Within the conceptual structure of classical physical theory the brain is an objective third-person structure, or system. Unless it is otherwise announced, the presumption of an educated reader would quite rightfully be that the brain is what classical physical theory takes it to be, namely a third-person entity/system/structure: a person's brain is a structure that can be completely described in the third-person (objective) language and conceptual framework of classical physical theory. Given this "normal" meaning of the word "brain", there appears to be a conflict between claims 3 and 5: 5. "All of our conscious states are themselves features of the brain" (e.g., Neural activity "causes me to feel a pain. What are these pains? The pains themselves are simply higher-level features of the brain,... they are themselves features of the system of neurons that constitute the brain.") 3. "This unified field of conscious, subjective awareness is not reducible to any third-person phenomena" Superficially, 5 seems to be saying that consciousness IS just a feature of the third-person neural activity that constitutes the brain, whereas 3 asserts that no such reduction to third-person elements is possible. Some explanation is needed about how this apparent contradiction is to be avoided. It is not clear how Searle resolves this tension. One possibility hinges on a careful analysis of claim 2. He says that "for every conscious state there is a certain qualitative aspect to the state. There is something that...it feels like to be in that state." Maybe he is suggesting that `the conscious state' itself is a purely third-person brain state, but that `being in' that state is different from the mere actual existence of this physical state: maybe he is postulating (without mentioning it) the existence of a conscious agent that can BE IN this purely physical brain state, and is associating "This unified field of conscious, subjective awareness" not with the third-person conscious brain state itself, but with this conscious agent's BEING IN that third-person state. Another possibility for how he reconciles 3 and 5 is that he is abandoning (without mentioning it) the classical physics conception of the `brain' as a something that is described in third-person terms. That is, he might simply be rejecting the normal meaning, or conception, of "brain" as a third-person structure, and amalgamating into "brain" both the usual third-person properties and the first-person "feels" that accompany them. If the apparent conflict beween 5 and 3 is to be resolved by this simple revision of the meaning of the word "brain", or the term "features of the brain", then the switch to this enlarged meaning ought to be duly stressed. But the underlying difficulties pertaining to causation, and are not resolved by mere redefinitions. I find in Searle's book "The mystery of consciousness", on pg. 31, the following explanation: "The sheer qualitative feel of a pain is a very different feature of the brain from the pattern of neuron firings. So you can get a causal reduction but not an ontological one." This argument seems quite analogous to the argument that neuron firings CAUSE electromagetic fields in the brain, but, since the elecromagnetic field in the brain is a different feature of the brain that neuron firings, the former cannot be reduced ontologically to the latter. But this ontological difference between neurons and EM fields does not get around the fact that because the EM field in the brain is a feature of the brain it can, by virtue of this fact alone, and what "the brain" normally means, be "reduced" to a third-party phenomena. Again it seems that Searle's argument involves rejecting the normal classical idea of the brain as something fully describable in third-party terms. In order to reconcile 3 and 5 he seems to be switching from the normal conception of what the word "brain" means to a conception that allows BRAINS to have experiential features that are caused by the "lower-level neuronal processes". However, according to the concepts of classical physical theory, what is CAUSED by a physical structure is nothing but the changing shapes and locations of the aggregations of physical particles, and the numerically described values of the (elecromagnetic and gravitational) fields that are caused by them. So Searle seems to be positing some modification of the ideas and principles of classical physical theory, without actually saying that he is doing this, or specifying the rules of the new psycho-physics that he is proposing. 4. "All of our conscious states are CAUSED BY lower-level neuronal processes in the brain" Searle claims that conscious states are CAUSED BY lower-level neuronal processes. I presume that he means that the neuronal process are sufficient causes for the occurrence of the conscious states that occur: that other conscious states are NOT parts of the cause of a succeeding conscious state. That is, I presume that 4 means 4'. "All of our conscious states are CAUSED BY lower-level neuronal processes in the brain `ALONE': the state of conscious not only `supervenes' on the neuronal processes, but is caused by the neuronal processes alone. Any causal efficacy of the conscious state is VIA the neuronal process. This interpretation is supported by the following passage from his "Rediscovery of the Mind" p.126: "The solidity of the piston is causally supervenient on its molecular structure, but this does not make solidity epiphenomenal; and similarly, the causal supervenience of my present back pain on micro events in my brain does not make the pain epiphenomenal." Some of the