Consciousness

Re. blueness: Mitchell is talking about qualia. Google the hard problem of consciousness.

Furthermore the brain fakes much of the data, giving the perception of colour vision, for example, in regions of the visual field where no ability to discriminate colour exists,

Just a note - I don't disagree with your point; but the claim that we can't discriminate color in our peripheral vision is simply false. I've done some informal experiments with this, because I was puzzled that textbooks say that our peripheral vision is primarily due to rods, which can't detect color; yet I see color in my peripheral vision.

If I stand with my nose and forehead pressed against the wall, holding a stack of shuffled yellow and red sheets of origami paper behind my back, close my eyes, and then hold one sheet up in each of my outstretched arms, and open my eyes, so that the sheets are each 90 degrees out from my central vision and I see them both at the same time, I can distinguish the two colors 100% of the time.

There's a serious problem with resolution; but color doesn't seem to be affected at all in any way that I can detect by central vs. peripheral vision.

It seems you agree that colors, the flow of time, meanings, and the unity of experience all appear to be there. The general import of your remarks is that reality isn't actually like that, it only appears to be like that. You state how things are, and then you state what's happening in the brain in order to create certain appearances. Color and time are external appearances, meaning and unity are internal appearances.

Some of what you say about the imperfections of conscious representations is not an issue for me. The fidelity of the mapping between external states and conscious states only has an incidental bearing on the nature of the conscious states themselves. Whether color is sometimes hallucinated is not the issue. Whether a color is nothing but an equivalence class is the issue.

In this regard I have observed a number of positions taken. Some people are at the stage of saying, color is a neural classification and I don't see any further problem. Some people say that color is how it "feels" to make such a classification. Since Dennett takes care to deny that there is anything that is actually colored, even in the mind, and that there are only words, dispositions to classify, and so forth, he arguably wishes to deny even that there is a "color feeling", though it's hard to be sure.

My position is very simple. All these things (color, time, meaning, unity) exist in consciousness; which means that they exist in at least one part of reality. The elements and the modes of combination offered by today's scientific ontology do not suffice to generate them. Therefore, today's scientific ontology is wrong, incomplete, however you want to put it.

So if we are to have a discussion, you need to say less about the imperfections of consciousness as a medium of representation, and more about the medium itself. Do you agree that color, time, meaning, unity exist in consciousness? If so, can you identify the physical or computational property which supposedly corresponds to, or is identical to, "appearing to experience" each of these various phenomena?

I thought of linking, but I wanted a fresh start, something self-contained. It's a debatable choice. What I really wish is that when I posted this two days ago, I'd thought of creating in advance a thread for each major question. It will be difficult to migrate the discussion there now, but I would like to try.

Responding briefly:

1) I think "where is color?" and "where is chess?" are just different sorts of questions. The latter is an instance of "where is meaning?" or "where is computation?". Because meaning and computation can be imputed to symbols and artefacts by convention, the where-is-chess discussion needs to keep the human original in view as well. A systematic answer should first say where is chess when humans play each other. Then we can talk about chess computers playing each other, and whether that situation contains chess only by convention, or intrinsically, or whether machine chess is a mixture of intrinsic and attributed meaning and computation.

2) If you wish to speak of there being symbols in the brain, again, you have to take a position on computation and meaning. Then, if you've managed to identify an actual physical thing or property which you think can be called a symbol, then you need to explain how to get color out of that particular physical thing.

By life I assume you mean replicators.

Turing computability is not much of an issue for me. It amounts to asking whether the state transitions in an entity can be abstractly mimicked by the state transitions in a Turing machine. For everything in your list, the answer ought to be, yes it can.

However, that is a very limited and abstract resemblance. You could represent the mood of a person, changing across time, with a binary string. But to say that their sequence of moods is a binary string is descriptive rather than definitional.

It sounds like you do want to reduce all mental or conscious phenomena to strictly computational properties. Not just to say that the mind has certain computational properties, but that it has nothing but such properties; that the very definition of a mind is the possession of certain computational properties or capacities.

To do this, first you will need to provide an objective criterion for the attribution of computational properties, such as states. You can chop up a physical state space in many ways, so as to define "high-level" states; which such clustering of physical states, out of all the possibilities, is the one that you will use, and why? Then, you may need to explain what is computational about these states. If you want to say that they have representational content, for example, you will need to say what they are representing and on what basis you attribute this meaning to them. And finally, if you also wish to say that sensory qualities like colors are nothing but computational properties, you will need to say which computational properties, and something about why they "feel" that way.

