You need to read up on the use-mention distinction. — Michael

Both the Indirect and Direct Realist directly perceive a tree in their minds. For both the Indirect and Direct Realist, the tree they perceive exists in the world. Note that Wittgenstein in Tractatus didn't specify where this world existed.

Example of "the tree is green" is true IFF the tree is green
"The tree is green" being in quotation marks is within language. The tree is green not being in quotation marks is in the world.

For the Indirect Realist, the world in which the tree exists is in their mind. For the Direct Realist, the world in which the tree exists is in a mind-independent world.

The meaning of the word "tree" has nothing to do with perception — Michael

If that were true, you would know the meaning of the word "mlima" even if you had never perceived one.

You could argue that even if you have never perceived a "mlima", it could be described to you, such that a "mlima" consists of "mwamba" and "theluji". But this doesn't solve the problem, in that you you cannot know the meaning of either "mwamba" or "theluji" until having perceived them. Sooner or later, meaning depends on perception. In Bertrand Russell's terms, knowledge by acquaintance.

For the Indirect Realist, the world in which the tree exists is in their mind. For the Direct Realist, the world in which the tree exists is in a mind-independent world. — RussellA

And that has nothing to do with the use of the word "tree". An illiterate deaf mute with no language can see a tree "in their mind". They just won't call it "tree".

If that were true, you would know the meaning of the word "mlima" even if you had never perceived one. — RussellA

No, it would mean that I could see something without having a word for it, which is true. I've seen many animals that I don't have a name for. I've smelt many different smells that I don't have different words for.

Sooner or later, meaning depends on perception. — RussellA

But perception doesn't depend on meaning. It might be that we can't have language without perception, but we can have perception without language.

An illiterate deaf mute with no language can see a tree "in their mind". They just won't call it "tree"...I've seen many animals that I don't have a name for...But perception doesn't depend on meaning — Michael

I agree, perception doesn't depend on meaning. There is an asymmetry between meaning and perception.

That seeing the colour red isn't just "reaching" for the word "red", and that colour is "in the head", not a property of external world objects.

That "there is literally [something] in the brain ... that corresponds to 'seeing red'". — Michael

In what way do you think the experiment supports that conclusion?

In what way do you think the experiment supports that conclusion? — Isaac

The very first two sentences of the summary:

There is no color in light. Color is in the perceiver, not the physical stimulus.

The very first sentence of the abstract:

Color is a perceptual construct that arises from neural processing in hierarchically organized cortical visual areas.

Further into the paper, under the heading "Representations of Subjective Color Experience":

This task aimed to exclude the involvement of higher cognitive processes, such as color naming, as it did not require any explicit judgment of the chromaticity of the stimulus.

The two claims of your I dispute are...

seeing the colour red isn't just "reaching" for the word "red", — Michael

there is literally [something] in the brain ... that corresponds to 'seeing red' — Michael

In what way does the experiment support those claims?

This task aimed to exclude the involvement of higher cognitive processes, such as color naming, as it did not require any explicit judgment of the chromaticity of the stimulus.

Seeing red isn't "reaching" for the word "red".

Color is a perceptual construct that arises from neural processing in hierarchically organized cortical visual areas.

Seeing red corresponds to particular brain activity.

"Ngoe" means at least a third of the picture is green? Or the picture is an odd number from the left? — Banno

Good first attempt. We are on the path to successful communication, definitely an iterative process. It's a bit like the Twenty Questions parlour game using deductive reasoning and creative thinking.

I will have to come up with five more pictures that excludes at least a third of the picture of the "ngoe" being green and excludes "ngoe" being an odd number.

As Wittgenstein said in para 32 of PI:
"Someone coming into a strange country will sometimes learn the language of the inhabitants from ostensive definitions that they give him; and he will often have to guess the meaning of these definitions; and will guess sometimes right, sometimes wrong."

This task aimed to exclude the involvement of higher cognitive processes, such as color naming, as it did not require any explicit judgment of the chromaticity of the stimulus.


Seeing red isn't "reaching" for the word "red". — Michael

The experiment tested the differential stimulation of the V4 and V01 regions. It found their activity was correlated with switches in sensory feedback suppression (classic switch rivalry), not changes in retinal chromatic stimulus.

It doesn't even mention seeing 'red'.