issues here are mere matters of definition: How is the word "brain" to be defined? Thus some of the capacity of Searle's rhetoric to reduce the whole mind-matter problem to trivia resides in his apparent shift to an enlarge meaning of "brain" and "features of the brain". But the real issue is not thereby avoided. This real issue is the issue of CAUSATION: Is our consciousness really doing something that is beyond what third-person-described brain activity by itself already fully causally determines? Searle wants to reject epiphenomenalism. His position is that consciousness is efficacious simply because consciousness is an efficacious feature of brain activity. But what is the causal structure? I think Tucson 2000 mark a huge shift in Searle's position on causation. He describes two possibilities for the causal structure. The first is bottom-up causation: the micro-level is causally sufficient to determine everything. Thus just as micro-level causation determines the solidity of the piston, which accounts for the causal efficicacy of the piston, so, according to this bottom-up causation scenario, is consciousness causally efficacious by virtue of bottom-up causation. This first possibility was, it seems, his position in "The Rediscovery of the Mind." At Tucson 2000 he says of this bottom-up scenario that it is "more intuitively plausible", but: "This result is very intellectually unsatisfying, because, in a word, it is a form of epiphenomenalism. It says that the pschological processes do not really matter. The entire system is deterministic at the bottom level, and the idea that the top level has an element of freedom is simply a systematic illusion." He argues against this possibility of evolutionary grounds (as did Wm. James): There would be no reason for the elaborate system of human consciousness to have evolved if everything is determined without it. This pushes him toward the second possibility, which is that the micro-level is not causally complete, due to quantum indeterminacy, and hence that the temporal causal development could involve consciousness in an essential way. But HOW does consciousness enter into the dynamical evolution of the combined mind-brain system? That question is left unresolved. This question is, of course, just the basic question in this field. Classical physical theory does not seem to provide any adequate basis for attacking this problem, but quantum theory resolves it almost automatically. If one is going to abandon the classical-physics description of the brain, and move to a conception in which brains have features that are "subjective", in the sense of incorporating aspects of the field of consciousness, and in which quantum indeterminacy is important, then it would seem reasonable to try the replacement that physicists have already created. That theory brings in quantum indeterminacy in a mathemathically controlled way, and specifies the details of the dynamical interplay between conscious experiences and objectively described brains. The von Neumann and Wigner formulation of quantum theory accounts in a mathematically and logically consistent way both for the classically described objective features of nature and for the quantum corrections to the classical description. It makes consciousness efficacious in brain dynamics in a way that seems to accord well with all the psycho-physical data, including the Libet data the Searle mentions to support his idea that consciousness is playing a significant role in brain dynamics. The situation, in brief, is this: The mathematical rules of quantum theory have a causal gap, which is the need for certain questions to be asked. This opens the door for a high-level role of consciousness. On the other hand, "decoherence" effects would seem to block any significannt role for high-level macroscopic quantum effects in the brain. However, there is one quantum effect that is not blocked or reduced by decoherence. It is the Quantum Zeno Effect. This QZE effect allows allow mind to affect brain dynamics apparently in just the way demanded by the psycho-physical data that connects conscious process to brain process. I see Searle's third millenium position as generally in line with this quantum approach, though it lacks the detailed conceptual framework and the specific computational rules that quantum theory provides. ------------------------------------------------------------------ A final issue concerns the need for an element of chance, or happenstance, if the causes are insufficient to determine the actually occurring outcome. Searle allows the causal gap to be filled by the action of a conscious agent acting on a reason. But if the agent could act either way, i.e., if nothing determines which choice he makes, then it would seem that an element of happenstance would still be is present. If, on the other hand, given the reasons, the agent's choice is determined by some causal chain then there is again, in the fullness of the situation, a sufficient cause for what happens. So I do not believe that Searle has successfully evaded the two horns of the dilemma: sufficient cause; or a choice without a sufficient cause (i.e., a happenstance). [I have had a very long e-dialog on this issue with David Hodgson , and the matter seems quite clear to me.] NB: The quotes used above were taken from a very unofficial first draft, and they many not represent Searle's final words. But most of them are statements of his longstanding positions, and the few pertaining to quantum indeterminacy and what I have interpreted to be his new position on causation were, I am told, close to what he said in his talk.