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.

This is where it gets interesting. How divergent can someone get with their apparent language of colors... — Richard B

Very divergent, e.g. in the case of synesthesia. Whereas most of us only see colours in response to light, some also see colours in response to sound (chromesthesia).

I start from a principle that features of human physiology evolved within a system where their cost did not exceed their survival benefit. In such a system, it would be practically impossible for the huge amount of calories mental processes consumes to be justified if all it did was detect internal states of the same system, I can't see the survival advantage.

So I'm asking you what the survival advantage is, or what your alternative meta-biological theory is. Without either I can't see how you can sustain the model with such glaring holes in it. — Isaac

Theories need to fit the facts, not the other way around, and it is a fact that the pain I feel isn't a property of the fire that causes me to feel pain.

So either there is a survival advantage to feeling pain, or feeling pain just happens to be a deterministic effect of something else that gives us a survival advantage (e.g. a complex brain that is able to effectively respond to stimulation).

Here's a model of pain...

1. an external state (light) stimulates a nociceptive nerve ending
2. that signal (among hundreds of others) travels through an hierarchical system of prediction engines which attempt to output a response appropriate to reducing the uncertainty of that external state (either by manipulating the external state by acting on it, or by refining the model by further focussed investigation)
3. one of those outputs is to alter the release rate of certain hormones which in turn influence the output of other prediction engines (shifting their priors slightly in favour of certain types of output)
4. This state of affairs, this hormone affected setup, if you were to report it (either to yourself, or to others) you would use the expression "feeling pain" to describe.

If the above were the case then how would it clash with what you claim here to "know" about your feeling pain. If the last thing your brain does, after going through the process of predicting the state of external nodes, is to render a self-report which you respond to as a 'feeling of pain', then how would you distinguish that from the actual functioning of your brain in response to external stimuli? — Isaac

I don't quite understand what you're trying to say here. It appears that this accepts that pain isn't a property of the external state that stimulates a nociceptive nerve ending, but is an "inner" state. I agree with the principle of that, but would extend it to other things, such as "seeing red", e.g.:

1. an external state stimulates the rods and cones in one's eyes
2. that signal (among hundreds of others) travels through an hierarchical system of prediction engines which attempt to output a response appropriate to reducing the uncertainty of that external state (either by manipulating the external state by acting on it, or by refining the model by further focussed investigation)
3. one of those outputs is to alter the release rate of certain hormones which in turn influence the output of other prediction engines (shifting their priors slightly in favour of certain types of output)
4. This state of affairs, this hormone affected setup, if you were to report it (either to yourself, or to others) you would use the expression "seeing red" to describe.

The key point is that red, like pain, isn't a property of the external stimulus.

I might go further and say that feeling pain and seeing red isn't just a "hormone affected setup" but is some supervenient mental phenomena, but as a first step we need to at least agree that red and pain aren't properties of external world objects before we can progress further.

Right. So what's the point of it?

If what we're sensing is not a property of anything external to the system doing the sensing, then why is that system sensing anything at all? Why is it only detecting properties it itself has made up? — Isaac

I don't understand your question. I don't know much about why putting my hand in the fire cases me to feel (in the former) sense pain. I just know that it does.

I'm not getting anything of the meta-biological framework your theory sits within.

This isn't my theory. It's what science has shown to be the case. You stimulate my nerves (or my brain) a certain way and I feel pain. That pain is in my head, not out in the world to discover.

Yes. Primarily 'feeling' is a term we use for multiple meanings, one of which is a summary of your mental state "how are you feeling today?". So "I feel pain" and "I feel the grass" have two different meanings. The former being used in the sense of describing a state of mind, the latter in the sense of touch-sensation.

You specifically wanted to talk about the problem of epistemology with regard to perception and not want to get caught up in semantics. Given the, it is only this latter sense of 'feel' we're interested in here, the one which is about you sensing the external world with your nervous system. — Isaac

The epistemological problem of perception concerns the relationship between the phenomenology of experience and the mind-independent properties of external world objects. The indirect realist argues that what we feel in the former sense is a mental representation of what we feel in the latter sense; that what we feel in the former sense is not a property of what we feel in the latter sense.

In the case of the dress, some people see in the former sense white and gold and others see in the former sense black and blue. The white and gold that I see in the former sense are not properties of the dress that I see in the latter sense, but are mental phenomena that result from brain activity in response to stimulation by the light reflected by the photo.

Given that it is what I see in the former sense that determines how I understand and describe what I see in the latter sense, and as what I see in the former sense is not a property of what I see in the latter sense, there is an epistemological problem of perception. That I can see in the former sense that the dress is white and gold tells me nothing about the dress I see in the latter sense (except the trivial fact that it causes me to see in the former sense white and gold).

But perhaps you need to have brain activity that succeeds in associating the red ball with red surfaces generally, and the blue ball with blue surfaces generally?

Having red or blue mental images in the brain, to meet that purpose, is kind of having a ghost in the machine.

Having the brain reach for suitable words or pictures, isn't. And, even better, it suggests a likely origin of our tendency to imagine that we accommodate the ghostly entities. — bongo fury

I'm not totally averse to saying that mental phenomena just is brain activity. What I'm averse to is the claim that being in pain has something to do with saying or thinking "I am in pain" or taking aspirin or performing some other activity that other people use to judge me to be in pain, or the claim that pain is a property of the external world object that causes me to feel pain.