The section you quote is eliminating the possibility of yhr differentiation taking place in higher cortices (ie of V4 and V01 being faithful to retinal chromatic stimuli, but distinctions invoked later.

What the experiment shows is that V4 and V01 regions have differential responses unrelated to chromatic stimuli, but related to post V1 processing, further in the ventral stream.

It doesn't show that those differentiations are hard wired, or disconnected from cultural, environmental and linguistic influence. It doesn't even go into the construction of the priors which cause the differentiation, it simply locates them.

It doesn't even mention seeing 'red'. — Isaac

It mentions "colour percepts" and "colour perception" and "colour experience" and "colour we see".

Trying to argue that the paper doesn't support my position against yours because it doesn't mention the specific word "red" is a really poor attempt at gaslighting.

Again, the paper says "color is in the perceiver, not the physical stimulus" and "color is a perceptual construct that arises from neural processing". This explicitly favours my claims.

It mentions "colour percepts" and "colour perception" and "colour experience" and "colour we see". — Michael

It 'mentioning' those things is not sufficient to carry your argument. You need to understand what the paper is showing, its a technical subject. You can't just scan through it, find a few choice phrases and claim it proves your point.

It proves the location, within the ventral stream, of differential stimulation in neural clusters correlated with post V1 (non-retinal) signals.

It doesn't prove we 'experience red', or that 'red' is correlated with some neural state.

It doesn't prove we 'experience red', or that 'red' is correlated with some neural state. — Isaac

The experimenters seem to think so, given that they explicitly say "color is in the perceiver, not the physical stimulus" and "color is a perceptual construct that arises from neural processing" and "the present study ... examine[d] how subjective color experience is represented at each stage of the human ventral visual pathway".

The experimenters seem to think so, given that they explicitly say "color is in the perceiver, not the physical stimulus" and "color is a perceptual construct that arises from neural processing" and "the present study ... examine[d] how subjective color experience is represented at each stage of the human ventral visual pathway". — Michael

Again, none of those comments say that 'red' is in the brain. They're talking about colour (in this case, the neural responses associated with subjective states). 'Red' is a specific category, it is not synonymous with the mere activity of differentiation of colour.

What the experimenters are saying is that differentiation in colour is constructed from neural processes, not a faithful rendering of chromatic variation at the retina.

They are not saying that this neural construction is divided such as to represent 'red', or any other specific colour.

They are not saying that this neural construction is unaffected by culture, learning, and language, they don't even mention the factors associated with the construction of priors in these regions.

'Red' is a specific category — Isaac

Red is a colour, the word "red" refers to that colour. You seem to be making a use-mention error.

I can see five different reds here. I don't "reach" for five different words to describe what I see. That I see five different reds has nothing to do with language and everything to do with the raw subjective quality of my experience.

The private language argument is that such a thing cannot be understood in a coherent fashion. That there can be no private languages. That such a thing could not count as a language. — Banno

I agree.
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When the indirect realist says "I see the Earth", they are referring to the brown thing. When the direct realist says "I see the Earth", they are referring to the Earth. — Banno

This is misleading wording. To say that the Direct Realist is referring to the Earth is pre-judging that the Direct Realist is in fact correct in their belief that they are referring to the Earth.

Better wording would be: When the indirect realist says "I see the Earth" they believe they are directly seeing a representation of the Earth. When the direct realist says "I see the Earth", they believe they are directly seeing the Earth.

The question is, who is right.
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Summarising, what the private language argument shows is that one cannot construct a private language that is about one's private sensations. If indirect realism holds that what we see is not the world but a private model of the world, then one could not construct a language about that private model. — Banno

Indirect Realism doesn't need to construct a private language about one's private sensations. I can have the private sensation of a colour without the necessity of having to describe it in words, or of having a private language.



For example, the colour blue has been named "Blue" in a public performative act in the English language, and both Bill and Bob know this.

Note that the public word "blue" and the public colour blue are both objects in the world. For clarity, using the use-mention distinction, the blue in the object "blue" is a "mention", whilst the blue in the object with the colour blue is a "use".

It may be that when looking at the public colour blue, Bill has the private experience of yellow and Bob has the private experience of red, but both Bill and Bob have linked their private experience with the public word "blue", thereby allowing them to talk about objects in their shared world.

For example, if Bill asks Bob to pass over the "blue" object, even though Bill has the private experience of yellow and Bob has the private experience of red, Bob will successfully pass over the object Bill intends.

