I'm glad it was helpful. One way of "problematizing" the concept of language would be to step back and ask, "What am I/we trying to do by offering the Wikipedia page definition of language?" I think the answer would involve Haslanger's first approach, the conceptual one. The person who refers to the Wiki page is saying, in effect, "We do have a common understanding or definition of what language is, and this understanding is captured by the Wiki page. Our task, then, is to compare possible instances of language to the definition given, and decide whether they fit."

In addition, a possible clarification here would involve asking whether we cite the Wiki page because it captures the meaning of the concept "language," a meaning which we already know and can see reflected on the page; or whether we cite the page because we believe that Wikipedia gives or states correct definitions of concepts, by some sort of fiat or authority. I'm guessing we're not that trusting of Wikipedia, so probably the first idea is what we mean: We already (believe we) have a proper understanding of the concept of "language," and we note with pleasure that the Wiki page captures it well, and so we refer others to it as a basis for discussion. And of course a middle ground is possible: We may not trust Wikipedia implicitly, but we may be swayed by a given page's excellent sourcing and references, so that, if there is a discrepancy between what we think language is, and what the page says, we may give ground to the implied expertise of the page, and modify our concept accordingly.

Do you think this is pretty good picture of your intent here, when you refer us to Wikipedia?

Indeed! Which points up that these approaches all have their merits, and none excludes the others.

I'll try. Haslanger argues that there are four main approaches used to answer "What is X?" questions: conceptual, descriptive, ameliorative, and genealogical.

A conceptual approach would ask "What is our concept of X?" and looks to a priori methods such as introspection for an answer. This approach assumes a sort of "common knowledge" about a concept, at least as it's understood in some dialogical arena. Taking into account differing intuitions about cases and principles, the conceptual approach hopes eventually to reach a reflective equilibrium, with basic agreement on what the concept means.

A descriptive approach is concerned with what kinds (if any) our vocabulary about X tracks. The task is to hold the descriptions as givens, and develop potentially more accurate concepts through careful consideration of the phenomena in question, usually relying on empirical or quasi-empirical methods. In other words, we can change the concept based upon new information.

An ameliorative approach begins by asking: What is the point of having the concept in question—for example, why do we have a concept of "language"? What are we using it to talk about? What concept (if any) would do this conversational work best? Is "language" that concept? This approach often ends by proposing a better or more useful understanding of a concept, in terms of getting the job done. Or it may recommend abandoning the concept entirely and replacing it with another that gets better results.

A genealogical approach explores the history of a concept, not in order to determine its true meaning by reference to origins ("truth by etymology"), and not for "sheer historicist fascination," but in order to understand how the concept is embedded in evolving social practices. What role does the concept play in our web of beliefs?

So, for this thread, consider one of the opening questions:

What is the difference between language and communication, if any? — KrisGl

What kind of question is this? What sort of "difference" is being examined?

We could start by asking, "Which of the above approaches are you using to ask this question? Are you interested in how our language-using community of philosophers defines these two concepts (conceptual approach)? Are you asking what sorts of things fall under the heading of 'language' and 'communication,' with an eye toward refining the concepts accordingly (descriptive approach)? Are you asking why we need to have these two concepts in the first place, and perhaps proposing a useful discrimination between them in order to achieve our goals (ameliorative approach)? Or are you interested in knowing how the two terms have evolved within a matrix of social practices here in the U.S. (or the West, or whatever social group seems relevant) (genealogical approach)?"

This hardly does justice to Haslanger, but at least it gives you the flavor. She is pointing out how often we charge into some Big Question about, e.g., language, without first clarifying the kind of inquiry we're making. Is it about words? concepts? practices? best practices? You mentioned metaphorical and literal uses of "language," and that's just the sort of issue that could be approached by asking, "OK, what would 'a literal use of language' be? What concept of language are we going to be talking about here? Is it written in conceptual stone, so to speak? Is there somewhere we could look it up? Maybe we could come up with a better, more descriptive, more useful definition..." etc etc.

