I always have. I just deny that colours are something other than mental percepts, just as I deny that pain is something other than a mental percept.

There are mind-independent properties that are causally responsible for colour percepts in the ordinary waking case, e.g. having a surface layer of atoms that reflects light with a wavelength of 700nm, but the colour percept and this surface layer of atoms are distinct, dissimilar, things. And as nouns, the words "red" and "colour" ordinarily refer to these percepts. This is what allows variations in colour perception to be a coherent concept.

As adjectives, the words "red" and "coloured" can describe distal objects, but this just means that they are causally responsible for the related colour percepts in the ordinary waking case.

This view contrasts with the naive colour realist who believes that as nouns the words "red" and "colour" refer to some mind-independent property that resembles the colour percept, and who often denies the existence of the colour percept entirely. This naive colour realism is inconsistent with physics and the neuroscience of perception.

SO are you saying you can have my "mental percepts"? — Banno

No, I'm saying that I can talk about them, just as I can talk about your thoughts even though I can't think them.

Maybe this will make my position clearer:

1. Colour percepts exist. They are what constitute (coloured) dreams and hallucinations.
2. These colour percepts also exist when awake and not hallucinating, e.g. when there is neural activity in the visual cortex in response to optical simulation by light.
3. When we ordinarily talk about colours we are, knowingly or not, referring to these colour percepts.

... if "red" is only a mental percept, then when you say “red” it refers to your mental percept, but when I say "red" it refers to my a mental percept. — Banno

How do you infer that? Pain is a mental percept, but when I use the word "pain" I am not referring only to my pain, just as when I use the words "thoughts" and "beliefs" I am not referring only to my thoughts and beliefs. I can refer to someone else's red just as easily as I can refer to someone else's pain and thoughts and beliefs.

It's true that I can't see their red or feel their pain or think their thoughts or believe their beliefs, but I can talk about them just fine.

For the - I think seventh or eighth time - the claim is not that being red or sour or smooth is in no part mental, but that it is not exclusively in your mind alone. — Banno

And, yet again, I accept that the apple is red, where "red" is an adjective and "the apple is red" means something like "the apple is causally responsible for a red visual percept".

But as a noun, colours are only mental percepts, because when I use the word "colour" I am referring to a mental percept and a mental percept is only a mental percept.

And being sour is a property of lemons... — Banno

As an adjective, yes, where this means that eating a lemon will elicit a sour-type mental percept.

We don't generally have the "mental percept" of "sour" in the absence of lemons or some other such food. — Banno

Well I do. My dreams and hallucinations aren't only visual and auditory; I smell and taste and feel.

So rather than us having to guess what you think is going on, set it out for us all. — Banno

I have done. Colours, smells, tastes, etc. are types of mental percepts, caused by neural activity in the appropriate cortexes in the brain. When this activity occurs when I'm asleep I'm dreaming. When this activity occurs when I'm awake, but in response to LSD, I'm hallucinating. When this activity occurs when I'm awake, and in response to ordinary external stimulation such as 700nm light reaching my eyes, I'm having a non-hallucinatory waking experience.

The naive view that then projects these mental percepts out into the wider world as mind-independent properties of things is mistaken.

And if I mean ""A sour taste is not only a 'mind-dependent' property of a lemon"? — Banno

Then you're wrong. Because a sour taste is a mental percept, caused by activity in the gustatory cortex in response to stimulation of the tongue by acidic chemicals.

If by "the lemon is sour" you just mean "[tasting] the lemon will cause a sour-type mental percept" then I agree.

But if by "the lemon is sour" you mean "a sour taste is a mind-independent property of the lemon" then I disagree. This is the naive view that is inconsistent with the science of perception.

And here we go again.

The berry is red. The berry is rough. The berry is sour.

These involve the berry. They are not purely mental. — Banno

And again, I addressed this in my distinction between adjectives and nouns above.

"Red" is not a mental property, whatever that might be. It's a colour. — Banno

Colours, like smells and tastes and pain, are mental percepts. They are what occur/exist when we dream and hallucinate – and also when having an ordinary waking experience.

What if ↪Mp202020 had chosen touch - would you be arguing that being smooth was a mental phenomena? — Banno

I address this in my distinction between adjectives and nouns in my post above.

I am pointing out that it is not only mental. — Banno

And I am pointing out that it is, just like pain.

Sour is used to refer to lemons, etc. all the time. — Count Timothy von Icarus

I address this in my distinction between adjectives and nouns in my post above.

Stubbing one's toe is not a "mental phenomena". — Banno

I didn't say it was.

Sure, in your somewhat illicit terms this might be so. What is shown is that being red is not private. That is, that there are red things is a part of our shared world. — Banno

There's ambiguity here with the English grammar.

