Laakso (1997) criticizes me for sliding between being a functionalist and an identity theorist with respect to consciousness. However, he basis his claims on an incomplete understanding of functionalism and his arguments confuse identity with necessary and sufficient conditions. Here I outline these errors as well as state as clearly as I can that I am an identity theorist through and through.
2. As I have explained in some detail elsewhere, functionalism does not always presume a particular ontology, nor is what counts as a functionalist explanation entirely clear (see Hardcastle, 1996a; 1996b). But for simplicity's sake (and going against what I actually hold), let us assume a metaphysical functionalism: the view that mental states (or whatever) are exhaustively captured by their relationships with other mental states, inputs, and outputs. That is, mental states are fundamentally relational and their essence is determined by their functional or causal connections with other states or events. Laakso wants to claim that neural patterns of activation are such functional items. I disagree. At the least, much more work must go into proving that point.
3. I do agree that we do not need to refer to the individual neurons when explaining the dynamical patterns we find across large areas of cortex. Laakso is correct in his "charge" that I "[insist] that thinking systems have properties that are not type-reducible to physical properties" (para. 3). But more is required before one uniquely identifies a functionalist approach: supervenience theorists, phenomenologists, and even dualists and identity theorists can believe that.
4. What Laakso fails to see, I think, is that I believe that the neural firing patterns I discuss are importantly brain-like. From my perspective, talking about a brain's neural firing patterns is one way of talking about a brain. Talking about the interactions of the individual neurons is another way of talking about maybe the same brain. Talking about the influx and efflux of ions across cell membranes is yet another way. These are merely different levels of description of one and the same object. At this stage in the game, it is simply premature to make definitive claims about what properties are needed for consciousness -- the patterns, the individual neurons, the ions, and so forth. I am placing my bets on the patterns as the level at which we will make the most progress, but I certainly am not asserting that, as a result of my bet, we should be functionalist about the patterns.
5. In short, I am an identity theorist through and through. I am interested in locating consciousness within our brains' processing stream. I am not at all interested in making general claims about consciousness across all possible forms of cognitive systems in the universe, for that has always struck me as a perverse philosopher's game. I would happily plead guilty to the charge of animal chauvinist, but I do not plead guilty for trying to extend my ideas beyond what we believe to be the case about mammals here on Earth. In sum, I do not "equivocate" or "[change my] mind" (para. 6), nor do I embrace a "contradiction" (para. 9). I simply deny that a system dynamical approach means that I have to be a metaphysical functionalist.
6. Keeping the distinction between functionalism and identity theories clear is important because it can prevent other muddles. For example, Laakso writes that "absent qualia ... are quite possible on the premise that any kind of functionalism is true" (para. 7). This is straightforwardly false. Take the sort of functionalism Laakso wants to saddle me with: good old-fashioned metaphysical functionalism. If mental states are essentially relational, then qualia are relational, too. That means that any time you find the appropriate causal structure, then you find qualia. It might be counter-intuitive to hold that qualia appear whenever there is an appropriate pattern of activation -- as Laakso says, "the dynamic firing patterns of the neurons in our brains could quite easily be replicated in computer simulations, but we have no reason to suppose that the computers would thereby be endowed with consciousness" (para. 4) -- but if one is a metaphysical functionalist, then simulating the relevant patterns equals duplicating the mental state. The computer would be conscious for the same reason we are: we both instantiate the appropriate causal relations. That would be all the "reason" a functionalist would require.
7. A similar (though more trivial) line of reasoning works for the identity theorist. If we duplicate whatever is identical to consciousness, then we get consciousness. It is only when one runs functionalism and an identity theory together (or fuzz either of them up) that the claim that absent qualia are possible seems reasonable.
8. The important question, of course, is what to duplicate in order to duplicate consciousness. Unfortunately, being an identity theorist does not mean that I know what the identity conditions for consciousness are. And here we find Laakso's second muddle: discovering the necessary and sufficient conditions for something is not the same thing as discovering its identity conditions. Laakso apparently believes that finding a particular neurophysiological implementation to be necessary for being in some psychological state plus finding that same implementation to be sufficient for the psychological state is equivalent to saying that the implementation and the mental state are identical (para. 5). But it is easy to see that this view is wrong. Proponents of a pre-established harmony would say that some neural state is necessary and sufficient for being in some conscious state, but they wouldn't claim that the neural state is the conscious state.
9. Furthermore, despite his assertions to the contrary (para. 5), nowhere do I make any claims about what is necessary or sufficient for consciousness anyway. As much as philosophers like to talk about such things, we simply don't know enough about how the mind/brain works to discuss such sureties. In fact, this is the reason why I called the book Locating Consciousness instead of Explaining Consciousness: we know enough to be able to locate consciousness physically in the brain and to be able to articulate some things about what these areas are doing for us psychologically, or so I argue, but we cannot say exactly what it is about these areas that gives us consciousness. I present a start, not the final solution.
10. Finally, Laakso takes me to task for apparently not fulfilling my promise to show that "conscious experience is needed to account for our behavior" (1996, p. 44). But again, he seems to miss the philosophical boat in important ways. This seems to me to be a straightforward empirical claim about what is required for psychological explanations. Consequently, it is a mystery to me why Laakso looks to chapter 7, the chapter in which I discuss in some detail the philosophical points I recapitulate above (further details can be found in Hardcastle, 1996c), as the place I was supposed to answer my personal charge.
11. Chapters 2, 4, and 5 in Locating Consciousness are devoted to explaining how we require consciousness in order to explain the distinction between implicit and explicit priming, the psychological products of several brain lesions, infant development, and some animal behavior. These are claims that will rise or fall with the empirical data, and I certainly would be foolish to believe that I am entirely correct in my analysis of where the phenomena of consciousness fit into our processing streams. However, the philosophical claim that absent qualia are impossible for adherents to my brand of multi-level theorizing -- whether you see this as functionalism or identity-ism -- is entirely orthogonal to the issue. To claim that I did not meet my goal one would have to argue that I am mistaken in my interpretation of the data or that there are data which contraindicate my conclusions.
12. The lesson I think we can learn from Laakso's review is that it is as important to keep the philosophy straight when theorizing about the mind as it is to keep conceptual issues separate from empirical ones. How to understand the relationship between the mind and the body and how to understand the relationship between consciousness and the rest of our cognitive economy are difficult questions indeed, and it behooves us to be as accurate and precise as possible, even when it is not that means we will not be very accurate or precise at all!
Hardcastle, V.G. (1995). Locating Consciousness. Amsterdam & Philadelphia: John Benjamins Press.
Hardcastle, V.G. (1996a). How to Build a Theory in Cognitive Science. Albany, New York: SUNY Press.
Hardcastle, V.G. (1996b). A Functionalist's Response to the Problem of Absent Qualia: More Discussion. Journal of Consciousness Studies, 3, 357-373.
Hardcastle, V.G. (1996c). Computationalism. Synthese, 105, 303-317.
Hardcastle, V.G. (1996d). Precis of: Locating Consciousness. PSYCOLOQUY 7(33) locating.consciousness.1.hardcastle.
Laakso, A. (1996). Has Hardcastle Located Consciousness? Book Review of Hardcastle on Locating Consciousness. PSYCOLOQUY 7(42) locating.consciousness.2.laakso.