Or avail yourselves of this excellent paper by Sally Haslanger that discusses different approaches to answering "What is X?" questions. The "what is a language" question in this thread is a classic example of what she's discussing. (If you're not interested in her opening issues, concerning the language of race and gender, you can skip to p. 12, where she lays out her overall strategy.)

For awhile now I've been searching for a diagnosis of what the exact philosophical issue is that collectively Mainstream, Non-mainstream, and layman physicists have had regarding modern scientific practice. — substantivalism

This is an interesting topic, but I had trouble following you in the ensuing paragraphs. Is it possible for you to offer a fairly short answer to the question you're posing, above? What is the best diagnosis, according to how you understand the issues? Or are there several candidate answers you could draw our attention to?

Thanks, I agree it would be better if we had a good neutral term that wasn't steeped in philosophical history, but I don't know of one either. As long as we both understand each other . . .

As for Quine: "Two Dogmas" only questions analytic statements that are supposed to be true by virtue of meaning-synonymy. If you go back and look at the start of the paper, you'll see that he exempts logical truths.

Now that I think of it, @Srap Tasmaner and I discussed this earlier in the thread:

Quine himself had very mixed feelings about whether the laws of logic were subject to revision. I think his final answer was yes, but it's a last resort, and they are very insulated, resistant to revision.
— Srap Tasmaner

Just as an aside, I think Quine believed the laws of logic were true because we could supply clear definitions for all the operators and connectives. This is in Word and Object. In a subsequent work which I haven’t read, The Philosophy of Logic, he extends this to non-classical logics, according to [Susan] Haack. She says that he accepts “a meaning-variance argument to the effect that the theorems of deviant and classical logics are, alike, true in virtue of the meaning of the (deviant or classical) connectives; which, in turn, seems to lead him to compromise his earlier insistence that fallibilism extends even to logic.” — J

I think the key difference here is "true in virtue of meaning" (of the connectives) as opposed to some kind of truth that is dependent upon empirical facts. If this is right, then math and logical truths wouldn't depend on anything of the latter kind. But anyone who knows where Quine ended up on this should weigh in.

I question whether mathematical axioms count as 'phenomena', which is 'what appears' — Wayfarer

I tried to pick the most neutral word possible. Is there a better term for the denizens (another neutral word!) of the "formal realm"? Happy to use it instead.

Quine’s critique where he argued that even mathematical axioms aren’t purely necessary but depend on the broader network of empirical and theoretical commitments. — Wayfarer

Is there a particular reference you have in mind? Quine's position wavered over the years.

The invisible and visible can't resemble each other unless we make both visible. — jkop

Why not? I must be missing something still. I thought such a resemblance was the point of your saying that "there can be resemblance between two states of affairs such as seeing things and thinking about things." One is visible, the other not. Oh well. Not a terribly important point, either way.

Ah, but can you? — Wayfarer

Good response. Maybe we need three categories: 1. genuinely contingent physical phenomena; 2. phenomena which we can imagine were otherwise but in fact could not be; 3. phenomena like mathematically necessary statements, which we can't even imagine to be otherwise.

I see three distinct grades of necessity in those three categories. 2 and 3 may both produce outcomes that are, in practice, non-contingent, but our ability to imagine 2 otherwise, but not 3, has to make a difference, modally. Rough guess -- 2 is about necessity of Being, 3 concerns necessity of Thought. The capitalizations are meant to indicate that these are placeholder terms, having something to do with the synthetic/analytic division.

There just isn't any reason to make the visible/invisible comparison central to resemblance.
— J

I didn't. — jkop

Not to run it into the ground, but here's what you said:

A resemblance-relation requires at least two objects which can resemble each other. Granted that all objects resemble each other in the abstract sense of being objects, but how can anything invisible resemble something visible?

