Even people who accept the Hard Problem as real still often make a distinction between cognition on one hand and qualitative subjective consciousness on the other. Cognition, presumably, is amenable to analysis in terms of information processing, and may in principle be performed perfectly well by a computer. It encompasses Chalmers's "easy problems". Subjective consciousness, or qualia, is the answer to "what is it like to see red?". Qualia is the spooky mysterious stuff that no purely informational or functional description of the brain will ever approach.
I would like either to clarify or eliminate the distinction. What exactly do we mean by "cognition"? When we speak of cognition in a computer, is it really the same thing that we are talking about when we speak of cognition in a human being? When we speak of "cognition" and "qualia", what are the distinguishing characteristics of each, such that we can be sure that some event in our minds is definitely an example of one and definitely not the other? The line between what we experience qualitatively and what we think analytically or symbolically is very hard, if not impossible, to draw. Even with the most purely qualitative impression, there is a troublesome second-orderliness - there is no gap at all between seeing red and knowing that you are seeing red.
Philosophers often talk about intentionality, which is the property of being about something. That is, something has intentionality to the extent that it is representational, or symbolic. Among the things that are often cited as being intentional are beliefs, desires, and propositions. People who talk about intentionality do not usually talk about qualia in the same breath, and vice versa. I believe that this is a mistake.
Recall that my zombie twin is an exact physical (and presumably cognitive) duplicate of me, but without any subjective phenomenal experience. It walks and talks like me, but is blank inside. There is nothing it is like for it to see red. Horgan and Tienson (2002) suggest an interesting thought experiment that turns the zombie thought experiment on its head. Imagine that I have a twin whose phenomenal experiencings (i.e. qualia) are identical to mine throughout both of our whole lives, but who is physically different, and in different circumstances (perhaps an alien life form, plugged into the Matrix, or having some kind of hallucination, or a proverbial brain in a vat). The question that screams out at me, given this scenario, but that Horgan and Tienson do not seem to ask (at least not in so many words) is this: to what extent could my phenomenal twin's cognitive life differ from my own? If the what-it-is-like to be it is, at each instant, identical to the what-it-is-like to be me, is it possible that it could have any thoughts, beliefs, or desires that were different from mine? Now, we may quibble over defining such things in terms of the external reality to which they "refer" (whatever that means), and decide on this basis that my phenomenal twin's thoughts are different than the corresponding thoughts in my mind, but this is sidestepping the really interesting question. Keeping the discussion confined to what is going on in our minds (that is, my mind and that of my phenomenal twin), is there any room at all for its cognition to be any different from mine? Charles Siewert (2011) makes similar points in his discussion of what he calls totally semantically clueless phenomenal duplicates.
Think of a cognitive task, as qualia-free as you can. Calculate, roughly, the velocity, in miles (or kilometers) per hour, of the earth as it travels through space around the sun. Okay. Now remember doing that. Besides the answer you calculated, how do you know you performed the calculation? You remember performing it. How do you know you remember performing it? Specifically, what was it like to perform it? There is an answer to that question, isn't there? You do not automatically clatter through your daily cognitive chores, with conclusions and decisions, facts and plans spewing forth from some black box while your experiential mind sees red and feels pain, and never the twain shall meet. You are aware, consciously, experientially, of your cognition. But what exactly is the qualitative nature of having an idea?
David Chalmers has asked whether you can experience a square without experiencing the individual lines which make it up. This question nicely underscores the blurriness of the distinction between qualia in the seeing red sense, and cognition in the symbolic processing sense. When you see a square, there is an immediate and unique sense of squareness in your mind which goes beyond your knowing about squares and your knowledge that the shape before you is an example of one. What is it like to see a circle? How about the famous Necker cube? When it flips for you, to what extent is that a qualitative event, and to what extent is it cognitive? Is it not clear that your "cognitive" interpretation of the cube (i.e. whether it sticks out down to the left or up to the right) has its own qualitative essence that outruns the simple pattern of black lines that you actually see? The classic duck/rabbit image is similar. You can't merely see; you always see as. What is it like to see the word "cat"? Wouldn't your what-it-is-likeness be different if you couldn't read English? Your cognitive parsing of your visual field is inseparable from the phenomenology of vision.
What is it like to have a train of thought at all? How do you know you think? What is it like to prove a theorem? What is it like to compose a poem? In particular, how do you know you have done so? Do you see it written in your head? If so, in what font? Do you hear it spoken? If so, in whose voice? You may be able to answer the font/voice questions, but only upon reflection - when pressed, you come up with an answer, but up to that point you simply perceived the poem in some terms whose qualitative aspects do not fit into the ordinary seeing/hearing categories.