Indirect Realists can engage in a public social language without needing to be able to describe their private sensations.

Wittgenstein in para 293 in PI describes how everyone's private sensations may be different:
If I say of myself that it is only from my own case that I know what the word "pain" means—must I not say the same of other people too? And how can I generalize the one case so irresponsibly? Now someone tells me that he knows what pain is only from his own case!——Suppose everyone had a box with something in it: we call it a "beetle". No one can look into anyone else's box, and everyone says he knows what a beetle is only by looking at his beetle.—Here it would be quite possible for everyone to have something different in his box.

Wittgenstein continues that the private sensation has no place in a public language, and even if we do use the word "pain" in a public language it doesn't explain the sensation, only indicate that there is some kind of sensation
One might even imagine such a thing constantly changing.—But suppose the word "beetle" had a use in these people's language?—If so it would not be used as the name of a thing. The thing in the box has no place in the language-game at all; not even as a something: for the box might even be empty.—No, one can 'divide through' by the thing in the box; it cancels out, whatever it is.

Wittgenstein continues that the private sensation drops out of consideration within a public social language.
That is to say: if we construe the grammar of the expression of sensation on the model of 'object and designation' the object drops out of consideration as irrelevant.
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Treating this as a reductio, we do have language about the world, and therefore we talk about the world, and not about our private world-models. At least that form of indirect realism is wrong. — Banno

Indirect Realism accepts they have private sensations, but as argued by Wittgenstein in his beetle in the box analogy, such private sensations drop out of consideration within a public social language as irrelevant.

Wittgenstein's beetle in the box analogy justifies Indirect Realism.

I like the picture, although to be consistent with indirect realism and to prevent any real-world bias, it would be best not to colour the circle in the middle, and to invent a new word to replace the use of "blue". Perhaps this:




What does the word "grue" refer to? Wittgenstein would say some public thing, but I disagree. I'd say it refers to each person's subjective colour experience. It just so happens that due to subjective colour experiences being causally covariant with external stimulation (the same kind of light will trigger the same kind of experience), when Bill says "this is grue", Bob will agree, and they will both agree that things appear grue if the light they reflect has a wavelength of 500nm (because they're physicists and have measured the light reflected from that circle in between them).

Indirect Realism accepts they have private sensations, but as argued by Wittgenstein in his beetle in the box analogy, such private sensations drop out of consideration within a public social language as irrelevant. — RussellA

Agreed.

Wittgenstein's beetle in the box analogy justifies Indirect Realism. — RussellA

Don't you mean to say that Wittgenstein's beetle in the box analogy justifies talk of indirect realism in relation to the third-personal public concept of perception, but that this doesn't justify talk of indirect-realism in the case of one's own perception?

" 275. Look at the blue of the sky and say to yourself "How blue
the sky is!"—When you do it spontaneously—without philosophical
intentions—the idea never crosses your mind that this impression of
colour belongs only to you. And you have no hesitation in exclaiming
that to someone else. And if you point at anything as you say the
words you point at the sky. I am saying: you have not the feeling of
pointing-into-yourself, which often accompanies 'naming the sensa-
tion' when one is thinking about 'private language'. Nor do you think
that really you ought not to point to the colour with your hand, but
with your attention. "

In relation to your diagram above of the two people perceiving the same circle, consider the irrealist understanding of the beetle on the box:

Given that each individual only has access to his or her private colour, and uses his or her mother-tongue in a bespoke private fashion when referring to the "shared" circle, then what is the purpose of colouring in the shared circle?


According to Nelson Goodman (and quite possibly Wittgenstein), there doesn't exist a transcendental underlying fact with regards to the real colour of the shared circle. Following this line of thought further, one could even deny the very existence of a shared circle, as part of a strategy for defending direct-realism for all perceivers, without condemning any ensuing disagreements as amounting to contradiction.