All of this assumes that you agree that color and meaning do exist in experience. If they are there, they need to be explained. If they do not need to be explained, it can only be because they are not there.

I imagine you would expect all those; one would simply not expect the subjective experience of the colour blue.

EDIT: commenters below have caused me to think better of my impatient tone below. Please imagine strikethrough through

In the absence of any replies[*] from you more than 24 hours after you posted the original article, which I think is a little rude and I hope is accounted for by unexpected real-world constraints, I shall resort to further attempts to anticipate and forestall possible replies.

"I don't know" isn't an acceptable answer either. The question isn't "what will happen in such a Universe", it's "at what point to you balk at the possibility". You balk before the end of "it could be just like our Universe" and after the beginning (which is, say, the game of Life) so you have to be able to identify a balk point somewhere on the scale.

EDIT: would appreciate downvote explanation - thanks! EDIT: [*] to any comments in this thread, not just to my comments - thanks Alicorn for prompting me to clarify

I wonder if "How does neurons firing cause us to have a subjective experience?" might be unintentionally begging Mitchell_Porter's question. Best I can tell, neurons firing is having a subjective experience, as you more or less say right afterwards.

My problem is I don't see how you can avoid a "that's how an algorithm feels from the inside" explanation somewhere down the line. Even if you create some theory that purports to account for the (say) mysterious redness of red, isn't there still a gap to bridge between that account and whatever your subjective perception - your feeling - of red is? I'm confused as to what an 'explanation' for the mysterious redness of red would even look like.

I would like to see a better reply to this comment. Why doesn't this address the problem of Color from the OP? Is it because the jump from wavelength to the label of "Blue" hasn't been defined?

From the OP:

So if you intend to tell me that reality consists solely of physics, mathematics, or computation, you need to tell me where the colors are.

I'm not trying to be tricksy or smart. I am trying to understand the question and why the above isn't an answer. In essence, all confusion would be lifted if you replaced the words "red" and "green" with something else in the following paragraph:

Whether your physics consists of fields and particles in space, or [...] whatever - I don't see anything red or green there, and yet I do see it right now, here in reality.

As in,

Whether your physics consists of fields and particles in space, or [...] whatever - I don't see anything {word A} or {word B} there, and yet I do see {word C} right now, here in reality.

Words A, B, and C all belong to some category and that category is not "seen" in physics but is "seen" in reality. Thomblake is trying to use "wavelengths":

Whether your physics consists of fields and particles in space, or [...] whatever - I don't see [any wavelengths] there, and yet I do see [wavelengths] right now, here in reality.

This makes no sense to me, so something must be wrong in my translations. What is it?

There is also the fact that what we describe as "redness" is purely by virtue or our anatomy and the ranges at which our eyes' structure receives the light that is then interpreted by our brain as red or blue.

Red, or Blue are just words that we used to describe a state that exists in the universe. What would happen to these colors if our eyes were made of a type of structure that picked up EM radiation all the way from gamma-rays to long-wavelength radio waves?

What "color" would we think something in the Microwave spectrum was? What about the X-Ray Colored objects?

FYI: Unlike electronic devices, your visual system doesn't detect absolute color, hence these illusions.

Since we can presumably generate the appropriate signals in the optic nerve from scratch if we choose, light and its wavelength have nothing whatsoever to do with color.

Um, even I would have to judge that saying anything whatsoever about apple trees, in answer to the question Mitchell is asking, is blatantly running away from the scary and hence interesting part of the problem, which will concern itself solely with matters in the interior part of the skull. Anyone talking about apple trees is running away from their ignorance of the inside of the skull, and finding something they understand better to talk about. Reductionist or not, I cannot defend that.

Your first line ("What dire consequences should we expect if we do, in fact, deny that there is anything that is blue ?") is an appeal to the consequences of a belief about a matter of fact, and therefore irrelevant.

What remains without that is good.

Do you think it will ever be possible to say whether chess qualia exist, and what they are like? Will we ever understand what it is like to be a bat?

Being a bat shouldn't be incomprehensible (and in fact Nagel makes some progress in his essay). You still have a body and a sensorium, they're just different. Getting your sense of space by yelling at the world and listening to the echoes - it's weird, but it's not beyond imagining. The absence of higher cognition might be the hardest thing for a human to relate to, but everyone has experienced some form of mindless behavior in themselves, dominated by sensation, emotion, and physical activity. You just have to imagine being like that all the time.

