The central problem was and still is the relation between the materiality of the brain and the seemingly non-material stuff that constitutes consciousness or experience. We can say that there is an observable correlation between brain activity and certain kinds of experiences, and we can say that we're pretty certain that the material brain activity is causally related to experiential activity. But we really don't have the language and/or knowledge to express the materiality of conscious experience. My typing out words on the keyboard, my looking at this glowing computer screen, the birds twittering outside with a jet passing overhead, the mild temperature, the taste of coffee on my tongue, various ideas and memories flitting in and out of the forefront of consciousness, my saturating sense of dread at finishing up grading papers today, and so on comprise the experience of here-now that I'm having here-now. That experience is not experienced as synapses firing or the interaction of various bits of gray matter and electrical charges. The question is: how can matter have experiences, how can matter be conscious? This is the so-called "hard problem."
Jerry Fodor discusses Galen Strawson's latest book in "Headaches Have Themselves" in the London Review of Books. As Fodor notes, apart from standard Cartesian mind-body dualism, the main going answers to the questions posed in the paragraph above are either that consciousness is an illusion or that consciousness is an emergent feature of neural processes. Neither of these answers are adequate. So, Strawson comes up with another response. The premises of the argument are eminently reasonable, but the conclusion is to say the least rather trippy, to use a technical philosophical term. Here's Strawson's argument, as portrayed by Fodor:
There are three philosophical principles to which Strawson’s allegiance is unshakeable. The first is that the existence of consciousness (specifically, of conscious experience) is undeniable; that we are conscious is precisely what we know best. (To be sure, we can’t prove that we are conscious; but that is hardly surprising since there is no more secure premise from which such a proof could proceed.) Strawson’s second principle is a kind of monism: everything that there is is the same sort of stuff as such familiar things as tables, chairs and the bodies of animals. This, however, leaves a lot of options open since Strawson thinks that nothing much is known about that kind of stuff ‘as it is in itself’; at best science tells us only about its relational properties. What is foreclosed by Strawson’s monism is primarily the sort of ‘substance dualism’ that is frequently (but, he thinks, wrongly) attributed to Descartes...Whoa. Basic material things are not only the sources of consciousness, as standard materialism has it, but the loci of consciousness. Everything, since everything is material, is at least potentially the subject of experience.
...Strawson holds that there isn’t anything about matter in virtue of which conscious experience could arise from it; or that if there is, we have literally no idea what it could be. In particular, we can’t imagine any way of arranging small bits of unconscious stuff that would result in the consciousness of the larger bits of stuff of which they are the constituents. It’s not like liquids (Strawson’s favourite example of bona fide emergence) where we can see, more or less, how constituent molecules that aren’t liquid might be assembled to make larger things that are. How on earth, Strawson wonders, could anything of that sort explain the emergence of consciousness from matter? If it does, that’s a miracle; and Strawson doesn’t hold with those...
So, then, if everything is made of the same sort of stuff as tables and chairs (as per monism), and if at least some of the things made of that sort of stuff are conscious (there is no doubt that we are), and if there is no way of assembling stuff that isn’t conscious that produces stuff that is (there’s no emergence), it follows that the stuff that tables, chairs and the bodies of animals (and, indeed, everything else) is made of must itself be conscious. Strawson, having wrestled his angel to a draw, stands revealed as a panpsychist: basic things (protons, for example) are loci of conscious experience...
Nor, having swallowed this really enormous camel, does Strawson propose to strain at the gnats. Consider, for example: he thinks (quite rightly) that there are no experiences without subjects of experience; if there’s a pain, it must be somebody or something’s pain; somebody or something must be in it. What, then, could it be that has the experiences that panpsychists attribute to ultimate things? Nothing purely material, surely, since that would just raise the hard problem all over again. So maybe something immaterial? But monism is in force; since the constituents of tables and chairs are made of matter, so too is everything else. So, Strawson is strongly inclined to conclude, the subjects of the experiences that basic things have must be the experiences themselves. Part of the surcharge that we pay for panpsychism (not, after all, itself an immediately plausible ontology) is that we must give up on the commonsense distinction between the experience and the experiencer. At the basic level, headaches have themselves.
Now this conclusion (again, from reasonable premises) is so counter-intuitive that it's difficult to accept. How to deal with it? Fodor himself muses that,
Perhaps we can discover via work in artificial intelligence that when we jiggle a few bits of material things here and there - hardware and software - that something like human consciousness emerges from material stuff. Perhaps we could figure out the "laws" behind this jiggling, and perhaps we could even discover that these laws look very different from ones we're accustomed to in physics and chemistry. But we're then still faced with the basic laws of material stuff and why these laws should be this way rather than that. Further, they would simply explain the jiggling, not consciousness or experience itself. Perhaps, then the study of consciousness would be closer to ethics rather than physics in that certainty really applies to very little in ethics of anything other than a trivial nature.
Typical scientific explanations appeal to natural laws. Some natural laws are explained by appealing to others, but some aren’t; some of them are basic. So, roughly, the laws about molecules explain the laws about liquidity; and the laws about atoms explain the laws about molecules; and the laws about subatomic bits and pieces explain the laws about atoms . . . and so on down, but not so on down for ever. Eventually, we get to laws about whatever the smallest things are (or, perhaps, to laws about the fundamental structure of space-time); and there we simply stop. Basic laws can’t be explained; that’s what makes them basic. There isn’t a reason why they hold, they just do. Even if basic physical laws are true of everything, they don’t explain everything; in particular, they don’t explain why, of all the basic laws that there might have been, these are the ones there actually are. I don’t say that’s the right way to look at things, but it’s a perfectly respectable and traditional way. At a minimum, it seems that the various sciences form some sort of hierarchy, with physics (or whatever) at the bottom. That’s much as one might expect if the sort of view I’m discussing is at least approximately true.
Maybe, however, there’s something wrong with this view and we’ll finally have to do without it. Maybe the hard problem shows that not all basic laws are laws of physics. Maybe it shows that some of them are laws of emergence. If that’s so, then it’s not true after all that if Y emerges from X there must be something about X in virtue of which Y emerges from it. Rather, in some cases, there wouldn’t be any way of accounting for what emerges from what. Consciousness might emerge from matter because matter is the sort of stuff from which consciousness emerges. Full stop.
It would then have turned out that the hard problem is literally intractable, and that would be pretty shocking. The idea that the basic laws are the laws about the smallest things has been central to the ‘scientific world-view’ ever since there started to be one. On the other hand, as far as I can see, it’s not any sort of a priori truth. I suppose one can imagine a world where all the big things are made out of small things, and there are laws about the small things and there are laws about the big things, but some laws of the second kind don’t derive from any laws of the first kind. In that world, it might be a basic law that when you put the right sorts of neurons together in the right sorts of way, you get a subject of consciousness. There would be no explaining why you get a subject of consciousness when you put those neurons together that way; you just do and there’s the end of it. Perhaps Strawson would say that in such a world, emergence would be a miracle; but if it would, why isn’t every basic law a miracle by definition? I have my pride. I would prefer that the hard problem should turn out to be unsolvable if the alternative is that we’re all too dumb to solve it.