I’m sorry but I just don’t understand what you’re asking.

These are all physical events. — schopenhauer1

And it might be a physical fact that a sufficiently advanced brain will cause first person experiences.

How does this not avoid the homunculus fallacy though? The ghost is already in the machine. That is the very thing to be explained though. It's too "just so" or "brute fact" perhaps? — schopenhauer1

I don't understand the issue. If I say that it's an unavoidable, deterministic consequence that heating an ice cube above 0 degree celsius will cause it to melt, am I committing an homunculus fallacy?

One problem with this privacy talk is the implied possibility of a p-zombie. — green flag

Certainly a logical possibility. Maybe not a physical possibility. It could be that first-person experiences are an unavoidable, deterministic consequence of a sufficiently advanced responsive organism.

If AI gets good at reading your mind, will that change your mind ? — green flag

Depends on how it works. If we ask people what they feel when this area of the brain is activated, and they say pain, and then we feed this information into an AI, then that the AI is able to check to see if that area of the brain is activated and tell me that I feel pain isn't "mind reading" at all.

If it could know that I'm in pain despite not knowing anything about how brain activity correlates to self-reported feelings then that would show evidence of mind reading, and would suggest that first-person experiences are reducible to physical phenomena, and so not essentially private.

then ordinary means of referring that appeal to a causal linkage between another speaker and my experiences are ruled out. — sime

I dispute that requirement. I can talk about the future.

If experience is truly private, than it is presumably impossible to even refer to someone else's experiences in the literal sense of "someone else". — sime

How so? I don’t need to experience something to talk about it.

Consciousness, whatever it is, doesn't extend beyond the brain, and so it's physically impossible for an apple and its properties to be "present" in my conscious experience. It might be causally responsible for conscious experience, but that's all it can physically be.

This is the “illusion” of experience (and in particular sight), and is I believe the driving force behind direct realism. It seems as if external world objects are “present” in my conscious experience, but our scientific understanding of the world and consciousness (as much as we do understand it) shows that this isn’t the case.

We might nonetheless want to say that the experience is of external world objects, but then what do we even mean by this? What is the word “of” doing here? What does it mean to say that the painting is of Lisa del Giocondo, or that I’m talking about my parents? It’s certainly an interesting question to consider, but I wonder if it actually has anything to do with the epistemological problem of perception. It seems to be an unrelated issue of semantics that isn’t prima facie incompatible with indirect realist theories. The painting is of Lisa del Giocondo, and yet the painting is made of paint and canvas, which are not features of Lisa del Giocondo herself. And so it could be that the experience is of an apple, and yet the experience is made of something like brain activity or sense data or rational inferences, none of which are features of the apple itself.

Notwithstanding that conceptual confusion, I'm not disagreeing that colour is a construction of the brain's processing systems, I'm denying that it is thereby not a property of external nodes. — Isaac

But the stuff that's constructed by the brain's processing isn't stuff that's in or on the apple. And I mean that in a very real, physical sense. My brain isn't the apple. They are located at separate points in space, composed of separate pieces of matter (and energy). So at the very least you should accept that the word "colour" when referring to the stuff constructed by the brain's processing means something different to the word "colour" when referring to some property of the apple.

Perhaps you might argue that even if the stuff constructed by the brain is a different token to the stuff in or on the apple, they are of the same type? But then we should be able to measure the apple and measure my brain and find the same type of physical stuff going on. But that's certainly not the case. When we measure the apple we find that it reflects light with a wavelength of 700nm, but when we measure my brain we don't find that it reflects light with a wavelength of 700nm.

And that's why I've said before that there's an element of equivocation in the direct realist's argument. That we might use the same word to refer to both cause and effect isn't that they are the same thing. Colour experience is one thing, and apples reflecting light is a different thing entirely.

You're going to have to explain the connection there. What does not being able to access something have to do with not being able to talk about that thing? I can't access the contents of your safe, but I can talk about the gold bullion locked inside.

The full quote was this:

This is a basic problem first of even knowing whether similar/the same phenomena are experienced the same way because the experience is private and only accessible first-person.

Seems pretty clear that he's only saying that because we can't experience another person's experiences we can't know what it's like to experience as they do. Doesn't seem to say anything about what we can or can't talk about. It may be that his pain is nothing like my pain, but that's not to say that we can't talk about his pain being like, or not like, my pain.

That's the problem with Andrew4Handel's proposal that "the experience is private and only accessible first-person" - it implies that only he can talk about such an experience. — Banno

This is where you equivocate. To say that an experience is private is just to say that no-one else can experience it. It says nothing about who can or can't talk about it. There's no prima facie connection between not being able to experience something and not being able to talk about that thing. I don't need to see something (like the beetle in your box) to talk about it. The blind manage just fine in that regard.

