The issue of brain/mind irreducibility is crucial for several reasons. First because people tend to equate soul with mind and as such they often take reducibility as proof that the only existing things are naturalistic. While it is possible to maintain a spirituality that is based upon a naturalistic mind as the physical product of brain, the possibility of mind as a basic product of nature and irreducible offers the prospect of a dimension not reducible to the physical and thus shatters naturalism/materialism from the outset. It is also possible to produce God arguments based upon a non reductive reading of mind. Moreover, the reductionist reading provides the basis for deterministic ideology that threatens to reduce the value of humanity and to eliminate he integrity of human agency.
Theoretically non Reduceable.
By way of explanation of the two sides, I will take property dualism as representative of the pro-mind side, on the proviso that it’s not the only position. Panpsychism can be thought of as a subset (one of four types) of property dualism. I will compare them with John Searle’s article “why I’m Not a Property Dualist.”
Searle summarizes the property dualist position:
(1) Empirical reality exits in two categories, physical and mental.
(2) Because mental states are not reducible to physical states they are something over and above the physical. The irreducibility in and of itself is enough to demonstrate that there is more than just the neurobiological.
(3) Mental phenomena do not constitute separate objects of substances but rather are features of properties of a composite, such as human or animal. Thus humans or animals have two types of features or properties, mental and physical.
Searle takes issue with this in that he ascribes the categories to just one world. There are not two sets of characteristics. We have one world, everything is physical, but we can describe it in a number of ways. Searle may be thought of as part of the pro-mind side, but he is not a property dualist. He explains why in terms of the problem of the mental and the causal. If the mental is removed from physical then it can’t play a causal role. Ultimately he’s going to argue that the conventional terms are the problem because they invite us to discuss the issue in dualistic ways. So Searle accepts the premise of the reductionists that everything is physical and material but he can’t be called a reducationist because also recognizes the importance of ontology. He says neurobiological there is one world and consciousness is a product of the causal process. On the other hand, since descriptively our mental states are not reducible or accessible by others there is an ontological dimension that can’t be reduced. He seems to take the ontological as a descriptive dimension. As argument against the ramifications of Property dualism he lays out a dilemma. If consciousness is closed from the physical realm its not part of the causal mechanism and that means our behavior has nothing to do with consciousness. The alternative is that if the conscious is part of the causal it creates a dualistic causality in which case each action has two explanations, the mental and physical. It seems rather coherent to me to appeal to the mental as motivation for movement and to the physical as the actual mechanics of carrying out the “enabling legislation” so to speak.
I agree with Searle that a large part of the problem is the dualistic nature of language. We are forced into categories of dualism by the way we are led to speak about the distinction between physical and mental. I can accept Searle’s position, even as a Christian, with the proviso that we can’t understand God and God is obviously an exception to what we know and could contradict all of it. The qualities in humanity that make us “eternal sprits” and put us above the realm of the mere physical can be described in functional terms rather than taken as “essentialist.” That is to say, we can see “spirit” as mind, and mind as mental phenomena without positing a discrete entity or ghost in the machine. On the other hand I hold back from commitment to Searle’s position due to one question that he doesn’t seem to answer. When we say “consciousness” do we mean the actual awareness, or even the texture of mental awareness that comes with mental states, or do we mean the apparatus that makes that texture possible? That seems crucial because if we mean the apparatus then I would agree with his position in so far as we stipulate for biological life only; for biological life consciousness is rooted in the neurobiological. We need not confine our understanding of the texture of awareness or the function of awareness to biological life. If the texture is what we mean by “consciousness,” then it could be much more vast and irreducible to the neurobiological. This is an explanation of the term “source of consciousness.” That term I apply to God.
I think Searle is wrong in assuming that two dimensions of human being (mental and physical) make for two causes in every action. One cause beginning with the motivation (mental) and working itself out as a cause over two dimensions of our being. That argument is not proof that mental can be reduced to the physical, nor does the threat of being dualistic disprove the reality of dualism. David Chalmers has an argument, or several arguments, for the irreducealbity of consciousness. Chalmers observes that consciousness escapes the reductive net and is not easily reduced to the physical by the assumptions reductionists make. It’s natural to assume that everything reduces to the physical, that consciousness supervenes upon the physical. No physical explanation can wholly account for the nature of consciousness. The argument is in what I call the “texture” or the “conscious nature” of consciousness itself. Chalmers argues that consciousness does not logically supervene upon the physical. The reductionists pull a biat and switch by demonstrating the reduction of brain function to the physical, obviously, then speaking as though they have demonstrated that consciousness is the same as brain function when in fact they have no such demonstration. The very nature of consciousness resists such a demonstration, yet the reductionist is often blind to this fact because they can’t stop identifying consciousness with brain function.