Being a quantum holist[*] and all that, when it comes to consciousness, I don't believe in qualia for Deep Blue because I don't think consciousness arises in that way. If it's like something to be a rock, then maybe the separate little islands of silicon and metal making up Deep Blue's processors still had that. But I'm agnostic regarding how to speak about the being of the very simplest things, and whether it should be regarded as lying on a continuum with the being of conscious beings.

Anyway, I answer both your questions yes, and I think other people may as well be optimistic too, even if they have a different theoretical approach. We should expect that it will all make sense one day.

[*] ETA: What I mean by this is the hypothesis that quantum entanglement creates local wholes, that these are the fundamental entities in nature, and that the individual consciousness inhabits a big one of these. So it's a brain-as-quantum-computer hypothesis, with an ontological twist thrown in.

I don't think your question is well represented by the phrase "where is computation".

Let me ask whether you would agree that a computer executing a program can be said to be a computer executing a program. Your argument would suggest not, because you could attribute various other computations to various parts of the computer's hardware.

For example, consider a program that repeatedly increments the value in a register. Now we could alternatively focus on just the lowest bit of the register and see a program that repeatedly complements that bit. Which is right? Or perhaps we can see it as a program that counts through all the even numbers by interpreting the register bits as being concatenated with a 0. There is a famous argument that we can in fact interpret this counting program as enumerating the states of any arbitrarily complex computation.

Chalmers in the previous link aims to resolve the ambiguity by certain rules; basically some interpretations count and some don't. And maybe there is an unresolved ambiguity in the end. But in practice it seems likely that we could take brain activity and create a neural network simulation which runs accurately and produces the same behavioral outputs as the brain; the same speech, the same movements. At least, if you were to deny this possibility, that would be interesting.

In summary, although one can theoretically map any computation to any physical system; for a system like we believe the brain to be, with its simultaneous complexity and organizational unity, it seems likely that one could come up with a computational program that would capture the brain's behavior, claim to have qualia, and pose the same hard questions about where the color blue lay among the electronic circuits.

I agree with your interpretation of our current physical and experiential evidence. I believe the perceived dualistic problem arises from imperfections in our current modeling of brain states and control of our own. We cannot easily simulate experiential brain states, reconfigure our own brains to match, and try them out ourselves. We cannot make adjustments of these states on a continuum that would allow us to say physical state A corresponds exactly to experience B and here's the math. We cannot create experience on a machine and have it tell us that it is experiencing. Without internal access to our source-code, our experiences come into our consciousness fully formed and appear magical.

That being said, the blunt tools we do have--descriptions of other's experiences, drugs, brain stimulation, fMRI, and psychophysics--do seem to indicate that experience follows directly from physical states of the brain without the need for a dualist explanation. Perhaps the problem will dissolve itself once uploading is possible and individual experiences are more tradeable and malleable.

Do you disagree with any of this?

I certainly think about things differently:

1'. There is a world, which includes subjective experiences, and (presumably) things which are not subjective experiences.

2'. All information I have about the world, including the subjective experiences of other people, comes through my subjective experiences.

3'. I possess mathematical/physical theories which appear adequate to describe much of the posited world to varying degrees, but which do not refer to subjective experiences.

4'. Subjective experiences are causally consequential; they are affected by sensation and they affect behavior, among other things.

5'. The way the world actually is and the way the world actually works is a little more complicated than any theory I currently possess.

However, I do insist that something is red.

Why?

That aside: Red is something that arises out of things that are not themselves red. Right now I'm wearing a sweater, which is made out of things that are not themselves sweaters (plastic, cotton with a little nylon and spandex; or on a higher level, buttons, sleeves, etc.) A sweater came into existence when the sleeves were sewn onto the rest of it (or however it was pieced together); no particles, however, came into existence. My sweater just is a spatial relationship between a vague set of particles (I say "vague" because it could lose a button and still be a sweater, but unlike a piece of lint, the button is really part of the sweater). If I put it through the shredder, no particles would be destroyed, but it would not be a sweater.

My sweater is also red. When I look at it, I experience the impression of looking at a red object. No particles come into existence when I start to have this experience, but they do arrange differently. Some of the ways my brain can be arranged are such that when they are instantiated, I experience the impression of looking at something red - such as the ones that come into play when I look at my sweater in light good enough for me to have color vision. If I put my brain through the shredder, not only would I die, but I'd also no longer be experiencing the impression of looking at my sweater.

