It would be helpful if colour realists explain which of these they believe:

1. “the apple is red” means “the apple reflects ~700nm light”
2. The apple is red because it reflects ~700nm light
3. The apple reflects ~700nm light because it is red

colored objects occur outside the body in a space independent of the mind. — NOS4A2

Objects outside the body just reflect different wavelengths of light. This light causes one type of colour sensation in humans and another type of colour sensation in dogs.

Color is a fiction. — NOS4A2

No it’s not, it just isn't what you claim it to be.

I don't see how it is useful to distort the picture with a fiction. — NOS4A2

Your reasoning is akin to arguing that because pain is not a mind-independent property of fire then it is not useful and a distortion and a fiction to feel pain when we put our hands in the fire.

The eagle has 20/5 eyesight, more rods and cones, and see much better. According to color factionalism they invent color, too, and somehow paint the images with their brain, but why would animals with such great sight distort their sight with color? — NOS4A2

It's clearly useful to visually distinguish objects which reflect 400nm light and objects which reflect 700nm light. Colour sensations is how we do that.

Take this for example:



It's not that either humans or dogs (or neither) is seeing the "correct" (mind-independent) colour when looking at an object that reflects 500nm light; it's just the case that 500nm light causes different colour sensations for humans and dogs.

No, just that it is possible to see thing more accurately, for instance if the world is without color, maybe it would better to see it without color. Why would a species need color? — NOS4A2

Is it possible to smell and taste things more accurately? Does the world contain smell and taste even when we're not smelling and tasting things?

if the world is without color then I suppose a scene of greys is what it must look like. — NOS4A2

You seem to be under the impression that there’s a way things look distinct from the way things look to us. That makes as much sense as saying that there’s a way things taste and smell and feel distinct from the way things taste and smell and feel to us.

Vision isn’t special.

I was including black, white, and grey as colours. But if we're excluding them and NOS4A2 is asking what the world looks like to someone with complete achromatopsia, then it would look black, white and grey.

I just mean seeing it without the sensation of color. What do you suppose it looks like? — NOS4A2

I don't even know what a colourless visual sensation could be, and so I think without colour sensations you'd just be blind.

Perhaps we would be able to numb the sensation of color like we could the sensation of pain, and see the world how it really looks. — NOS4A2

Not sure what you mean by "how it really looks", just as I wouldn't be sure what you'd mean by "how it really smells" or "how it really tastes".

Is the world outside your head without color in your view? — NOS4A2

Yes, and without smell and taste and pain.

Sorry - is your claim now that pain is also a fiction? :chin: — Banno

No, and nor is my claim that colour is a fiction. My claim is that pain and colour are sensations, and the fiction is that colour is not a sensation but a property of the ball.

And much like "stubbing one's toe is painful therefore pain is not a sensation" is a non sequitur, so too is "the ball is red therefore colour is not a sensation".

The ball is red. — Banno

And stubbing one's toe is painful, but pain is still a sensation. We've been over this so many times. Your reasoning is a non sequitur.

I'm trying to understand why it matters in this discussion whether our neuronal response to light is altered by our language skills. — Hanover

Maybe that's true, but I'm more arguing against those who seem to be saying that because we say such things as "the box is red" then it must be that the colour red is a property of the box and not a property of our bodies.

We see a red box and a blue box. The colour is the relevant visual difference between the two. I don't think that this visual difference has anything to do with language. The difference is entirely in how the boxes reflect light and then how our body responds to that light.

That is, if I see a cardinal, I don't just see the red of the bird, but I see the whole bird and I also have all sorts of thoughts about what that thing can do and what it is at the same time. I don't just get a raw feed of red. — Hanover

Sure, but I don't think all that other stuff has anything to do with the colour, and the discussion is about colour.

That Michael might allow interpretation of the external object by the sense organs alone and not allow it to also be interpreted by language just seems an odd limitation (if that's at all what he's even saying, as that doesn't seem correct). — Hanover

All I am saying is that a deaf illiterate mute can see the difference between a red box and a blue box. That visual distinction has nothing to do with language and everything to do with what the brain does (in response to what the eyes do in response to what the light does in response to what the box does).

Or for a more self-evident example, I can see the difference between two shades of red despite not having an individual name for each shade.

All this talk of language is utterly irrelevant.