Chalmers full argument entails the theory of the supervenient but he also makes arguments without it. He says one can do it either way. I will avoid the complex and highly specialized issue in order to keep it simple; otherwise I am apt to become confused. He sets up the arguments so that they can be made and make sense without the supervenient analysis. The basic argument is grounded in the nature of consciousness which is seen in the so called “hard problem,” the inability to explain the nature of consciousness without losing the phenomena of consciousness. To illustrate the hard problem Chalmers constructs the notion of the philolophical zombie. Philosophical zombies differ from Hollywood zombies in that they are not mindless automatons who can’t think wondering about doing someone’s bidding. They are identical to us in every way so they cannot be identified as such externally. The only difference is they don’t have mental states or the “texture” of consciousness. They can think they can react logically and reason but they don’t have the mental experience going on inside. The zombie can’t feel the good morning but she can say “good morning” and in a way that implies that she means it. It doesn’t matter weather such zombies are actually possible or not. This is not a possible worlds argument its really more of an analogy that illustrates the distinction between the conscious and brain function. The upshot of the zombie thing is that one could have all the brain function to memic everything humans do, but still lack consciousness and that illustrates hat consciousness is not explained by brain function. If the organism with all the brain we have lacks the texture of consciousness then the two don’t share the same properties one is not dependent upon the other. Of course the opponent will argue that we are making more of consciousness than we should and that in imagining a world of such zombies we are inherently putting in the mental states just in ascribing to them our behaviors. The burden of proof is on them to prove that there is nothing more to the texture of consciousness than behavior.
The epistemic asymmetry of consciousness affords Chalmers a powerful argument. Conscious experience is a complete surprise given the relationship between mathematics and the rest of reality. That is to say, if not for our actual experience of consciousness we could never theorize or guess as to its’ existence just based upon scientific knowledge about brain function or the physical world. A world of philosophical zombies in which there was no experience of consciousness with all the scientific understanding we have could never come to realization that consciousness must exist for some beings somewhere.
From all the low-level facts about physical conﬁgurations and causation, we can in principle derive all sorts of high-level facts about macroscopic systems, their organization, and the causation among them. One could determine all the facts about biological function, and about human behavior and the brain mechanisms by which it is caused. But nothing in this vast causal story would lead one who had not experienced it directly to believe that there should be any consciousness. The very idea would be unreasonable; almost mystical, perhaps. It is true that the physical facts about the world might provide some indirect evidence for the existence of consciousness. For example, from these facts one could ascertain that there were a lot of organism’s that claimed to be conscious, and said they had mysterious subjective experiences. Still, this evidence would be quite inconclusive, and it might be most natural to draw an eliminative conclusion—that there was in fact no experience present in these creatures, just a lot of talk.
If consciousness was dependent upon the physical entirely as a shared property of the physical it would be deducible immediately by its relation to the physical. We should be able to deduce anything that is physical by understanding its physical break down. We can’t even get at a definition of consciousness that doesn’t exclude the mental qualia and reduce to brain function. That is not an explanation (though its taken for one by reductionts) it’s nothing more than losing the phenomena and re-labeling.
What Chalmers calls the most vivid argument against the logical supervienence of consciousness upon the physical is ‘the knowledge argument’ put forth by Jackson (1982) and Nagel (1974). The example he uses is that of a woman he dubs “Mary” who is the world expert on neurophysiology of color vision. She lives in an advanced time when science has all knowledge of the physical realm. Mary has been raised in a black and while room where she has never seen color. She understands everything there is to know about the physical processes of producing color but she does not know what red looks like. No amount of reasoning from the physical facts can tell her how red appears.