My point is that they can't, unless you somehow make both visible. — jkop

Surely that makes visibility "central to resemblance" -- indeed, it sounds like the criterion for it ("you can't, unless . . .").

there can be resemblance between two states of affairs such as seeing things and thinking about things. — jkop

Good, this all makes sense. So why can't we claim that the "non-seeing" resemblance relation is just as central as the seeing one? You'd asked earlier, "How can anything invisible resemble something visible?" but I think you've answered your own question correctly. There just isn't any reason to make the visible/invisible comparison central to resemblance.

J: whether “the facts under question arise from a degree of mathematical necessity considered stronger than that of contingent causal laws.”

Isn't "contingent causal law" a contradiction in terms? — RussellA

The term does invite confusion as it stands. If you read the paper, you see that what Jha et al. mean by "contingent causal laws" is no different from your "nomic laws." They're called contingent to distinguish them from mathematical necessity, which the authors believe is modally stronger. They're also contingent in the sense that we can easily imagine a physical world with different constants, different explanatory equations, etc. In this world, to be sure, they are nomic.

I'm trying to get at your reasoning here. — Harry Hindu

OK. My reasoning is based on what we would reason about the phenomenon of "life." As far as I know, the efforts at creating artificial life are all biologically based. I'm not aware that any scientists are working on the idea that a silicon-based digital entity might "come alive," begin reproducing, and/or provide evidence that it is having inner experiences such as animals have -- pain, for instance. (But by all means point me to any interesting new research along these lines.)

So, similarly, I'm guessing that consciousness will turn out to be a property of living organisms exclusively. Why? Because whatever it is that makes an entity alive is going to be turn out to be what makes it conscious. Or perhaps speaking of "subjectivity" is better here, as I don't know that a plant could be conscious but I find it plausible that it has experiences.

How likely is this to be true? I can only say "fairly likely" based on what we've seen so far: absolutely no evidence of either life or consciousness in digital entities. This gets muddled because proponents of mechanistic consciousness will define "consciousness" in such a way that a digital entity might have it (I think that's what you're doing, to a degree), so perhaps it's ultimately a philosophical rather than a scientific issue.

For you, who else? — Harry Hindu

But how can any such entity as "me" emerge from a working memory and sensory info processing? I think you're assuming that the digital toolkit will produce a "me" or a subject, but that's the very thing under discussion.

If my description does not resemble what it is like for you, then please explain what it is like for you. — Harry Hindu

Well, I am a subject, so in addition to all the ruckus going on, I experience my self. Transcendental ego, if you like. Moreover, as a subject I do a lot more than connect with the "outside" world. My imaginative consciousness is extremely vivid, and doesn't depend on stimuli from experience, unless we beg the question and say that it's the neuronal activity itself that is the stimulus. But I don't think brains cause consciousness, I think consciousness supervenes upon brains.

However, the general thrust of what you're saying is important and true -- WE DON'T KNOW. It is one of the great remaining scientific puzzles.

You're quite right; as I said, we don't yet know any of the important facts that would allow us to decide this. I haven't assumed anything. I've said that I think it's unlikely that non-biological entities will turn out to be conscious.

If we say that consciousness is a type of working memory that contains sensory information . . . — Harry Hindu

Well, yes, then various things follow, but I don't think that's a good thing to say. My own consciousness doesn't at all resemble this description phenomenologically, and once again we're a long way off from being able to say that, despite this, it "really is" working memory plus sensory information. Just for starters, for whom is the information informative?

how can anything invisible resemble something visible? — jkop

It's hard to know what sort of answer is wanted here. I could reply, "Easily. When I read a biography, my mental imaginings of the subject of the biography resemble the subject quite a bit, if the book is well-written." This is ordinary-language talk, and no ordinary speaker would have any difficulty understanding me. But evidently you want to stipulate a meaning for "resemblance" that makes physical visibility more important as a criterion. I guess you can do that, but I think we need 1) an explanation for how the ordinary-language use became so common, and 2) a good argument for why this notion of "resemblance" is useful or clarificatory, in this context. What are you trying to ameliorate, with this usage?

