That there is a hard problem (in consciousness studies) is the first thesis, but not the main thesis, which is that there is naturalistic way out of the dualism that is inherent in accepting the hard problem. Thus he calls himself a naturalistic dualist.
Chapter 1 introduces the distinction between the “hard problem” and the “easy problems” of consciousness. The easy problems are those of explaining cognitive and behavioral functions such as discrimination, integration, and verbal report. The hard problem is that of explaining conscious experience. Where the easy problems are concerned, it suffices to explain how a function is performed, and to do this it suffices to specify an appropriate neural or computational mechanism. But where the hard problem is concerned, explaining cognitive and behavioral functions always leaves a further open question: why is the performance of these functions accompanied by experience? Because of this, the standard reductive methods of neuroscience and cognitive science that work for the easy problems do not work for the hard problem. I argue that this problem applies to any reductive explanation. In principle, these can explain only structure and function, and explaining conscious experience requires more than explaining structure and function.
If this is right, there can be no wholly reductive explanation of consciousness.
I go on to sketch an alternative nonreductive approach in which consciousness is taken as fundamental, and I sketch the outlines of a speculative theory of that sort.
(“Introduction,” Kindle Locations 251-259, my emphasis)
The Easy Problems
I suppose it is the brilliance of Chalmers’ argument for the reality of the Hard Problem that he disposes so easily, not to say cavalierly, of all the really very hard problems the neuroscientists and their philosopher camp followers continue to grapple with. He does this by conceding the ground to the materialists. All that, he says, is perfectly doable if not yet done — we can explain the reportability of mental states in principle if not quite yet. Here’s why:
There is no real issue about whether these phenomena can be explained scientifically. All of them are straightforwardly vulnerable to explanation in terms of computational or neural mechanisms. To explain access and reportability, for example, we need only specify the mechanism by which information about internal states is retrieved and made available for verbal report. To explain the integration of information, we need only exhibit mechanisms by which information is brought together and exploited by later processes. For an account of sleep and wakefulness, an appropriate neurophysiological account of the processes responsible for organisms’ contrasting behavior in those states will suffice. In each case, an appropriate cognitive or neurophysiological model can clearly do the explanatory work. (Chapter 1.1, Kindle Locations 569-574).
The Hard Problem
Chalmers develops his claims about the easy problems in the next two or three pages while at the same time arguing for the different status altogether for the hard problem — that, unlike those, it, consciousness, can have no functional, mechanical, reductive explanation. As I read these pages, I am constantly called to object to the claims as to the mechanistic explainability of what he is calling the easy problems. This is an area in which I have read contrary thinkers rather widely, and I suspect many others have as well. But it is disarming to see that at the same time he is headed for a position with which I am quite in agreement, as would all my fellow camp followers be, that consciousness itself can surely not be explained mechanically. Thus:
When it comes to conscious experience, this sort of explanation fails. What makes the hard problem hard and almost unique is that it goes beyond problems about the performance of functions. To see this, note that even when we have explained the performance of all the cognitive and behavioral functions in the vicinity of experience—perceptual discrimination, categorization, internal access, verbal report—a further unanswered question may remain: why is the performance of these functions accompanied by experience? A simple explanation of the functions leaves this question open. (Chapter 1.3, Kindle Locations 635-639).
The Even Harder Problem
On this surface of it, this makes Chalmers some modern sort of Cartesian. We have on the one hand an automaton or zombie (the new term of art) and on the other hand ourselves in the a/z body with our consciousness. The two aspects of us don’t appear to have any way to influence each other causally, and yet they do. How can this be? The answer is Chalmers’ real thesis, what he calls naturalistic dualism.
If the world were to accept Chalmers’ thesis, it would have a resolution of the mind-body problem. I suspect that is the Holy Grail of philosophy and that will explain quite nicely why he spends the rest of his book, this a second one, in arguing for it. Here’s how it goes.
We have seen that there are systematic reasons why the usual methods of cognitive science and neuroscience fail to account for conscious experience. These are simply the wrong sort of methods. Nothing that they give to us can yield an explanation. To account for conscious experience, we need an extra ingredient in the explanation. This makes for a challenge to those who are serious about the hard problem of consciousness: what is your extra ingredient, and why should that account for conscious experience? (Chapter 1.5, Kindle Locations 744-748).