Yep. That's why your pain is not just a thing inside your head that only you can refer to. If it were, no one else could talk about it. — Banno

I didn't say that only I can refer to it.

Pain is a thing inside my head that we can both refer to.

It is, in Wittgenstein's example, the label given to the box. — Isaac

I'd say it's the label given to the contents of the box. That's why we use the word "private" in the phrase "one's own private thought". If it was a label given to the box, which is public, then the phrase would be "one's own public thought".

Or, to use Wittgenstein's example, the phrase "the contents of the box" refers to the contents of the box, not to the box itself.

And I don't see why we can't coin a single word that refers to the same thing as the phrase "the contents of the box". How about "beetle"?

As in, If only you can refer to your pain, then I cannot refer to your pain. — Banno

I'm not saying that only I can refer to my pain. You can refer to my pain as well.

My feeling of pain is private in the sense that only I can feel it. But it's "public" in the sense that we both can talk about it.

And the beetle I see inside my box is private in the sense that only I can see it. But it's "public" in the sense that we both can talk about it.

Of course you can. So it's not private. That's the point.

A private language is one only you understand. — Banno

Again you seem to be equivocating. I'm not saying that there's a language that only I can understand. I'm saying that words can refer to things that only happen inside our heads. The word "pain" for example refers to a thing that happens inside our heads. It doesn't refer to some public expression of pain, like saying "I'm in pain" or taking aspirin.

What I don't seem able to do is give a similar account of what using a word privately to refer to one's own private thought might be. — Isaac

Why not? If a phrase like "one's own private thought" can refer to one's own private thought, then why can't a word? Is there some bizarre condition that a single word can't refer to a private thought but a multiple word phrase can?

But if you can talk about it to others, then it is by definition not private.

And so, since we are talking about it, it's not happening only inside your head. — Banno

You're equivocating.

We might use the word "private" to mean "something that can't be talked about" or we might use the word "private" to mean "something that only happens inside my head" but these are two different definitions.

So let's just not use the word "private" and I'll simply say:

I can talk about something that only happens inside my head.

If one sets up a private thingie, one become unable to talk about it. — Banno

That's what I reject. Just because it only happens inside my head isn't that I can't talk about it. Just because you can't see the contents of my box isn't that I can't talk about what's inside.

What I don't seem able to do is give a similar account of what using a word privately to refer to your own private thought might be. — Isaac

You make the same inconsistent argument that Banno made above. Presumably the phrase "your own private thought" refers to my own private thought.

You can't show me a copy of your pain, or your red qual. — Banno

Even if you can refer to it, and that is not clear, it does not refer to anything someone else can refer to, so it drops out of the conversation. — Banno

These seem like inconsistent claims. You start by referring to my pain, seemingly accepting that it’s inaccessible to you, and then say that you can’t refer to my pain.

Don’t quite get what you mean. When I talk about the beetle in my box my words are referring to the thing inside my box. The thing inside my box is what I understand a beetle to be. That you can’t see inside my box and I can’t see inside your box is irrelevant.

Now imagine I was shown a copy of what is in your box. Would I recognise it as being a beetle? Only if it looks like what’s in my box. Irrespective of how I use the word, it refers to and means something to me.

A private language is a language that someone else cannot understand. Hence, if something is private, the it is not available for discussion.

Yet synesthesia, and pain, and the colour red, and so on, are available for discussion. Hence they are not private.

So there is something deeply problematic in philosophical discussions that propose private "phenomena" that they then proceed to describe in detail. — Banno

By private phenomena I don’t mean phenomena that can’t be talked about. I mean phenomena that “happens” to one person but not to another. When the person with synesthesia sees the number 7 as red and talks about it being red he is referring to a phenomenon that I have no access to. I can’t see that the number 7 is red. The redness of the number 7 isn’t some mind-independent property of some external world object that I can test for. The redness of the number 7 is entirely “inside his head”, and that’s what I mean by private. And yet he can talk about it and I can understand it (to an extent).

Anyway, that's a side issue to your suggesting that synesthesia is problematic for Wittgenstein. Have you droped that view?

No.

So, going back to your question, how does any of this pose a problem for Wittgenstein, or for Davidson? It seems to me to reinforce his point, that what we talk about is public, and if it is private it drops out of our conversation.

And that is pretty much what I would offer as "what I mean" by private and public. — Banno

I still don’t understood what you mean by “private”. It sometimes seems that by it you mean something that can’t be talked about, in which case it’s a truism that we can’t talk about something private. Is that all you mean? Because that makes for the claim that “what we talk about is public” the redundant claim that “what we talk about is what we talk about”.