Therefore, we can use the Correspondence Theory and say that the proposition "there are infinitely many prime numbers" is true because there are infinitely many prime numbers. — RussellA

Good, I think we're on the same page. A correspondence theory ought to work independently of the ontological status of various "worlds"; that was why I questioned limiting it to "facts about the world," which from your example I took to refer to the more-or-less-physical world that would exist without us. But now I see that your view is more inclusive, so that's fine.

But that's the thing. What makes a mass of neurons conscious, but a mass of silicon circuits not conscious? — Harry Hindu

We don't yet know. My hunch is that it's going to be a version of the same thing that makes a biological creature alive, and a computer not. And yes, this could all be off base -- the sort of thing people will marvel it a few centuries hence -- "How could those people have gotten it so wrong?" But for the moment, I haven't heard of anything that suggests a computer could have inner states. Do you know of anything along these lines? (Grant me, for the moment, the idea that an inner state would be a sign of consciousness.)

If a correspondence theory of truth demands that we do so, I'd argue that it represents a reductio ad absurdum and should be rejected on that ground.
— J

Very harsh. The word "true" has different meanings in different contexts — RussellA

So, to review the set-up here: The question is whether a standard correspondence theory has to invoke a match between statements in a language and facts about the world. If so, this would seem to rule out using such a theory to describe strictly logical or mathematical facts as true. Yes, you could say that, to demonstrate such facts, we don't need a correspondence theory and therefore we can call them true using a different meaning of the word. But isn't that a stretch? The appeal of a correspondence theory is that it seems to give a common-sense reply to the question of what it means for a statement to be true: We compare it to what is the case, and if it fits, bingo. Obviously it can't be that simple, but the concept is still powerful.

So, Euclid's proof about prime numbers claims to state a truth. When we examine it, we see that while it isn't exactly a "truth about the world," or something that is made true by facts found in the world, it nonetheless appears to express a match of language with something. What is the something? For me, none of the usual-suspect answers involves giving up using "true" to mean "agrees with what is the case." So we shouldn't limit a robust correspondence theory to "facts about the world" -- there are plenty of other facts that we want to call true in the same way. I can't defend that here, but I just wanted to give you a sense of where my objection is coming from. And yes, maybe calling this version of the theory a reductio is a bit harsh, but at the very least it requires a strong argument against its implausibility.

Any word yet on casting for L&L? I heard Tom Cruise was in the running to play Science. Or was it Metaphysics . . .

You might ask, 'Why would we need to be conscious of an imagining?" Why can't a p-zombie do the same thing but without the actual experience of imagining a purple cow? The answer is that I don't think the p-zombie is a valid argument. — Harry Hindu

I have a lot of questions about p-zombies too, but we don't need them in this instance. Any number of computer-generated entities can do all the things you mention: respond to their environment, learn, make predictions, use feedback loops, offload routines to different parts of memory. So I disagree that "Consciousness is necessary for learning and making predictions." This is why the purple cow is such an annoying example -- it doesn't do anything. It simply sits there, so to speak, being a mental image, again so to speak. If a computer-generated entity could do this, I would have to allow that it might be conscious, but I don't believe it can. Except by rather strained analogy, there's no equivalent of a digital state that also has a subjective appearance to the software that we cannot experience.

Having said this, some computer-savvy poster is going to show me I'm wrong! OK, I'm ready. . .

This is Jha et al’s argument, more or less. Math only appears to be causal when we state the problem in terms that remove, or demote to “background conditions,” the physical constraints that actually provide the explanation.

This is good. I would amend it slightly: Jha et al are asking the very question about whether logical principles can be more than contingently causal. They’re not at all “unwilling “ to entertain the idea; it’s the topic of their paper. They do end up arguing against it, true.

Interestingly, you've made similar arguments to those of @Philosophim about "effective" truths, and my response to him, just above, is similar to the one I'd make to you. It may well be that scientists don't much care whether equations are true, as long as they work. But philosophers -- and, I'm guessing, a lot of mathematicians -- care very much. We can't take "facts in the world" for granted and go about our business. A theorem (as opposed to an equation that's given a real-world interpretation) isn't described as effective, it's described as true, or at least provable in L. Do you want to abandon that way of talking? If a correspondence theory of truth demands that we do so, I'd argue that it represents a reductio ad absurdum and should be rejected on that ground.