There is a school of thought that holds that qualia are exclusively sensory - that any "qualia of thought" are qualitative only by inheritance. That is, we actually "hear" our thoughts in a particular auditory voice, or see things in our minds' eye. This is a stretch, and puts the cart before the horse. I, for one, don't think in anyone's voice. Moreover, any qualia of thought is not just tagging along in the form of certain charged emotional states that accompany certain kinds of thoughts. The qualia is right there, baked into the thoughts themselves, as such. The "purely" "cognitive" "content" is itself qualitative, not just the font it is written in, or the voice it assumes when it is spoken, or the hope or the fear that we attach to it.
Anything we experience directly, whether it is the kind of thing we usually associate with sensation and emotion or with dry reasoning and remembering, is qualitative: a song, a building, a memory, or a friend. By definition, all I ever experience is qualia. Even when I recall the driest, most seemingly qualia-free fact, there is still a palpable what-it-is-like to do so. To the extent that our cognition is manifest before us in the mind in the form of something grasped all at once, whether in the form of something which is obviously perceptual or something more abstract, it is qualitative. Otherwise, how would we be as directly aware of our thoughts as we are? How do you know you are thinking if you in no way express your thought physically (writing or speaking it)? A thought in your mind is simply, ineffably, manifestly before you, as a unitary whole, the object of experience as much as a red tomato is.
That we are aware of our thoughts at all in the way we are is no less spooky and mysterious than our seeing red. If you were a philosopher who was blind since birth, the "what is it like to see red?" argument for the existence of qualia would not have the same impact that it does on a sighted person. If you were also deaf, neither would "what is it like to hear middle C on a piano?". If you were a severe amnesiac in a sensory deprivation tank, assuming your mind were otherwise functioning normally, would you have any reason to worry about these mysterious qualia that other philosophers think about so much? I think you would, simply by virtue of noticing that you had a train of thought at all.
"What is it like to see red" or "what is it like to hear middle C on a piano" vividly illustrate the point of the Hard Problem to someone approaching these topics for the first time, but it is a mistake to stop at the redness of red. The redness of red is the gateway drug. Just because the existence of qualia is most starkly highlighted by giving examples that are particularly non-structured, and purely sensory, it is a mistake to think that the mystery they point to is confined to the non-structured and purely sensory. The paradigmatic examples of qualia are good for convincing people that don't have a solid basis for understanding everything that goes on in our heads. It is tempting, however, to think that we are at least on our way to having a basis for understanding what is going on in our heads when we think. My point is we don't have a good basis for understanding that either.
Just as qualia are not just the alphabet in which we write our thoughts, neither are they merely the raw material that is fed into our cognitive machinery by our senses. The qualia are still there in the experience as a whole after it has been digested, parsed, interpreted and filtered. Qualia run all the way down to the bottom of my mental processing, but all the way up to the top as well. We are not, to steal an image from David Chalmers, a cognitive machine bolted onto a qualitative base. Nor, as Daniel Dennett says (derisively), is qualitative consciousness a "magic spray" applied to the surface of otherwise "purely" cognitive thought. Each moment of consciousness has its own unique quale; new qualia are constantly being generated in our minds.
There are qualitative sensations that accompany particular, cognitively complex situations, but which are nevertheless no more reducible to "mere" information processing than seeing red is. Once, looking down from the rim of the Grand Canyon, I saw a hawk far below me but still quite high above the canyon floor, soaring in large, lazy circles. I was hit with a visceral sense of sheer volume - there is no other way to describe it. I felt the size of that canyon in three dimensions, or at least I had the distinct sense of feeling it, which for our purposes is the same thing. This was definitely something I felt, above and beyond my cognitively perceiving and comprehending intellectually the scene before me. At the same time, the feeling is one that is not a byproduct or reshuffling of sense data. After all, as a single human being I only occupy a certain small amount of space, and can have no direct sensual experience of a volume of space on the order of that of the Grand Canyon. Had I not experienced this feeling, I still would have seen the canyon and the hawk, and described both to friends back home. The feeling is ineffable - there is no way to convey it other than to get you to imagine the same scene and hope that the image in your mind engenders the same sensation in you that the actual scene did in me.
Nevertheless, the feeling that the scene engendered in me only happened because of my parsing the scene cognitively, interpreting the visual sensations that my retinas received, and understanding what I was looking at as I gazed out over the safety railing. The overall qualitative tone of a given situation depends crucially on our cognitive, symbolic interpretation of what is going on in that situation. Further, the individual elements of a scene before us have qualia of their own apart from the quale of the whole scene (e.g. there may be a red apple on a table in a room before us - it has the "red" quale, even though it is part of and contributes to the overall quale we are experiencing of the entire room at that particular moment).