Descartes’ extra ingredient was the pineal gland. In section five Chalmers looks at several perhaps equally far out offerings, rejecting them all for the same reasons, actually, that he rejected some explanations closer in to the usual mechanistics of neuroscience in section four. Typically: “This is useful for many purposes, but it tells us nothing about why there should be experience in the first place..” Then in section five he rejects, for the same basic reason, several more options offered, like the Hameroff QM microtubule hypothesis. I am not so sure that these are essentially different from those he rejects in section four, but the bottom line is the same line of argument. And that does seem like a good argument to me.
And this brings Chalmers around to his main purpose, which is to offer his own explanatory thesis. This is the classic argumentive procedure — first create a need in your reader for an explanation, as by rejecting all the others that have been offered, then bring on your own hypothesis and make it seem reasonable.
At this point some are tempted to give up, holding that we will never have a theory of conscious experience. McGinn (1989), for example, argues that the problem is too hard for our limited minds; we are “cognitively closed” with respect to the phenomenon. Others have argued that conscious experience lies outside the domain of scientific theory altogether.
I think this pessimism is premature. This is not the place to give up; it is the place where things get interesting. When simple methods of explanation are ruled out, we need to investigate the alternatives. Given that reductive explanation fails, nonreductive explanation is the natural choice. (Chapter 1.6, Kindle Locations 809-813).
What he offers is that we take experience as non-explainable, a simple given of the universe, like electric charge or matter itself.
Of course, by taking experience as fundamental, there is a sense in which this approach does not tell us why there is experience in the first place, but this is the same for any fundamental theory. Nothing in physics tells us why there is matter in the first place, but we do not count this against theories of matter. Certain features of the world need to be taken as fundamental by any scientific theory. A theory of matter can still explain all sorts of facts about matter by showing how they are consequences of the basic laws. The same goes for a theory of experience. (Chapter 1.6, Kindle Locations 838-842).
The problem, of course, is still the same old one — how, then, do we imagine or understand that the one fundamental property somehow interacts with what we take to be another one that is fundamentally different, like the matter and functional processes of our usual reductive explanation? Chalmers’ answer is to postulate “bridging principles” that will take care of the interaction. I think principles themselves are rather like laws, as in laws of nature. They only exist by virtue of our having discovered the behavior that they encapsulate and predict in what we take it does exist in a more substantial manner.
Now Chalmers knows these principles have not yet been discovered, so he offers a program for discovering them and uses his philosophy to suggest some guidelines for looking for them and something about what they might look like. There exists as yet no body of scientific study aimed at finding the principles, and, of course, no data of experiment to debate the meaning of. We are in the realm of thought, but I find it an interesting area for a little more reflection. Consider what he says immediately after the paragraph I quoted just above:
This position qualifies as a variety of dualism as it postulates basic properties over and above the properties invoked by physics. But it is an innocent version of dualism, entirely compatible with the scientific view of the world. Nothing in this approach contradicts anything in physical theory; we simply need to add further bridging principles to explain how experience arises from physical processes. There is nothing particularly spiritual or mystical about this theory—its overall shape is like that of a physical theory, with a few fundamental entities connected by fundamental laws. It expands the ontology slightly, to be sure, but Maxwell did the same thing. Indeed, the overall structure of this position is entirely naturalistic, allowing both that the universe ultimately comes down to a network of basic entities obeying simple laws and that there eventually may be a theory of consciousness cast in terms of such laws. If the position is to have a name, naturalistic dualism is a good choice. (My emphasis apart from the last. Chapter 1.6, Kindle Locations 842-849).
If he is right that merely adding or discovering further principles of explanation that would link the material and conscious worlds of being would be entirely compatible with the scientific view of the world, then there is at present no contradiction either. Meaning no contradiction for science to accept, say, the paranormal, as a simple and as yet unexplained aspect of the world we experience — awaiting the needed bridging principles. Chalmers by no means says this (he says, “There is nothing particularly spiritual or mystical about this theory—its overall shape is like that of a physical theory, with a few fundamental entities connected by fundamental laws.”) but I personally think it follows from his neat detachment of conscious experience from material brain processes.