Within the modern correspondence theory, "snow is white" is also within the object language whilst snow is white is a fact in the world. — RussellA

Similarly, I agree that this is a familiar version of a correspondence theory, but it leaves out the option of claiming truth for any facts that are not about the world (unless there's a "world" of math and logic). Is that OK? What would be the point of limiting ourselves in this way?

What a cromulent response! :smile:

This just pushes the question back a level -- why is it effective?

Now of course the picture you're painting is a perfectly good one if you're a pragmatist, or believe for whatever reason that metaphysical questions about the correspondence of thought and reality are either incoherent or unanswerable. But I keep pressing you on your use of "accurate representation" -- "accurate" simply doesn't mean the same thing as "effective" or "successful." Wouldn't it make more sense for you (if I've understood your thinking here) to abandon any talk of accuracy or truth?

Well, perhaps, but how can "accuracy" be a factor at all? What would make something an "accurate representation," to use your phrase, and of what is it a representation? None of the three factors talk about how such an idea could arise.

To put it in simple terms (borrowed from Sider), are we really not in a position to say that the Bleen people have gotten something wrong?

My understanding of truth is that it is defined by the schema "snow is white" is true IFF snow is white, where "truth" is the correspondence between propositions in language and equations in mathematics and what is the case in the world. — RussellA

Is this meant to be Tarski's view? Surely he didn't talk about what was the case in the world -- only about the correct relations between language and metalanguage. If one language has to be "about the world," then we wouldn't have any logical or mathematical truths at all, or at least that seems to be the necessary consequence. I don't think Tarski intended this. Unless I'm mistaken, he included these kinds of truths in his schema.

This is a great description of what mental imaging is like, and accords completely with my own experience. But then what do you mean when you say:

A "mental image" couldn't even resemble visible objects such as cats or images — jkop

What it's like to see the cat is a feeling, not an image. — jkop

Doesn't your description contradict these statements?

I appreciate your taking the time to lay all this out for me. Could I ask you to take this to a simpler level, and describe to me what you think happens when I imagine a purple cow? I'm still concerned about the hard problem, understood as the emergence of subjectivity (or the illusion of subjectivity, if you prefer) from chemical/neuronal activity,

I understand. Do you think there are mathematical truths that are independent of what is the case in the world? Plain old theorems, in other words?

OK, but you can see that even this weakened version represents an entirely different order of explanation than:

1. Real life effectiveness

2. Fulfills emotional desires

3. Fulfills a power structure

By referring to "accurate representation," you've introduced an epistemologically normative factor that is nowhere implied in the first three factors.

I find all this somewhat plausible in the case of images that arise from perception of the world, and are meant to "stand for" or "picture" or "represent" something out there. Quite possibly the "out there / in here" duality is either mistaken or badly conceived. But . . . I don't see how it applies to my purple cow, or any other of the myriad ways consciousness operates without any perceptual stimulus. We agree that my imagining the cow is no illusion. How is this still a question of dualism vs. monism? I'm not claiming that the cow represents anything in the (dualistically conceived) world; in fact, the choice of "purple cow" is meant to preclude any such representation.

You'd written this:

Are mathematical truths necessary truths
Following the schema "snow is white" is true IFF snow is white as a definition of "truth", then "d=0.5∗g∗t2" is true IFF d=0.5∗g∗ — RussellA

So I assumed you regarded d=0.5∗g∗t2 as a mathematical truth.

What do you mean that the equation d=0.5∗g∗t2 has no meaning? — RussellA

Without some interpretation, some assigning of the symbols, it says nothing. I can vouch for this personally, as I have no idea what d, g, and t refer to in this equation! If you simply placed it in front of me, uninterpreted, and asked me what it meant, I could only shrug.