Why does the fact that individual particles are not red prompt, for you, the question of what is red, but the fact that individual particles are not sweaters does not prompt the question of what sweaters are?

Where is lesswrong.com? "On the internet" would be the naive answer, but there's no part of the internet we could naively recognize as being lesswrong.com. A bunch of electrical impulses get interpreted as ones and zeroes which get translated in a certain language, which converts them into another language (English), which each mind interacting with the site translates in its own way. At the base level, before minds get involved, there's nothing more complex that a bunch of magnets and electric signals and some servers and so on (I'm not a computer person, so cut me some slack on the details). Yet, out of all of that emerges your post, this comment, and so on.

I know that it is in principle possible to understand how all of this comes together, but I also know that I do not in fact understand it. If I were really to look at how complex this site is - down to the level of the chemist who makes the fertilizer to supply the farmer who feeds the truck driver who delivers the petroleum that gets refined into the plastic that makes the keyboard of the engineer who maintains the power plant that keeps the server running - I have absolutely no idea what's going on, and probably never will even if I devoted my entire life to understanding how this website comes together. In fact, I have good reason to believe there are parts of what's going on that I don't even know are parts of what are going on - I don't even understand the basic underlying structure at a complete level. But if a bunch of people were really dedicated to it, they could probably figure it out, so that by asking the group of them, you could figure out what you needed to know about how the site works; in other words, it is in principle understandable, even if no one understands it in its entirety.

There is thus nothing particularly problematic about saying, "So, I don't get how this whole consciousness thing works, but there's probably no magic involved," just as there's no magic (excepting EY's magic) involved in putting this site together. Saying, "I can't naively figure out how some extremely complicated system works, therefore, the answer is: magic!" is simply not a reasonable solution. It is possible that there is something more going on in the brain that we can currently understand, but it seems exceedingly unlikely that it is in principle un-understandable.

Suppose it turned out that the part of the brain devoted to experiencing (or processing) the color red actually was red, and similarly for the other colors. Would this explain anything?

Wouldn't we then wonder why the part of the brain devoted to smelling flowers did not smell like flowers, and the part for smelling sewage didn't stink?

Would we wonder why the part of the brain for hearing high pitches didn't sound like a high pitch? Why the part which feels a punch in the nose doesn't actually reach out and punch us in the nose when we lean close?

I can't help feeling that this line of questioning is bizarre and unproductive.

Red is in your mind. It's a sensation. It's what it feels like inside when you're looking at something you call red. Nothing is actually red, it's just a verbal symbol you assign to a particular inner sensation.

I will very, very happily grant that we do not have a good explanation for how the brain creates such subjective, inner sensations. Notice I wrote "how" and not "why".

There is no such thing as a zombie as they are usually defined, because every time you make a brain, so long as it is physically indistinguishable from a regular brain, it's going to be conscious. That's what happens when you make a brain that way (you can try it out by having a child). On the other hand, if we allow the definition of a zombie to be changed just a little bit, so that it includes unconscious things that are merely behaviorally indistinguishable from conscious people, then I see no problem at all with that kind of zombie. But their insides would be physically, detectably different. Their brains would not work the same way as ours. If they did, then they would be conscious.

Regular brains produce private, inner sensation, just as surely as the sun produces radiation. The right question is not why should this be so?, but how does it do it? And I grant that this is an unanswered question. Heterophenomenology is just fine as far as it goes, but it doesn't go this far. All that stuff about only asking why an agent verbalizes or believes that it sees red is profoundly unsatisfying as an explanation for redness, and for a very good reason. It's like behaviorism in psychology - maybe fine for some purposes, but inherently limited, in the negative sense. It ignores the inner sensation that we all know is there.

Now, that's no reason to suppose that the red sensation is not explainable or reducible. We just don't understand the brain well enough yet, so we'll just have to keep thinking about it and wait until we do.

Did anyone else notice the similarity of Mitchell's arguments in this post, and the one in his comment to one of my posts? Here he says that there is no color in a purely physical description of a mind, and in his comment to my post he said that there is no utility function in a purely physical description of a mind.

I think this argument actually works better here (with color), because my counter-argument to his comment doesn't work. What I said was that in principle we know how to go from a utility function to a physical description of an object (by creating an AI) and so in principle we also know how to go from a physical description to a utility function.

Here, we don't know how to go from a color to a physical description of a mind that can experience that color, nor can we tell what color a mind is experiencing or capable of experiencing, given a physical description of it. But I'm not sure we should expect this state of affairs to continue forever.

