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

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

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).

'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.

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".

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.

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.

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.

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.

What is it you think that experiment is demonstrating which contradicts what I've said? — Isaac

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 (whether light or the apple).

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

Well, for a start both those claims are demonstrably false. learning new things about an object changes the priors our lower hierarchy cortices use to process sensory inputs which changes the resultant responses, including post hoc construction of the 'experience'. This has been demonstrated over an over again in the literature.

But notwithstanding that, the claim isn't that you'll see it differently, the claim is about seeing 'red'. 'Red' is a cultural division of a continuous colour spectrum. No one can see 'red' who doesn't know that category. they just see. Light stimulates the retina and the brain responds. That response can be of almost any type depending on priors (and to a small extent 'hard-wiring'). None of that response answers to 'seeing red'. there is literally nothing in the brain (and people have looked really hard) that corresponds to 'seeing red'.

All we have neurologically is photons hitting retinas and behavioural responses in a constant cycle. they differ between people and there's no grounds at all for identifying any of those responses as being 'seeing red'. — Isaac

Neural representations of perceptual color experience in the human ventral visual pathway

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.

...

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.

Learning that the tongue contains gustatory cells that respond to the chemicals in food, and that sugar tastes sweet because of its hydrogen bonds, doesn't change the taste of sugar. And learning the name of this animal doesn't change how it looks. And in fact with this animal, being able to see it doesn't involve "reaching" for whatever word names it (given that I can see it but don't know its name), and so too seeing the colour red doesn't involve "reaching" for the word "red".

You really are making such bizarre claims.

Exactly, that is what an Indirect Realist would say. — RussellA

There's no meaningful difference between these two phrases:

1. In the absence of any English speaker the word "tree" wouldn't exist, but the object currently referred to by the word "tree" would exist.

2. In the absence of any English speaker the word "tree" wouldn't exist, but the tree would exist.

The second, however, is a more natural way of talking, and so should be preferred.

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

As I believe in the ontology of Neutral Monism, where reality consists of elementary particles and elementary forces in space-time, the meaning of the word tree is fundamental to my philosophical understanding. — RussellA

The meaning of the word "tree" has nothing to do with perception. Seeing and hearing and feeling has nothing to do with language. Blind people aren't blind because they lack the right vocabulary; they're blind because their eyes don't work.

I don't know the name of this animal. I can still see it. It still exists. Whether or not I see it directly or indirectly is the topic of this discussion, and the answer to that depends on the nature of experience and its relation to external world objects, and that has nothing to do with how we talk. We can consider ourselves to be illiterate mutes just for the sake of argument. Presumably we'd still see things (and if we're considering sight specifically, throw in the assumption that we're deaf, too).

However, in the absence of any English speaker, the word "tree" would not exist, and "trees" would not exist in the world. — RussellA

Use-mention error.

In the absence of any English speaker the word "tree" wouldn't exist, but the object currently referred to by the word "tree" would exist.

Or, more simply, that thing over there is a tree, and that thing over there would continue to exist even if we stopped using the word "tree". It might no longer be called a tree, but it would still exist. And newly discovered animals don't come into existence only when we name them. They exist, and are what they are, even before we call them something.

There's a very peculiar obsession with language in this discussion. It's not clear to me what English grammar and vocabulary has to do with perception. Are people asserting a very extreme version of the Sapir–Whorf hypothesis?

If this is true, it's not a discovery about seeing but only about the grammar of 'see.' — green flag

Yes, that's where much of this discussion gets lost; in irrelevant arguments about grammar.

We use the word "see" in (at least) two slightly different ways, with direct and indirect realists having a preference for one or the other, and it distracts from the more pertinent epistemological problem of perception (the relationship between phenomenology and the mind-independent nature of things).

We can talk about the schizophrenic hearing voices (that aren't there), or we can talk about the schizophrenic not "actually" hearing voices (because there aren't any). The idea that one or the other is in some sense the "correct" way of talking, or says something about the philosophy or science of perception, is mistaken. They're just different ways of talking that have nothing to do with the actual disagreement between direct and indirect realists.