But if none of that is so, and what I was calling "subjectivity" is in fact a dualistic illusion, we still need to know how this comes about, and why.
— J
But that is what I've been saying - that seeing this as a dualist illusion IS the problem. Abandon dualism and introduce the idea of monism and see if that helps you solve the problem. — Harry Hindu

We agree that subjectivity could be a dualist illusion. (I don't think it is, but I'm happy to assume it for purposes of argument.) But if it is, we still need to know why. You say, rather cavalierly, "Abandon dualism." OK, I imagine a purple cow and I follow this up by saying to myself, "This experience of me-and-purple-cow-image is illusory. There is no separation." But this doesn't make the purple cow go away, or change into something else. I'm sure you don't believe this would happen either, but what do you believe? What changes, for you, in this sort of experience when you introduce the idea of monism? Is it that experience, as presented, becomes a sort of brute fact, about which it's no longer possible to ask questions? This isn't meant to be snarky, I'm genuinely interested.

A "mental image" couldn't even resemble visible objects such as cats or images — jkop

For me, a mental image strongly resembles a visible object. So I can only conclude that you're already analyzing "mental image" reductively to refer to whatever physical substrates it may supervene upon. I think that begs the question.

What it's like to see the cat is a feeling, not an image. — jkop

Again, I have to say, Not for me. We all know that "what it's like," despite having become the go-to term for subjective experience, is quite imprecise. Maybe that's a good thing. In my case, the "what it's like" is a combination of an apparent image, often a series of memories associated with the image, probably some future projections about the image, and, sometimes, a feeling about what I'm imaging.

It sounds like where we differ is that you want to eliminate the idea of a mental image altogether. I think there are plausible and persuasive reasons for doing this in the case of perceptions. But not for imagined or remembered images. If these experiences are not, in some ordinary-language way, mental images, then what are they? And how could they be explained away as being identical with their physical substrates?

Are you sure we should call something like d=0.5∗g∗t2 a mathematical truth? I thought it was only true on some interpretation; as it stands, it has no meaning.

Let me try to work up an example that is less controversially stipulative. — J

How about this?

For "object" in the "23 objects" question, let's say "chickens." We wish to divide 23 living chickens evenly among 3 people; we discover this can't be done. Here there's no question of how to define the object, or whether fractions can ride to the rescue. So: Is this division impossible for the same reason -- a distinctively mathematical one -- that the number 23 can't be divided evenly by 3? Or, if you don't accept "distinctively mathematical," how would you characterize it?

OK. So no one of your factors would be something like "This set of concepts more accurately reflects the ontological structure of the world"? You'd rely on pragmatic and/or personal-preference explanations for the chosen set of concepts?

Cool comparison, I hadn’t thought of it!

I don’t think I agree with your interpretation, though. You recall that Quine’s target was meaning-synonymy as a supposed criterion for analyticity. He readily acknowledges, at the start of the paper, that logical truths are excluded from his criticism. So we have to ask, is there a “parallel exclusion” in the case of explanations that include part math, part facts-about-the-world?

Taking the math part to be parallel with “analytic,” we want to know whether maths are logical truths (and thus both easily identifiable and unexceptionable, according to Quine), or whether they are more like meaning-synonymy statements. Frege may be helpful here; he also divided analytic statements into two groups. The first is Quine’s “logical truths”; the second is supposed to be reducible to logical truths on the basis of purely logical definitions. As Susan Haack points out (in her Philosophy of Logics), this would mean that “the truths of arithmetic are, in this sense, analytic.” (And Kant, of course, would disagree.)

Do Jha et al. take a roughly Fregean stance here, concerning the relation of math to analyticity? They don’t address this directly, to be sure, but I think they do. The reason lies in their reasons for rejecting distinctively mathematical explanations (DMEs) in the first place. Math, according to them, can’t play an explanatory role in scientific explanations because it can’t say anything about “the world,” due to its a priori nature. Now I know Kant though math could be both a priori and synthetic, but that has never struck me as plausible, and I think we should go with Frege. (And anyway, as @schopenhauer1 pointed out, the synthetic nature of math for Kant is transcendental. It operates as we structure experience, it’s not something we learn “in the world.”)