From the sequence on reductionism:

• Hand vs. Fingers
• Angry Atoms

Of course, this only answers to where is the behavior of seeing color -- but then the correspondence between (introspective) behavior and experience is strict, even if the way in which it is achieved may be nontrivial:

• Philosophical zombie
• How an algorithm feels

Reposting my question from upthread:

I'm not quite sure I understand the problem with blueness as you see it.

Suppose nouroscience was advanced enough that it could manipulate your perception of colors in any arbitrary way just by manipulating your neurons. For example they could make you perceive blue as you previously perceived red and the other way round, induce synaesthesia and make you perceive the smell of roses, the taste of salt, the note C or other things as blue. They could change your perception of color completely, leaving your new perception of colors only as similar to your old one as that one was to your perception of smells, flavor or sounds. If all of this was true, would that be enough for you to accept that blueness is sufficiently explicable by the behaviour of neurons alone? Or would you argue that while neurons are enough to induce the sensation of blueness this sensation itself is still something beyond the mere behaviour of neurons?

What would be your reply to

But if reality is nothing but quantum monads in space, and empty space is not red, and the quantum monads are not red, then what is?

Simple "Our experience is what world looks like if you happen to be a bunch of neurons firing inside an apes head" is surprisingly strong reply to the questions you raised. If we take neurons that are put together like they are in brain, and give it sensory input that resembles blue ball, we can ask that brain what it thinks it's seeing. It'll answer "blue ball", and there's nothing weird happening here. Here, answering, thinking or even seeing the blue ball is simply a brain state, purely physical phenomenon.

The mystery, as far as I can tell, happens when we notice that we could theoretically try to see the world as that brain would it see, and suddenly we are actually experiencing that blue ball and all the qualias that come with it. Now the magic is in a much smaller space: There is no magic happening when brain claims it sees blue things, and there's nothing mysterious when we take brains point of view and try to understand how we'd see the world if we were just a brain. So the mystery of consciousness seems to hide in "in a world with no observers, can we sensibly talk about what would the world be like if seen from non-sentient things perspective". If we can, the qualia seem to be in every aspect identical to that perspective.

So what's the ontology of perspective? I have no idea, but perspective seems to go hand in hand with something physical even existing, so we could be strictly materialistic while still acknowledging the existence of qualia.

Color is in the wavelength of the photon. Blue is a label we use to identify a particular frequency range within the electromagnetic spectrum.

(I answer this question, because the discussion of color in the prior post was hopeless from a communication standpoint.)

Consider a simple device, consisting of a chamber containing a measured amount of mercury and a very narrow tube rising from this chamber. As the temperature of the mercury changes, the volume changes as a simple function (roughly linear, but more importantly monotonically). (As the mercury is highly thermally conductive, this temperature is roughly uniform.) This change in volume causes a small amount of the mercury to expand into the narrow tube - the precise amount linearly proportional to the change in volume. It is mathematically clear, therefore, that the height of mercury in the tube is a monotonic function of the temperature of the mercury. The net result of creating this device is a stable, predictable, reliable correlation in the universe between two things - and the tube, therefore, can be marked at intervals (the first thing) corresponding to particular temperatures (the second thing).

We call this a thermometer, of course. And when the mercury is next to the "76" label on the thermometer, we say that this means that the temperature is 76 degrees.

Does this make sense? It would be useful to know whether this sounds like a "wretched subterfuge", as Kant called compatibilist theories of free will.

I think this is a big distraction. As you pointed out in a comment, this is the purpose of the "Where is the chess in Deep Blue?" question, and it has nothing to do with the question you're posing about qualia. That way lies madness and John Searle.

What do you mean by "confabulating"? Do you just mean that people here aren't really confused about this topic?

I accept heterophenomenology only in the sense that people can indeed be mistaken in describing their experiences. On those occasions, you only need to account for the description. But I would say "folk phenomenology" is correct about the basics.

Thank you for the concern, but things have been fairly mellow this time around anyway.

When I was a teenager, I thought about the mind as people here do, at least some of the time. I was happy to think of consciousness as something like a video camera aimed at its own output. But I know that by the time I was 20, I was thinking differently, and I do not expect to ever turn back. It's clear to me that computer science and mathematical physics only address a subset of the world's ontology, and that the reductionisms we have consist at best of partial descriptions, and at worst of misidentifications. Also, in the study of phenomenology, especially Husserl's transcendental phenomenology, I've had a glimpse of how to think rigorously about the rest of ontology.