It means that I'll reach for the word "red" if asked to describe the colour.

...

I didn't say it happened in a vacuum. there are all sorts of other cognitive activities resultant from seeing an apple, but none of them have anything to do with 'red'. 'Red' is a word, so it is resultant of activity in my language centres. — Isaac

People can see red even if they don't have a language to describe colour. They can feel pain even if they don't have a language to describe pain. They can smell roses even if they don't have a language to describe smells.

In fact smells are a good example this. I can smell so many different things and yet I don't have words to describe each kind of smell. There's no thinking involved in this. I don't think, "it's smell X" or "it's smell Y". I just smell.

The meanings of words change. Before there was a scientific test for what we should call "red" it would have been more a community decision - to be 'red' was simply to be a member of that group of things decreed to be 'red', but nowadays, I suspect people will defer to the scientific measurement. — Isaac

What a young child means when they say that an apple is red is exactly what I mean when I say that an apple is red, but I know about electromagnetic radiation and the young child doesn't. It just isn't the case that when I say "(I see that) the apple is red" that I am saying anything about quantum mechanics, and it's certainly not the case that when I see that the apple is red (but say nothing) that I am thinking anything about quantum mechanics. I'm just seeing.

To reiterate, in one version of the argument the indirect realist claims what we see is a model of the tree — Banno

It’s just another way of talking. It’s like saying that I feel pain rather than saying I feel a knife stabbing me. That sensation of pain is feeling the knife stabbing me. But pain is a property of the experience, a mental phenomena, not a property of the knife, and we do in fact feel pain. There’s no suggestion of a homunculus here. Why it would be any different for sight is lost on me.

Try talking instead about the apple "appearing" smooth. — Banno

Yes, I’ve mentioned this before. There’s something peculiar about sight that I think is more susceptible to direct realist thinking than other senses might be. Does the fact that you would feel cold were you to be placed in the Arctic but that a polar bear doesn’t show either that you can sense the cold that’s there better than the bear, or that you mistakingly sense some cold that isn’t there? Or is it just the case that your body is such that, in such temperatures, you feel cold? I think the latter. And I think that things like colour are no different in principle. It’s just a different mode of experience caused by a different type of stimulus.

So injustice is beneficial so long as it suits your concerns. I cannot abide by that, myself. — NOS4A2

And I cannot abide by the claim that you being able to own a gun is more important than a child being safer from gun violence.

I believe what drives actions like these is an incredible resentment, hatred, a desire for revenge, etc.

Is no one but me interested in what exactly causes such an amount of hate to manifest in relatively young children?

That's not normal where I'm from. — Tzeentch

But is there more resentment and hatred in Americans than in, say, Brits? Or is it the same, and it’s just that Americans have more guns and so more violent means to express their resentment and hatred?

It’s certainly important to consider why people do what they do, but it’s also important to consider what enables them to do what they do. And it might be easier and faster to limit their opportunities than to limit their motivations.

You don't think kids committing mass murders is a mental health issue?

Ok then. — Tzeentch

If countries with the same rate of mental health issues have a lower rate of mass shootings then something other than mental health must explain the higher rate of mass shootings. One explanation is the higher rate of gun ownership. Another is that there is something almost unique about US culture and upbringing that people are more violent than in more civilised countries. Perhaps their obsession with gun ownership fuels that.

I’m pretty sure all these school shooters know that the police are going to kill them. A lot of them even kill themselves. The threat of ”mutually assured destruction” might work for international relations, but it won’t against the types of person who will mindlesly kill innocents.

Perhaps. But I doubt if everyone owned a gun people would start shooting each other. — NOS4A2

Not everyone would start shooting each other, but more would. Or do you think that if more people have guns then fewer people would use them?

Then why don’t you put everyone in prison? You’ll eliminate violence entirely. — NOS4A2

Because that's a far greater injustice than the injustice it tries to solve.

I'm against the death penalty because of the possibility of false convictions, and killing innocent people is a greater injustice than whatever injustice would follow from not killing guilty people.