[Michael] was never willing to try to explain how his conclusions followed from "the science." — Leontiskos

I have simply quoted what the scientists have said about colour. I'll do it again for you:

Colour is a sensation. — James Clerk Maxwell

For the Rays to speak properly are not coloured. In them there is nothing else than a certain power and disposition to stir up a sensation of this or that Colour. — Isaac Newton

Color is a psychological property of our visual experiences when we look at objects and lights, not a physical property of those objects or lights. — Stephen Palmer

As the SEP article on colour explains:

One of the major problems with color has to do with fitting what we seem to know about colors into what science (not only physics but the science of color vision) tells us about physical bodies and their qualities. It is this problem that historically has led the major physicists who have thought about color, to hold the view that physical objects do not actually have the colors we ordinarily and naturally take objects to possess.

If you disagree with the science then simply say so, but don't pretend that the science isn't saying what the science is saying. How much more explicit does the above need to be for you?

instead of making arguments for his position he would only ultimately make arguments from authority from "the science." — Leontiskos

Yes, because the scientists are the ones who have carried out the experiments to figure out how the world works, so they better know what they are talking about. You can't determine what colours are just by sitting in your room and using a priori reasoning.

The bolded word is where Michael oversteps. Things in the word, and the people around us, also have a say in what colours we see. — Banno

I haven't claimed otherwise. I have explicitly stated that ~700nm light is the usual cause of red colour experiences (because it is the usual cause of the brain activity that corresponds to red colour experiences).

When a shadow falls over a ball we do not say that the color of the ball has changed, because we differentiate our visual perception of the ball from the ball's color. — Leontiskos

The ball just has a surface layer of atoms with an electron configuration that absorbs and re-emits particular wavelengths of light; these wavelengths being causally responsible for the behaviour of the eye and in turn the brain and so the colour experienced.

Physics and neuroscience has been clear on this for a long time.

We might talk about the ball as having a colour but that's a fiction brought on by the brain's projection and the resulting (mistaken) naive colour realist view of the world.

But if seeing is using the eyes to perceive the environment, that isn’t sight. That’s all I’m saying. — NOS4A2

And as I've said, you're welcome to only use the verb "to see" in that sense if you like, but there's nothing wrong with the rest of us being more inclusive in how we use such language.

All that is required to have a visual experience is for there to be the appropriate neural activity in the visual cortex, and all that is required to have an auditory experience is for there to be the appropriate neural activity in the auditory cortex.

Most of the time this neural activity is a response to sensory stimulation of biological sense organs, but sometimes it is a response to other things, whether those be artificial sensory aids, drugs, sleep, or mental illness.

No amount of glasses can help the those with total blindness see, however. — NOS4A2

But other mechanisms such as a cortical visual prosthesis can help (or will be able to help in a few decades). Much like a cochlear implant helps where an ear trumpet can't.

They are seeing in the sense of having a visual experience but not seeing in the sense of responding to and being made aware of some appropriate external stimulus by way of their eyes, much like the schizophrenic is hearing in the sense of having an auditory experience but not hearing in the sense of responding to and being made aware of some appropriate external stimulus by way of their ears.

You've claimed that the "hears" in "hears voices" is just like the "hears" in ordinary predications about hearing — Leontiskos

No I haven't.

No, "hears voices" is a euphemism for "hallucinates." You are confusing yourself. — Leontiskos

I'm not confusing myself because I haven't claim that "hearing voices" isn't a euphemism for "hallucinate".

I am simply saying that it is ordinary in English to use the verbs "to see" and "to hear" in a much more inclusive manner than the more restricted sense that you and NOS4A2 insist on.

If they can hear, why do they have a cochlear implant? — NOS4A2

They hear because of the cochlear implant, much like I can see the words on the screen because of my glasses.

If they were reducible to the brain then everyone with a brain would be able to see and hear — Leontiskos

That doesn't follow.

It's not equivocation to say that the schizoprenic hears voices. That's just the ordinary way of describing the phenomenon.

Verbs like "to see" and "to hear" don't just refer to so-called "veridical" perception.

The deaf can't hear without a cochlear implant but can hear with one. It's quite simple.

The environmental stimulus and the means with which it interacts with a fully-functioning sensory organ is a large part of acts such as “seeing” and “hearing”, and ought not be confused with some other stimulus. Stimulating a brain with some of the methods indicated is just an artificial way to illicit some of the biological effects of an actual, natural stimulus, but is in fact not the same act. — NOS4A2

Why does that matter? It is still normal to describe someone with a cochlear implant as hearing things, and the same for those with an auditory brainstem implant.