It isn't evidence at all, of any private unsharable phenomena. — Banno

This is one such example. By “unshareable” do you mean “can’t be talked about”?

It’s not what I mean. I can talk about my experience, but I can’t show you my experience. You can’t share in my experience. That’s what I mean by “private” and “unshareable”. My experience is mine alone, but I can still talk about. So I am talking about something private and unshareable.

Yeah, you can, because they can tell you. Indeed, that's how we know about synaesthesia. — Banno

And the critter tells me that the water is green. So why is that evidence that he means something different by the words “red” and “green” but the person who tells me that the number 7 is red is evidence of synesthesia?

It's not private. — Banno

I don’t quite understand what you mean by “private”. His experiences, the things he talks about, definitely are private; I can’t see them for myself. I just have to take his word for it that things are as he says they are.

How could you tell they see the water as green? Ex hypothesi, there is no distinction here. What difference would there be between the critter saying "There is a good quantity of water" and "the water is green"? — Banno

I can’t, that’s the point, just as I can’t tell that someone sees the number 7 as red. But people really do see the number 7 as red, much in the way that I see blood to be red. So I think the notion that meaning must be related to some public measure of use doesn’t work, and why I’m suggesting that the empirical evidence of synesthesia is evidence against Wittgenstein’s armchair philosophy.

I suppose we can’t know for certain, but we can make reasoned assumptions. We know that the same kind of stimulus causes in ourselves the same kind of experience, e.g. light of a particular wavelength causes us to see a particular colour (the colours you see aren’t random). So we have evidence that the relationship between a stimulus and the subsequent experience is deterministic. It then stands to reason that if your physiology is much like mine then the relationship between that same stimulus and your experience will follow much the same deterministic process, and so that your experience will be much like mine.

I think there’s a distinction between sense and reference. It may be that the sense of a word is public, but I think sometimes its referents are nonetheless private. In the case of the person with synesthesia, when they talk about seeing red when hearing music they are talking about something that I cannot see. They are referring to some aspect of their experience that, perhaps in principle, I am unable to access for myself.

And if we return to the example you gave of the red and green water, perhaps such a person has some special kind of synesthesia and they quite literally see the water to be green when it is of a certain quantity and red otherwise. How does that affect your conclusion that a person who describes water as being red or green depending on its quantity must therefore be using the words differently and so mean something different?

I’m saying that the colours they see and talk about are private to them.

How does Wittgenstein account for something like synesthesia? Some people talk about sounds and numbers having colours. It’s certainly a non-standard way to use colour vocabulary, and yet we have some idea of what they mean. How could we even make sense of something like this if we don’t think of colour terms as referring to something that’s going on “in their head” (and not in ours)? It would be incorrect to say that such people just don’t understand English and are using the words “wrong”.

But make no mistake: Your "job" -- the useful thing you do for other people -- is all you are.

Might be all I am to them, but it's not all I am.

The experiment you've provided shows none of these three claims. — Isaac

It shows, as it says, that "color is in the perceiver, not the physical stimulus" and "color is a perceptual construct that arises from neural processing".

You're not going to convince me that it isn't saying what it's literally saying.

What empirical evidence? — Isaac

I've already given one example:

There is no color in light. Color is in the perceiver, not the physical stimulus. This distinction is critical for understanding neural representations, which must transition from a representation of a physical retinal image to a mental construct for what we see. Here, we dissociated the physical stimulus from the color seen by using an approach that causes changes in color without altering the light stimulus. We found a transition from a neural representation for retinal light stimulation, in early stages of the visual pathway (V1 and V2), to a representation corresponding to the color experienced at higher levels (V4 and VO1). The distinction between these two different neural representations advances our understanding of visual neural coding.

...

Color is a perceptual construct that arises from neural processing in hierarchically organized cortical visual areas. Previous research, however, often failed to distinguish between neural responses driven by stimulus chromaticity versus perceptual color experience. An unsolved question is whether the neural responses at each stage of cortical processing represent a physical stimulus or a color we see. The present study dissociated the perceptual domain of color experience from the physical domain of chromatic stimulation at each stage of cortical processing by using a switch rivalry paradigm that caused the color percept to vary over time without changing the retinal stimulation. Using functional MRI (fMRI) and a model-based encoding approach, we found that neural representations in higher visual areas, such as V4 and VO1, corresponded to the perceived color, whereas responses in early visual areas V1 and V2 were modulated by the chromatic light stimulus rather than color perception. Our findings support a transition in the ascending human ventral visual pathway, from a representation of the chromatic stimulus at the retina in early visual areas to responses that correspond to perceptually experienced colors in higher visual areas.