But if you said, “I can see that one is green, and one is yellow”, can you be said to being seeing at all. — Richard B

Yes, I'm just not seeing what you're seeing. Much like with the case of some people seeing the dress to be white and gold and others seeing it to be black and blue.

To quote my favourite book (Dune):

Think you of the fact that a deaf person cannot hear. Then, what deafness may we not all possess? What senses do we lack that we cannot see and cannot hear another world all around us?

It's not unreasonable to assume that there is some organism in the universe that has some sense that we don't.

How would you go about learning what it's like to have such a sense? Is being told that apples are X and bananas are Y going to help you know what it means to be X or Y, and what it's like to experience X-ness and Y-ness?

I certainly don't think it would help me. I'd just know to repeat the supposed fact that apples are X and bananas are Y, which I think is all that ever happens in the case of the blind describing colour. They're told facts about colour by the sighted and repeat them. Much like me repeating facts about science that I don't actually understand at all.

Real understanding requires actually having such a sense.

Or to give a more grounded example, I don't know what it feels like to lose a child because I've never lost one (or had one). I've seen (on TV at least) people who have lost a child, and the public expression of their grief, but the claim that I therefore know how they feel is ridiculous, because I don't. And I never will unless I lose a child.

Bornblind people can tell you that an object can't be all red and all blue at the same time. — green flag

OK? I can tell you that a particle can't be both positively charged and negatively charged. It doesn't mean that I know what either of those things mean. They are quite literally meaningless terms for me. I just know of them, and that, whatever they are, they're incompatible, because that's what I've been told.

Repetition of facts isn't real understanding.

Wait a minute, though. So they learn what 'pain' means from other people ? But haven't you been saying (basically) that it's label on something internal ? That it refers to a state of an immaterial ghost ?
But how could a parent ever check if the child was labelling states of the ghost correctly ? The whole theory of the ghost as the ground of meaning is like the idea of phlogiston or the ether. It plays no real role. 'Pain' is a mark or noise that a little primate might make to be comforted or medicated. — green flag

I burn my hand. I feel pain. I am told by my parents that I must be in pain. I learn to associate the word "pain" with the feeling.

I don't understand what's difficult to understand about this.

Imagine a person is not acting and still insists, while smiling and laughing, that they are suffering 'excruciating pain.' If they 'have' to be acting or not understanding English, that just supports my point. — green flag

I don't see how it supports your point. As I said before, nobody would ever learn to associate the word "pain" with the feeling that causes them to smile and laugh. If anything our common use of the word "pain" supports my assumption that other people feel the same thing I do, and is how I am able to talk about and understand their private experiences. Even though they're radically private, they're not radically different.

Although I admit it might not be evidence that they feel the same thing I do; it's only evidence that what they feel causes them to react in the same way as me.

If you stopped at the light because you saw that it was red, seeing was the cause and stopping was the effect. How can the effect be part of the cause? That appears to be an abuse of language. — frank

Exactly that. I take aspirin because I'm in pain. It's not that me being in pain just is me taking aspirin.

You seem to be hinting at truth apart from language, but to me that's a round square. Statements are true sometimes. Or we take them to be true...to express what is the case, etc. — green flag

Not really. I'm simply saying that it can be appropriate to say one thing, given the evidence available to us, even though that thing is false.

If someone is crying it is appropriate to say that they must be sad. But we're wrong, because they're just acting.

What if we cut out the middle man ? 'Seeing red' is acting accordingly, etc. We wise others decide that you saw red because you stopped at the light. (Stopping at the light is part of seeing red.) — green flag

This is the kind of Wittgensteinian nonsense that I just don't get.

You put a red ball and a blue ball in front of me. I can see that one is red and one is blue. I don't need to do or say anything that you can interpret as me "seeing red" or "seeing blue". Me seeing red and seeing blue has nothing to do with you or your judgement. It only has something to do with me and what's going on in my head.

But I insist that we have public criteria for when it's correct to assert someone is in pain. — green flag

This is misleading phrasing. "Correct" in this sense means "appropriate" or "justified", not "true".

But on your view we couldn't say that. Because your view allows for that person's pain to be what we call ecstasy. — green flag

Not really. If someone feels what I call "ecstasy" in response to cutting or burning their hand, they'd never learn to use the word "pain" to refer to it. If such a child burns their hand and laughs, they won't be told by their parents "you must be in pain", they'd be asked "why are you laughing?".

Here's what doesn't make sense : "It really hurts to chew broken glass, so he stuffed another handful in his mouth." — green flag

Ambiguous use of the word "sense" here. The sentence is meaningful and internally consistent, even though we might not understand the motivation of such a person (maybe he's a masochist, or filming a new season of Jackass).

"You can't know if my red is your red because seeing is private experience." — green flag

Which is true. I know for a fact that the term "red" covers a variety of different shades. I don't know that what I see to be one shade of red is what you see to be another shade of red.

And by extension, I don't know that what you see to be shades of red is what I see to be shades of orange, or green, or blue.