I'm not against taking away people's guns, because taking away good people's guns isn't a greater injustice than the injustice that would follow from not taking away bad people's guns.

It's a utilitarian approach to choose between injustices. There's always going to be injustice, that's just a fact of life. A good society is one that knows how to weigh one injustice against another.

That’s why utilitarianism is unjust. You’ll punish people for things they haven’t done. — NOS4A2

Often a necessary price we have to pay to live in a safer society. Judges and juries are not infallible. Sometimes they imprison innocent people. That's an unfortunate injustice that we just have to accept.

The same, I would say, with taking away people's guns. It's a necessary injustice to limit the far greater injustice of innocent children being killed at school.

Yes I believe I ought to be able to defend myself with whatever I want. — NOS4A2

On what grounds? You have a basic human right to defend yourself with the most powerful means available?

I am entitled to my guns because I own them. — NOS4A2

So your argument against gun control is that it is unjust for the government to take away your property (without good reason)?

Firstly, the utilitarian concerns I mentioned before might be good reasons to take away your guns. Given that we don't live in the Minority Report and can't know who is going to shoot someone in the future, we ought to err on the side of caution, assume that anyone could be a potential shooter, and so take guns from everyone.

Secondly, what about only making it illegal to sell or trade guns and bullets? You're entitled to keep what guns and ammo you own, but you're not entitled to come into possession of more. Would that be just?

I have a basic human right to defend my life, liberty, and property, and owning weapons extends from this right. — NOS4A2

Are you saying that because you have the right to defend yourself, you have the right to defend yourself with guns? What about with dynamite or with tanks or with fighter jets?

It’s unjust because they are mine, I am entitled to them, and I have done nothing to justify taking them away. — NOS4A2

Why are you entitled to guns? Do you have a basic human right to own them?

It’s unjust to ban my weapons if I didn’t shoot anyone or do not intend to. — NOS4A2

Why is it unjust? Is it unjust because you have a basic human right to own a gun?

Why can I not own a firearm if I didn’t shoot anyone or do not intend to? — NOS4A2

Asking me a question doesn't answer mine. You said that banning guns is unjust, and prior to that referenced basic human rights. So are you saying that we have a basic human right to own guns? If not then that comment was a non sequitur.

Banning guns is unjust. — NOS4A2

How so? We have a basic human right to own firearms?

Before that it was car accidents. Maybe we should ban cars. — NOS4A2

Banning cars would cause insurmountable damage to the country and the economy, and so car accidents are an unfortunate price we have to be willing to pay.

I can't say anything of the kind about gun ownership.

Most mass shooters are male. — NOS4A2

So how does this being a transgender shooter suggest that it isn't uncharacteristic? I'm pretty sure transgender mass shooters are a significant minority.

Apples appearing red, just means that I think apples are red. — Isaac

There's more to experience than just rational thought. Seeing and feeling and tasting aren't just cases of thinking.

But what does it mean to think that apples are red? You suggested before that to be red is to have a surface that reflects light with a wavelength of 700nm, so to think that apples are red is to think that apples have a surface that reflects light with a wavelength of 700nm? How does that make sense given that people saw, and thought, that apples were red long before they even had the concept of electromagnetic radiation?

There's no separate thing 'the appearance of red' with which we might mistake the property of the apple. — Isaac

You think that they're red because they appear red. You "reaching" for the word "red" to describe apples isn't just something that happens in a vacuum. And presumably you're not a p-zombie that just mindlessly responds to stimulation by spouting out words.

It would indeed since a 'red appearance' is utter nonsense. — Isaac

You don't think that apples appear to be red?

Why is it a mistake? If an object can have the property 'reflects light with a wavelength of 700nm' why can't we call that property "red"? — Isaac

You can call it anything you like. But it would be fallacious to conflate redness in this sense with redness as the appearance. We'll just be using the word "red" to mean two different, albeit causally connected, things.