There are some qualia, moreover, that are inherently inseparable from their "cognitive" interpretation, experiential phenomena that are especially resistant to attempts to divide them into pure seeing and seeing-as. In particular, as V. S. Ramachandran and Diane Rogers-Ramachandran pointed out (2009), we have stereo vision. When we look at objects near us with both eyes, we see depth. This is especially vivid when the phenomenon shows up where we don't expect it, as with View Masters, or lenticular photos (those images with the plastic ridges on them that are sometimes sold as bookmarks, or come free inside Cracker Jack boxes), or 3D movies. This effect is, to my satisfaction, unquestionably a quale. It is visceral. It is basic. You could not explain it to someone who did not experience it. At the same time, it is obviously an example of seeing-as, part of your cognitive parsing of a scene before you. One might possibly imagine some creature seeing red without any seeing-as, unable to interpret the redness conceptually in any way, but it is impossible to imagine seeing depth in the 3D way we do without understanding depth, without thereby automatically deriving information from that. To experience depth is to understand depth, and to infer something factual about what you are looking at, to model the scene in some conceptual, cognitively rich way.
What we know informs what we experience. I take it as pretty much self-evident that it is almost impossible to have a "pure" experience, stripped of any concepts we apply to that experience. Everything we experience is saturated with what we know, or think we know, what we expect, what we assume, etc. I have come to realize, however, that some name-brand philosophers, among them Fred Dretske, think that there is such a thing as pure perception, a phenomenal basis of experience, untainted by anything we might call cognition. Dretske claims that as much as our experiences are shaped by many layers of cognitive processing, there is some kernel of experience that is shared by us, and, say, a raccoon, viewing the same scene (ignoring differences in physiology, eyesight, etc.). This is simply not true, or at best, a mischaracterization of the situation. What I share with the raccoon is not an experience, but the raw bitmap comprised of the pattern of stimulation of the rods and cones on our retinas. This bitmap is fed into a lot of processing machinery, and in that sense contributes to an experience, but itself is far from constituting an experience.
The experience I have, and presumably that which the raccoon has, is made of seeing-as: seeing this blob as a hydrant, that one as a cloud, this splotch as the sun, that one as an object that I could touch, and that will probably persist through time. However experiences happen in minds, they are the result of lots of feedback loops at lots of different levels, all laden with associations and learned inferences, all stuff we might call cognition. There is no such thing as pure seeing, separated out from any seeing-as.
Through an act of willful intelligence, I could decide to concentrate only on those things in a scene before me that begin with the letters M, N, and G. Alternatively, I could choose to pay special attention to those things made of metal. In the same way, through willful, intelligent effort, I can try to derive some "pure experience" from the scene, and come up with something like a raw bitmap, perhaps for the purpose of painting a picture on a canvas of the scene. But even if this effort could possibly ever be 100% successful (I question this - could you really discard your understanding of object permanence?), this is further processing, more cognition, not less. For this reason, it is not quite right to say that I am starting with my cognition-soaked experience and working to get back to the "raw" experience, because that presumes there was such a thing originally to get back to.
For all but perhaps for the most basic qualia (a burn, a tickle, a pin prick), a pure experience, devoid of cognitive processing, is an abstraction, a conceit dreamed up by philosophers that has never actually been observed in the wild. It is a step in exactly the wrong direction, however, to thus conclude that knowledge and concepts can take full responsibility for experience, and that knowledge and concepts are among Chalmers's "easy" problems, solvable within reductive materialism. This step entails discarding qualia altogether, and concluding that experience is cognition all the way down. In contrast, experience is more accurately seen as qualia all the way up. Nevertheless, this is the step, more or less, that Dennett takes, and it is the step that adherents of Higher Order Thought take.
Higher Order Thought (HOT) theories, whose most prominent proponent over the years has been David Rosenthal, go more or less like this. We have sensory impressions, as of a red apple, but these are just lower-order thoughts (LOT), and thus not qualitatively conscious. It is only when we have an additional thought about that first, lower-order thought (this additional thought being the higher-order thought or HOT) that the whole thing becomes fully, qualitatively conscious. It is the HOT that assumes the role of "applying concepts" to the LOT.