It follows that the facts about the subjective experience of color vision are not entailed by the physical facts. If they were, Mary could in principle come to know what it is like to see red on the basis of her knowledge of the physical facts. But she cannot. Perhaps Mary could come to know what it is like to see red by some indirect method, such as by manipulating her brain in the appropriate way. The point, however, is that the knowledge does not follow from the physical knowledge alone. Knowledge of all the physical facts will in principle allow Mary to derive all the facts about a system’s reactions, and its various abilities and cognitive capacities; but she will still be entirely in the dark about its experience of red.
He reinforces this idea by reference to Thomas Negal’s famous article of the 70’s “What is It Like to be a Bat?” All the physical knowledge about bats can’t tell us what it’s like to be one. That’s just multiplying examples at that point. We can’t know what it feels like to be a bat because we don’t have the consciousness of a bat. The texture of the experience is point in consciousness. The reductionists sometimes substitute brain function for the actual nature of the experience of consciousness. Until they get at that they can’t get at the hard problem. When they argue, as does Dennett in Consciousness Explained, discussing the theory of multiple drafts proposes that consciousness is just an epiphenomenal illusion that results from the process of editing perception by the brian does in perception, just a number of still photos shown in rapid succession become a moving picture. "You seem to be referring to a private, ineffable something or other in you mind's eye, a private shade of homogenous pink, but this is just how it seems to you, not how it is." There’s a lot that could be said to this point, for example see Latnz Miller’s devastating critique of Dennett’s book in Negations.  Yet the most to the point criticism that can be made is that it’s not about consciousness. This is about the function of the brain. That doesn’t do anything to get at the nature of consciousness itself. Tending to brain function in this way does not prove that consciousness arises out of brain function and has no larger reference as a basic property of nature. The only thing it does prove is that conscious awareness is accessed through brain function.
The issue of access is not the issue of causality. To say just exactly what is access and what is causing what, is hard to tell. It would be necessary to know that to resolve the argument either way. If there is a larger framework for consciousness than just being a side effect of chemicals in the head, such as a basic property or a principle of physical law or some such, then there must be some way in which what seems like an emergent property is actually connected to a larger principle. The fact that consciousness is communicated through brain chemistry is not a disproof. It may be the case that the evidence for irreducibility doesn’t prove it either. It would seem that irreducibility is a good reason to think that consciousness might be a basic property of nature. While at the same time the link between access and brain chemistry is not proof that mind reduces to brain or that consciousness is wholly a side effect of brain chemistry. The organizing effect of mind also adds another valid reason to suspect that consciousness could be a basic property.
 “Consciousness,” Stanford Encyclopedia of Philosophy. Archives pages. Website URL: http://www.science.uva.nl/~seop/archives/sum2004/entries/consciousness/#8.1 visited 1/22/11. Robert Van Gulick ed. and Copyright. (2004)
 John Searle “Why I am not a Property Dualist” originally from online document: URL: http://socrates.berkeley.edu/~jsearle/PropertydualismFNL.doc. from the Google Html version, propertydualismFNL.doc. November17, 2002 visited 12/6/10. URL: http://webcache.googleusercontent.com/search?q=cache:Y4Fr7m7rItQJ:socrates.berkeley.edu/~jsearle/PropertydualismFNL.doc+consciousness+is+not+reducible+to+brain+chemistry+but+is+a+basic+property+of+nature&cd=1&hl=en&ct=clnk&gl=us
 David Chalmers, The Conscious Mind: In Search of a theory. England, New York: Oxford University Press, 1996. on line version: http://www.scribd.com/doc/16574382/David-Chalmers-The-Conscious-Mind-Philosophy Scribd, David Chalmers, The Conscious Mind: In Search of a Theory of Conscious Experience, webstie Department of Philosophy, University of California at Santa Cruz, July 22 1995, visited 3/1/11 on line page numbers apply.
 Ibid, supervenient specialized philosophical term that refers to the necessary sharing of peripheries between two existents when one is a subset of the other.
 Ibid. 84
 ibid. 90
 in Chalmers, 90, originally in Philosophical Review, pp. 435-50
 Daniel C. Dennett, op cit, 329
 Lantz Miller, “the Hard Sell of Human Consciousness, and the recovery of consciousness in the nature of new language. part 1.” Negations: An Interdisciplinary Journal of Social Criticism. Issue 3, Winter 1998. On line copy: URL: http://negations.icaap.org/ (scroll down). For part 2 of Miller’s argument see the 2002 issue on the same site.