I like the picture, although to be consistent with indirect realism and to prevent any real-word bias, it would be best not to colour the circle in the middle, and to invent a new word to replace the use of "blue". — Michael

It may be that when looking at the public colour blue, Bill has the private experience of yellow and Bob has the private experience of red, but both Bill and Bob have linked their private experience with the public word "blue", thereby allowing them to talk about objects in their shared world. — RussellA

Better yet, to be consistent with Wittgenstein's view of “private language” one should remove the colors inside the heads of the figures. There is no private language to articulate this. And maybe there is nothing there like the beetle. All we have is the public object in which we call “blue”. There is agreement in judgement and use, thus, a form of life.

to be consistent with indirect realism and to prevent any real-world bias, it would be best not to colour the circle in the middle — Michael

I agree that not colouring the circle would be more consistent with Direct Realism.

the same kind of light will trigger the same kind of experience — Michael

Yes, in practice this must be the case, as Bill and Bob are the product of the same 3.5 billion years of evolution, they share 99.9 % of their genetic makeup and they share the same common ancestor, Mitochondrial Eve.

Knowing these facts, Bill and Bob will agree they most likely have had the same private experience and therefore can sensibly name it "grue".

Better yet, to be consistent with Wittgenstein's view of “private language” one should remove the colors inside the heads of the figures. — Richard B

But we have private experiences, so removing the colours inside the heads is to deny a fact.

I agree that not colouring the circle would be more consistent with Direct Realism. — RussellA

Colouring the circle would be consistent with direct realism, specifically any direct realism that subscribes to colour primitivism. I believe most indirect realists would reject colour primitivism, and so not colouring the circle is consistent with indirect realism.

Yes, in practice this must be the case, as Bill and Bob are the product of the same 3.5 billion years of evolution, they share 99.9 % of their genetic makeup and they share the same common ancestor, Mitochondrial Eve.

Knowing these facts, Bill and Bob will agree they most likely have had the same private experience and therefore can sensibly name it "grue". — RussellA

That's not what I was getting at. Due to the fact that colour experiences are causally covariant with external stimulation, when Bill sees an object that reflects light with a wavelength of 500nm, he will always see it to be the colour shown inside his head in the picture, and when Bob sees an object that reflects light with a wavelength of 500nm, he will always see it to be the colour shown inside his head in the picture. And both Bill and Bob learn to use the word "grue" to describe the colour of objects which, they later learn, reflect light with a wavelength of 500nm.

So even though their private experiences of objects that reflect light with a wavelength of 500nm are different, they use the word "grue" in the same way. However, I would argue that the word "grue" refers to their private experiences, which are different, despite the shared public use. And I would argue that on the premise that, were I to be Bill and to learn of this picture, and that objects which reflect light with a wavelength of 500nm appear differently to Bob, I wouldn't say that grue appears differently to Bob, I would say that these objects don't appear grue to Bob; they appear a different colour.

Or to make it clearer, if we switch back to our ordinary colour terms, Bill wouldn't say that Bob sees blue differently, he'd say that Bob sees green instead of blue.

Better yet, to be consistent with Wittgenstein's view of “private language” one should remove the colors inside the heads of the figures. — Richard B

Wittgenstein p 293 PI
Suppose everyone had a box with something in it: we call it a "beetle". No one can look into anyone else's box, and everyone says he knows what a beetle is only by looking at his beetle.—Here it would be quite possible for everyone to have something different in his box.

Wittgenstein writes that everyone says there is something in their head, even if no one else knows what it is, so I cannot leave Bills' head blank. It may be the colour yellow, but it may not.

But we have private experiences, so removing the colours inside the heads is to deny a fact. — Michael

More like a grammatical fiction.

So it is OK to remove it.

We will all do just fine with our communication and understanding.

More like a grammatical fiction. — Richard B

It has nothing to do with grammar. Experience isn't language. I can be an illiterate, deafblind mute, and yet still feel pain.

It has nothing to do with grammar. Experience isn't language. I can be an illiterate, deafblind mute, and yet still feel pain. — Michael

Animals get around the world without language, and they certainly are experiencing the world.

But humans use language to understand and communicate what is going on in their experience. So, sometimes what we say makes senses and sometimes it does not.

This discussion is trying to get agreement on this distinction.

We may not succeed, but we can try.

Animals get around the world without language, and they certainly are experiencing the world.

But humans use language to understand and communicate what is going on in their experience. So, sometimes what we say makes senses and sometimes it does not. — Richard B

And so trying to say that language entails that we don't have private experiences is saying something that doesn't make sense. Any theory of language that entails this is demonstrably false.

Another approach to color and the like is to think how color terms play a role in the larger context of conversation. How is a claimmaking human different from a thermostat ? To murmur about consciousness or awareness is not so illuminating. What else can be done ?