I've never been entirely clear as to where the consciousness actually happens, in the LOT upon being reflected upon by the HOT, or in the HOT itself. Either way, the theory is not terribly satisfying. Once again, we have magic being snuck into the model under the guise of the never-quite-explained "aboutness" relation. Let us think like engineers and imagine a module called LOT and another module called HOT. Now let us connect the two with a bidirectional communications channel of any bandwidth we want - the sky's the limit. The sense impressions get initially fed into the LOT, then some signaling passes between the LOT and the HOT and we get consciousness. Couldn't we swap out either the LOT or the HOT and replace it with something else, like a dumb tape playback of a prior run of the experiment? In this case, the other module (the one we didn't swap out) would never know the difference, as long as the module we swapped out kept up its end of the conversation over the communications channel. What is it about that conversation, the signaling over the channel, that confers consciousness upon one of the modules on either end of the channel? And why is this any less mysterious than the original Hard Problem, of how consciousness arises from "signaling" over the channel provided by our sensory system? For a brief and funny take on this sort of objection to HOT theories, see the "overheard dialog" at the end of this.
There are some deep questions regarding the feedback loop between qualia and cognition, and the way our qualia and our concepts interact and influence each other on the fly. But HOT theories restate the question without answering it. The model they propose merely articulates the introspective intuition that there is a strange interdependence between what we usually think of as the experiential and what we usually think of as the cognitive. Articulating the observed intuition, however, does not answer any of the questions it presents. Worse, HOT theories assume that we can cleanly separate out qualia from cognition, and that this "aboutness" relation between them is straightforward and unproblematic, when these are exactly the assumptions we should be questioning. The really interesting question to ask when presented with the funny interdependence between cognition and qualia is where we ever got the idea that they were completely different kinds of things in the first place.
Many philosophers agree that in minds, qualitative consciousness and cognition are closely related, if not two ways of seeing the same thing, but make the mistake of concluding that qualia must therefore be merely information processing, which we think we understand pretty well. "Information" is a terribly impoverished word to describe the stuff we play with in our minds, even though much of what is in our minds may be seen as information, or as carrying information. Shoe-horning mind-stuff into the terms of information theory and information processing, however, is a homomorphism, a lossy projection. I suspect that there are no easy problems in the easy vs. Hard Problem sense. The way the mind processes information has a lot more in common with the way the mind sees red than it does with the way a computer processes information.
Once again, the computer beguiles us. Of course, we built it in our own image, so it is no surprise that it ends up being an idealized version of our own ideas of how our minds work. We understand computers down to the molecular level; there are no mysteries at all in computation. And clearly, computers know things, and they represent things. I can get some software that will allow me to map my entire house on the computer, to facilitate some home improvement projects I have in mind. And lo! My computer represents my couch, and seems to understand a lot about its physical characteristics, and it does so completely mechanically, and we can scrutinize what it is doing to achieve that understanding of it all the way down to the logic gate level. We are thus confident that we know exactly what is going on when we speak of knowledge, representation, information processing, and the like. There is nothing mysterious here, at least in the mechanics of what is going on.
Just because we understand computers, and computers seem to know, think, remember, infer, etc. we should not therefore think that now we understand those things. We do not study cave paintings as clinically accurate diagrams to learn about the human and animal physiology depicted therein. We study them to learn how these ancient people saw themselves and their world, to get inside their heads. The real insights to be gained into the mind from computers come from considering that this, this particular machine, is how we chose to idealize our own minds.
I can write "frozen peas" on a grocery list, and thereby put (mechanical) ink on (mechanical) paper. Later, when I pull out the list at the store, and it reminds me to put frozen peas in the cart, this physical artifact interacts with photons in a mechanical way. The photons then impinge upon my sensory system, and thus, in turn, my mind. So the paper and ink system represents frozen peas; it knew about them. Of course, most computers we use today are a bit more complex than the paper grocery list, but the essence is the same - there is the same level of knowledge, representation, information processing, etc. going on in each. We can say that in a sense, the list really does know about the peas, but not in a way that necessarily gives us any insight at all into how we know about peas.
There is no pure cognition in the mind, at least none that we are directly aware of. Over a century ago, philosophers did not separate cognition and qualia the way they do now. It was only in the early part of the 20th century, in the ascendance of behaviorism and the advent of Information Theory and Theory of Computation that we Anglophone philosophers started thinking that we are beginning to get a handle on "cognition" even if this qualia stuff still presented some problems. When some thinkers felt forced to acknowledge qualia, they grudgingly pushed cognition over a bit to allow qualia some space next to it in their conception of the mind, so the two could coexist; now they wonder how the two interact. The peaceful coexistence of cognition and qualia is an uneasy truce. Qualia can not be safely quarantined in the "sensation module", feeding informational inputs into some classically cognitive machine. We must radically recast our notions of cognition to allow for the possibility that cognition is qualia is cognition.