...

Vision is effortless. We recognize faces, navigate a crowded sidewalk, or judge the ripeness of strawberries with ease. These behaviors depend on the light entering the eyes, but what we experience follows from biological responses to light that result in seeing. A sharp distinction between the physical image in the eye versus the biologically rendered percept from the image is essential for understanding vision.

Historical theories of color vision failed to appreciate this distinction, leading to the mistaken assumption that color perception could be explained by the laws of physics. We now know that the colors we see follow from biological neural representations generated by light, but light itself carries no color.

You've not given any account of why you dismiss this meta-theory... — Isaac

It's inconsistent with the empirical evidence, and as I said, theories need to fit the facts, not the other way around. The empirical evidence is that external stimulation triggers brain activity that causes an internal, physiological experience. So either it does have a survival purpose or it's a deterministic effect of something else that does, such as a complex central nervous system.

So does the standard model, but without these holes. I'm asking why you choose the model with the holes (or why they are not, for you, holes at all). Why choose a model which creates this difficult to explain phenomena contrary to what we already have regarding evolved characteristics, when there appears to be no call for it? — Isaac

You just admitted to an internal, physiological sense of feeling pain. Why is it so difficult for you to extend this to other things, e.g. seeing colour?

You just seem so bewitched by the complexities of vision that you think it fundamentally different to other senses, like nociception. It isn't. It's just a different mode of experience caused by a different type of stimulus. When nociceptors are stimulated in certain ways, it triggers brain activity that causes the internal, physiological sense of feeling pain. When thermoreceptors are stimulated in certain ways, it triggers brain activity that causes the internal, physiological sense of feeling cold. When chemoreceptors are stimulated in certain ways, it triggers brain activity that causes the internal, physiological sense of tasting sweetness. When photoreceptors are stimulated in certain ways, it triggers brain activity that causes the internal, physiological sense of seeing red.

This is consistent with all the empirical evidence and explains why different people experience different things in response to the same external stimulus (slight differences with the central nervous system mean slight differences with the subsequent internal, physiological experience).

Exactly. so what is the equivalent situation with 'seeing red' to which you want to extend this physiological response?

Your argument so far seems to be that because pain is a physiological state, then so can 'red' be. But that's woefully inadequate as a theory. — Isaac

It’s not woefully inadequate. It explains colour blindness and synesthesia and why some people see the dress to be white and gold and others black and blue and why science doesn't describe the world as having “particles of redness” and is exactly what the experiment I referenced days ago concluded.

There is a physiological sense of seeing red, and it is that which immediately informs our cognition and drives our responses (e.g. how we describe things). This physiological sense is (usually) triggered by electromagnetic radiation stimulating the sense receptors in our eyes, and the nature of that radiation is determined by the arrangement of the electrons that make up the surface of some external object.

This is what the empirical evidence shows. Your armchair theory and word games don't trump empirical evidence.

Hmm so you were distinguishing neural alarm from bodily trauma? — bongo fury

Yes. The broken leg is the trauma. The brain activity (or the mental phenomena it causes) is the pain.

I'm suggesting the pain is the recognition of the trauma — bongo fury

And yet as I said we can recognise trauma without feeling pain (e.g. congenital insensitivity to pain) and we can feel pain without recognising trauma (e.g. headaches).

They suffered the trauma. My car suffers trauma. And pain, but only metaphorically. They, though, probably also had enough symbolic ability to associate it with trauma in general. Which is how we suffer pain literally. Perhaps. — bongo fury

We (usually) feel pain in response to trauma. They are two separate things.

The person with congenital insensitivity to pain can recognise the trauma of a broken leg without feeling any pain.

The rest of us can feel pain without recognising any trauma, e.g in the case of headaches or some internal injury (and there can be internal injuries that don’t cause pain too).

Pain and trauma just aren’t the same.

But then, applying that to the snooker balls, you're averse to saying that seeing the ball as red has something to do with associating it with red surfaces generally? For example by reaching for the word "red". I thought you might be. Slightly surprised that you reply with "sure".

If you're not totally averse to that, though, how about that being in pain is associating the bodily trauma in question with bodily trauma in general? For example by reaching for the word "pain". — bongo fury

I don’t need a language to be in pain. Pre-linguistic humans had headaches.

What I thought you were saying is that feeling pain can be reducible to brain states, and doesn’t require some non-physical supervenient phenomena. I’m not totally averse to that claim, although I’m not especially convinced by it either.