This is my larger agenda. The problem of the Singularity is being approached within the existing scientific ontology, which is incomplete, and the solutions being developed, like CEV and TDT, are also stated in terms of that ontology. To really know what you're doing, when attempting to initiate a Friendly Singularity, you'd need to understand those solutions, or their analogues, in terms of the true ontology. But to do that requires knowledge of the true ontology.

So, while trying to figure out a better ontology, I have an interest in understanding the thought processes of people who are satisfied with the existing one, because such people dominate the Singularity enterprise. Ideally I'd be able to provoke some sense of philosophical crisis and inadequacy, but obviously that isn't happening. However, I think there has been minor progress. I intend to let the current discussion wind down - to reply where there's more to be said, but not to get into "Yes it is, no it isn't" exchanges - and to get on with the larger enterprise, once it's over. These discussions have all already occurred, at a higher level of sophistication on all sides, in the philosophical literature, and I should relocate the ontological component of my project in that direction.

Not a karma junkie maybe?

The thing is, Mitchell Porter is clearly a very intelligent and thoughtful person, who seems to be sinking huge amounts of his cognitive resources into this pointless, meaningless, doomed project. If we could persuade him of the futility and folly of it, it would probably be worth it.

Last time was "How to think like a quantum monadologist". Having read both, I consider this one superior, thanks to it containing less substance to hold its confusions.

Edit: See SilasBarta's links.

That is a 6,777 word dialogue that covers many things. Can you summarize the part that is an account of aboutness specifically?

Skimming it, you seem to me to be saying that a physical system A is about a physical system B if each state that B is in (up to some equivalence relation) causes A to be in a distinct state (up to some equivalence relation). Hence, the pebbles in the bucket are "about" the sheep in the field because the number of sheep in the field causes the number of pebbles in the bucket to take on a certain value.

I write that summary knowing that it probably misses something crucial in your account. As I say, I only skimmed the essay, trying to skip jokes and blatant caricatures (e.g., when your foil says, "Now, I’d like to move on to the issue of how logic kills cute baby seals -"). My summary is just to give you a launching point from which to correct potential misunderstandings, should you care to.

Agree with Tyrrell_McAllister. You need to be a lot more specific when you make a claim like this.

I see that Dr. Searle stopped by and loaned you some Special Causal Powers™ for your bucket(s) in that story.

I shall have to make a note of this post to use in my Searle work.

The story only addresses how representation works in a simple mechanism exterior to a mind (i.e., the pebble method works because the number of pebbles is made to track the number of sheep). The position one usually takes in these matters is that the semantics of artefacts (like the meaning of a sound) are contingent and dependent upon convention, but that the semantics of minds (like the subject matter of a thought) are intrinsic to their nature.

It is easy to see that the semantics of the pebbles has some element of contingency - they might have been counting elephants rather than sheep. It is also easy to see that the semantics of the pebbles derives from the shepherd's purposes and actions. So there is no challenge here to the usual position, stated above.

But what you don't address is the semantics of minds. Do you agree with the distinction between intrinsic and mind-dependent representation? If so, how does intrinsic representation come about? What is it about the physical aspect of a thought that connects it to its meaning?

Two carriage returns between paragraphs, please - it's hard to read in this format.

I believe you are confused about what Dennett asserts. Quining Qualia would probably be the most obviously relevant essay easily located online, if you want to read him in his own words.

If you don't, the key point is that Dennett maintains that qualia, as commonly described, are necessarily:

1. ineffable
2. intrinsic
3. private
4. directly or immediately apprehensible in consciousness

...and that nothing actually exists with these properties. You see blue things, but there is no pure experience of blue behind your seeing blue things.

Edit: Allow me to emphasize that I do not consider the confusion to reflect poorly upon yourself - yours was a reasonable reading of Mitchell_Porter's characterization of Dennett's remarks. A better wording for the opening of my reply would be: "I think the quote doesn't reflect what Dennett believes."

Well we wouldn't want to "just define" a word that's supposed to refer to something in the world, without figuring out what that thing is yet.

Who are you responding to? I am inclined to believe it is physicalists such as myself, but in that case your remark that about having "reached a dead end and you're desperately banging your heads against the wall" is a non sequitur. I'm not banging my head against the wall due to a dissatisfaction with my worldview, I'm banging my head against the wall due to a failure to find agreement with Mitchell_Porter.