The concepts for which inferential notions of content are least obviously appropriate are those associated with observable properties, such as colors. For the characteristic use of such concepts is precisely in making noninferential reports, such as "This ball is red." One of the most important lessons we can learn from Sellars' masterwork, "Empiricism and the Philosophy of Mind" (as from the Sense Certainty section of Hegel’s Phenomenology) is the inferentialist one that even such noninferential reports must be inferentially articulated. Without that requirement, we can't tell the difference between noninferential reporters and automatic machinery such as thermostats and photocells, which also have reliable dispositions to respond differentially to stimuli. What is the important difference between a thermostat that turns the furnace on when the temperature drops to 60 degrees, or a parrot trained to say "That's red," in the presence of red things, on the one hand, and a genuine noninferential reporter of those circumstances, on the other? Each classifies particular stimuli as being of a general kind, the kind, namely, that elicits a repeatable response of a certain sort. In the same sense, of course, a chunk of iron classifies its environment as being of one of two kinds, depending on whether it responds by rusting or not. It is easy, but uninformative, to say that what distinguishes reporters from reliable responders is awareness. In this use, the term is tied to the notion of understanding--the thermostat and the parrot don't understand their responses, those responses mean nothing to them, though they can mean something to us. We can add that the distinction wanted is that between merely responsive classification and specifically conceptual classification. The reporter must, as the parrot and thermostat do not, have the concept of temperature or cold. It is classifying under such a concept, something the reporter understands or grasps the meaning of, that makes the relevant difference.

It is at this point that Sellars introduces his central thought: that for a response to have conceptual content is just for it to play a role in the inferential game of making claims and giving and asking for reasons. To grasp or understand such a concept is to have practical mastery over the inferences it is involved in--to know, in the practical sense of being able to distinguish (a kind of know-how), what follows from the applicability of a concept, and what it follows from. The parrot doesn't treat "That's red" as incompatible with "That's green", nor as following from "That's scarlet" and entailing "That's colored." Insofar as the repeatable response is not, for the parrot, caught up in practical proprieties of inference and justification, and so of the making of further judgements, it is not a conceptual or a cognitive matter at all. — link

https://sites.pitt.edu/~rbrandom/Texts%20Mark%201%20p.html
"Semantic Inferentialism and Logical Expressivism"

A little more from the same source:

It follows immediately from such an inferential demarcation of the conceptual that in order to master any concepts, one must master many concepts. For grasp of one concept consists in mastery of at least some of its inferential relations to other concepts. Cognitively, grasp of just one concept is the sound of one hand clapping. Another consequence is that to be able to apply one concept noninferentially, one must be able to use others inferentially. For unless applying it can serve at least as a premise from which to draw inferential consequenceds, it is not functioning as a concept at all. So the idea that there could be an autonomous language game, one that could be played though one played no other, consisting entirely of noninferential reports (in the case Sellars is most concerned with in EPM, even of the current contents of one’s own mind) is a radical mistake.

Don't you mean to say that Wittgenstein's beetle in the box analogy justifies talk of indirect realism in relation to the third-personal public concept of perception, but that this doesn't justify talk of indirect-realism in the case of one's own perception? — sime

From the third-person, Wittgenstein's beetle in the box analogy shows that Bill and Bob can carry on a conversation even if they don't know what is in each other's mind. From the first-person, I could be Bill, and still be able to carry on a conversation with Bob.

consider the irrealist understanding of the beetle on the box — sime

Other than a general estrangement from our generally accepted sense of reality, I don't know Goodman's theory.

Given that each individual only has access to his or her private colour, and uses his or her mother-tongue in a bespoke private fashion when referring to the "shared" circle, then what is the purpose of colouring in the shared circle? — sime

I agree, henceforth I will remove the colour from the circle.

Following this line of thought further, one could even deny the very existence of a shared circle, as part of a strategy for defending direct-realism for all perceivers — sime

I agree, as my belief is in neutral monism, where in a mind-independent world there are only elementary particles, elementary forces and space-time. In a mind-independent world there are only parts and no wholes such as circles, trees, colours, etc.

Another approach to color and the like is to think how color terms play a role in the larger context of conversation. — green flag

Why? What is this obsession with language? Is it impossible for me to see that the sky and the grass are different colours without some language which includes a vocabulary to name such colours? I don't think so. The fact that we need language to talk about the colours we see is irrelevant to this discussion.