So if we attribute the Fregean stance to Jha et al., then they don’t say that “you cannot tease out any supposedly pure math part, roughly”. It’s precisely because you can do this that DMEs won’t work.

Still, it’s not a simple question, and I’m not sure I’m right.

Quine himself had very mixed feelings about whether the laws of logic were subject to revision. I think his final answer was yes, but it's a last resort, and they are very insulated, resistant to revision. — Srap Tasmaner

Just as an aside, I think Quine believed the laws of logic were true because we could supply clear definitions for all the operators and connectives. This is in Word and Object. In a subsequent work which I haven’t read, The Philosophy of Logic, he extends this to non-classical logics, according to Haack. She says that he accepts “a meaning-variance argument to the effect that the theorems of deviant and classical logics are, alike, true in virtue of the meaning of the (deviant or classical) connectives; which, in turn, seems to lead him to compromise his earlier insistence that fallibilism extends even to logic.” So it sounds like your "very insulated, resistant to revision" is spot on.

By clarifying their ambiguity we can get rid of some of the problems.

For example, in talk of the experience of seeing a cat, the word 'experience' or 'seeing' can refer to what is constitutive for having the experience: the feeling. But they can also refer to what the experience is about: the cat. — jkop

Good, this is helpful. I'm not using "experience" to refer to what the experience is about (the cat). But nor am I quite using it to refer to a "feeling." I suppose people can differ on this, but when I see a cat, I don't find myself feeling much of anything about it. What I do find is that I have, or seem to have, a mental picture. This is, for me, what is "constitutive of having the experience," as you say. But I don't think it matters too much whether the "inner" part is more like a feeling or more like a picture. The important difference, which you have disambiguated, is between "experience" understood as the object (putatively "out in the world") that is being sensed or thought of, and the subjective event of doing so.

So, what is left to explain is this: How does my brain create the feeling?, and I believe we know at least something about how feelings are evoked by hormone levels, neurons releasing dopamine etc. — jkop

But here, your reliance on "feeling" as the correct subjective description does make a difference. It allows you to talk about hormone levels, dopamine, etc., as possible causes of feelings. I'm sure they are. But the kind of "feeling" involved in having a mental image of a cat is surely not explainable by hormone levels. I know you're not saying that it is, only that we're not as ignorant about the whole process as I've been arguing. I'm not persuaded, though. Can you sketch even the beginning of an explanation of a mental image that involves feeling-type causes such as hormones or other chemical items? I think this would be even harder to do in the case of an imagined image -- one that I simply "think of" as opposed to being stimulated by a perceptual event.

The impossible request that we ought to explain how hormone levels etc create the illusion of a Cartesian theatre seems to be based on a fallacy of ambiguity. — jkop

Can you explain? I thought you disambiguated it nicely. Is this a different ambiguity?

I realize I've been using the term "privileged structure" without much explanation, as if everyone is familiar with Theodore Sider. Let me expand a little. Sider uses the "grue and bleen world" example (which you can read about here, p. 16) to refer to a situation that he believes needs explaining: If we encountered a people who used grue and bleen as their concepts, we'd be unable to fault them on any logical grounds. Nor would anything in the world contradict their choice of these concepts, as concepts -- there really are grue and bleen things, and we know how to say true and false things about them. They would of course prove completely unworkable in practice. But why? What makes our green-and-blue conceptual world better? Is it simply a pragmatic question? But that only pushes the question back a step, for now we have to ask, Why does it work better? Is that just lucky for us, or is there something about the world, and its structure, that green-and-blue reflects with more than mere accuracy? If so, that would be a privileged structure in Sider's sense, and the grue-and-bleen world would not.

So, on that understanding, how would you explain privileged structure? I can see how you can demonstrate the pragmatic success, but what's the next, explanatory step?