If you only want to use the words “see” and “hear” for those with normally functioning sense organs then you do you, but it’s not wrong for the rest of us to be more inclusive with such language.

And perhaps more fittingly than a cochlear implant is an auditory brainstem implant.

One colour, or a bundle of colours, can look like another colour. — jkop

Colour is the look, not a wavelength of light (which you seem to be saying here). There is usually a correspondence between the two, but dreams, hallucinations, illusions, and cases such as the dress show that this correspondence doesn't always hold.

The blind can't see anything no matter what their brains are doing. — jkop

See cortical visual prostheses.

They're both elements for the emergence of red experience(s). — creativesoul

Although re-reading this, maybe I've misunderstood you. Are you saying that these are three distinct things?

1. 650-720nm light
2. The colour red
3. Red experiences

They're both elements for the emergence of red experience(s). — creativesoul

Sure, like getting stabbed or burnt or whatever are elements for the emergence of pain experience(s). But pain is nonetheless the experience. My claim is only that these colour experiences are our ordinary and everyday understanding of colours. When I think about the colour red I'm not thinking about atoms and electrons and photons or anything like that; I'm thinking about the experience.

Unless having already seen red is necessary for the illusion to work. — creativesoul

By this do you mean that 620-750nm light must have stimulated my eyes for me to see the colour red? Why do you think that? What’s the relationship between 650-720nm light and the colour red?

The arguments from illusion continue to pile up, as if the hight of the pile would make them more convincing. :roll: — jkop

Well, whether you’re convinced by it is irrelevant. What matters is that both a) I see a can of red Coke and b) the photo does not emit 620-750nm light are true. So one’s account of seeing the colour red cannot depend on 620-750nm light.

The factual explanation is that the colours we see are determined by what the brain is doing.

I use Discord for work so I avoid it otherwise.

Yep, is “color in a perceiver”? Well, sure if you open the skull to see the brain, it may appear grayish. But I suspect they are saying something rather metaphysical here, unverifiable. — Richard B

No, what they're saying is that the subject sees colours when there is activity in the V4 and VO1 areas of the visual cortex. Normally these areas are active in response to retinal stimulation by light, but that's incidental to seeing colours.

With regards to “grammatical fiction”, this is one of Wittgenstein ideas he expressed in PI 307,

“Are you not really a behaviorist in disguise? Aren’t you at the bottom really saying that everything except human behavior is a fiction?” - If I do speak of a fiction, then it is of a grammatical fiction.” — Richard B

And what does that have to do with anything I have said here, in particular that comment that you replied to? I am simply reporting that "the major physicists who have thought about color ... hold the view that physical objects do not actually have the colors we ordinarily and naturally take objects to possess" and that Maxwell has said "colour is a sensation".

Are you saying that Maxwell and most major physicists are wrong? Are you suggesting that somehow Wittgenstein's analysis of language can tell us about the physics of tomatoes and the physiology of visual experience, including colour experience?

Science studies stuff like brains, nerves, cells, molecules, etc… Not sensations and mental percepts. — Richard B

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).

He's said there's no colored things aside from mental percepts. — creativesoul

Not quite. I'm saying that colour and pain are percepts. We can still talk about tomatoes being colourful and stubbing one's toe being painful; we just have to interpret such talk according to something like dispositionalism, whereas you seem to be interpreting tomatoes being colourful according to something like naive realism, and it this naive realist interpretation that the science has disproven.

It is not the case that colour is a property of tomatoes but only that tomatoes have a surface that reflects ~700nm light, and this light happens to cause red percepts in most humans, with different organisms possibly having different colour percepts in response to that same light, e.g. see the difference between the visible spectrum for humans and dogs, or even the dress that some see to be white and gold and others as black and blue.

Feel free to keep your grammatical fiction, it may serve you well. — Richard B

I don't know what you're talking about. This has nothing to do grammar. This has to do with physics and physiology. Maxwell knew better than you about how the world works, especially when it comes to light. As he says, colour is a sensation.

We see our color percepts?

Yup. There's the Cartesian theatre. Homunculus lives on... — creativesoul

Feeling pain does not entail a "Cartesian theatre" or a homunculus, even though pain is a sensation, and seeing colours does not entail a "Cartesian theatre" or a homunculus, even though colour is a sensation.

You're arguing against a strawman.