Can an apple not be both red and 'reflective of 400nm wavelengths'? — Isaac

I'm not saying anything about what they can or can't have. I'm saying something about what they do and don't have. And there's no indication that an apple has anything like a sui generis property of "redness", equivalent to a red appearance. The evidence is just that objects reflect light at certain wavelengths, and that when light with a wavelength of 700nm stimulates the eyes of the typical human then the object appears red to that person (and when it stimulates the eyes of the atypical human then the object appears orange, or green, or whatever to that person).

It's a mistake to then project this coloured appearance onto the external world. It's the naive view that modern science has refuted.

Surely things must appear to the scientists to be the way they now report them to be; otherwise why are they reporting them to be that way?

Things are not as they once appeared. — Isaac

I meant specifically that things aren't as they appear to ordinary human perception, e.g. that objects aren't coloured, in the colour primitivist sense that was believed by direct realists. Objects only appear coloured because of the way the human body responds to stimulation by electromagnetic radiation.

it would be really helpful if people would state what definition of "direct realism" and "indirect realism" they are using when they are posting. — prothero

I'll take a rather simple definition from the problem of perception:

In the context of the Problem of Perception, these cases are usually distinguished as follows: a veridical experience is an experience in which an ordinary object is perceived, and where the object appears as it is; an illusory experience is an experience in which an ordinary object is perceived, and where the object appears other than it is; a hallucination is an experience which seems to the subject exactly like a veridical perception of an ordinary object but where there is no such perceived or presented object.

The direct realist view is the view that things are as they appear. Directness is their explanation of how this is the case. It is how they resolve the epistemological problem of perception. Things appear as they are because perception is direct.

The indirect realist view is the view that things might not be as they appear. Indirectness is their explanation of why this is the case. It is why there is an epistemological problem of perception. Things might not appear as they are because perception is indirect.

Semantic direct realism, as Howard Robinson calls it, seems to accept the indirect realist's view that things might not be as they appear, but wants to call this direct perception anyway, even though directness was used to explain how things appear as they are.

I really don't care if you want to describe perception as "seeing a tree" or "seeing the appearance of a tree". It makes no real difference. The relevant fact is that an object's appearance is not its mind-independent nature, and that it is an object's appearance rather than its mind-independent nature that is the direct object of rational thought, and so there is an epistemological problem of perception. Seeing something might not show us what it’s like when we don’t see it. And I think modern science has proven that things aren't as they appear.

A transgender shooter. It might not be as uncharacteristic as we’d like to admit. — NOS4A2

What do you mean?

The direct realist says that seeing is constructing a model of the tree. The process of construction is part of the "self" doing the seeing. — Banno

In fact I think this is a prime example of the problem. The indirect realist will agree with this, and say that this model is a representation of the tree, and that it is this model that (directly) informs our understanding. You appear to be describing indirect realism, but calling it direct realism.

Arguing over the semantics of whether this should be called "seeing a tree" or "seeing a model of a tree" is a red herring. It's like arguing over whether I'm talking to my parents (over the phone) or talking to my phone, or arguing over whether I feel the fire or feel the burning pain in my hand. They're just different ways of talking that make no real difference to the underlying philosophical consideration.

And here's the reason this topic is recalcitrant. Both sides describe the situation in almost the same terms, but mean slightly different things in each case, talking past each other using much the same language. — Banno

I make much the same point every time this discussion happens. My earlier comments here and here get to the heart of the issue.

Arguing over whether we see external objects or see some mental image of external objects doesn't address the epistemological problem of perception. The concern is the relationship between the phenomenology of experience and the mind-independent properties of external objects.

According to (phenomenological) direct realism, I see the apple to be red because colour primitivism is the case, and when I see the apple its mind-independent properties are actually present in my experience.

According to indirect realism, I see the apple to be red because its mind-independent properties are such that it reflects light with a wavelength of ~700 nm, and light at that wavelength, when stimulating my eyes and central nervous system, triggers the experience of the colour red -- and this redness is a property of my experience, not a property of the apple (much like pain is a property of my experience, not a property of the fist that hits me). Redness is a "mental representation" of a surface that reflects light at a particular wavelength.