The words "coloured" and "painful" are adjectives, the words "colour" and "pain" are nouns, and the word "red" is both an adjective and a noun.

As a noun, the words "colour", "pain", and "red" refer to mental percepts. As an adjective the words "coloured", "painful" and "red" can refer to distal objects, if by such use we mean that the distal objects are causally responsible for these mental percepts.

The existence of mental percepts caused by neural activity in the visual cortex in response to optical stimulation by light is a sufficient and well-supported account of colour (and other visual) experience.

The naive view that either denies the existence of mental percepts or mistakes mental percepts for some mind-independent property is wrong.

So what. — Banno

So the overwhelming agreement that some X is Y is not proof that Y is not a mental phenomenon.

Whether Y is "red" or "painful", there can be an overwhelming agreement that X is Y even if Y is a mental phenomenon.

That overwhelmingly folk agree that stubbing one's toe is painful does not show that pain is not a mental phenomenon.

Pain is a mental phenomenon, despite the overwhelming agreement on which things are painful.

There is simply no connection between your premise and your conclusion.

How could you know that? — Banno

"presume" doesn't mean "know".

That overwhelmingly folk agree on some things being red and others being not-red shows that red is not a private phenomena. — Banno

No it doesn't.

If colours are only a type of "mental phenomena" (think about that term...), then since your "mental phenomena" are quite distinct from mine, your red is quite different to mine. — Banno

Different token doesn't mean different type. Pain is a mental phenomenon, but presumably the pain I feel when I stub my toe isn't "quite different" to the pain you feel when you stub your toe.

Yet you can ask for the red pen and e happy with the result.

Red is therefore not a private experience. — Banno

As mentioned before, this is a non sequitur.

And you can say that words like "pain" and "sour" and "funny" refer to distal objects or their properties, but you'd be wrong.

But the Standard Model says absolutely nothing about trees, cats, bacteria, etc. — Count Timothy von Icarus

English words like "tree" and "cat" and "bacteria" refer to distal objects. English words like "position" and "momentum" refer to a distal object's properties. English words like "red" and "funny" and "sour" do not refer to distal objects or their properties but to the properties of conscious experience.

But it also makes no sense, for the reasons given, to say that red is no more than my-perception-of red. — Banno

I don't think anyone is suggesting that. The second and third paragraphs of the OP make it clear that he isn't saying that colours are just his personal experiences; he's only saying that colours – like smells and tastes and pain – are types of mental phenomena.

But are extension in space and motion likewise not in external objects? — Count Timothy von Icarus

The Standard Model certainly says so, so I accept that.

But what evidence is there of colours as something other than mental phenomena? We have empirical evidence of an object's surface layer of electrons reflecting certain wavelengths of light, but what of colour?

I haven't said anything about illusions or being "less real". I'm just saying that it's wrong to claim that colours are mind-independent properties of distal objects, just as it would be wrong to claim that smells and tastes and pain and being funny are mind-independent properties of distal objects.

All these things are real; it's just that they're not located where conscious experience isn't – and conscious experience does not extend beyond the brain.

Does claiming that pain only exists in the head entail that distal objects "don't really exist"? If not, then why would claiming that colour only exists in the head entail this?

Do you at the very least accept that colour percepts exist (e.g. when dreaming and hallucinating), and that these percepts are at least correlated to certain neural activity in the visual cortex?

But, I have the impression that you believe that all human beings have mental phenomena, regardless if they have dreams or not, hallucinations or not, etc — Richard B

Yes. Mental phenomena are either reducible to brain activity or are caused by brain activity. We dream/hallucinate/see (in colour) when the visual cortex is active. I see no reason to believe that dreaming and hallucinating involve mental phenomena but that ordinary waking experiences do not - that would seem like special pleading. Their only relevant difference is their cause.

Even if one wants to claim that colours are also a property of distal objects one cannot deny that colours are a property of mental phenomena, else one cannot make sense of dreaming and hallucinating in colour.

But then I deny that colours are properties of distal objects on the grounds that a) such things are unnecessary, given that colours as mental phenomena is sufficient, and that b) things like the Standard Model do not describe colours; they only describe various arrangements of atoms with a surface layer of electrons that reflect light at certain wavelengths.

And then the same principle for things like smells and tastes.

To put it another way, if I imagine a world full of beings who do not dream, hallucinate, etc, I do not need to posit mental phenomena for these being. — Richard B

Like a world of inorganic matter? Sure. What’s the relevance?

Do you really believe that the only way to make sense of dreams, hallucinations, etc is to posit mental phenomena. — Richard B

Yes. We don’t explain them by positing the direct acquaintance of some distal object. I don’t dream about dragons because my eyes are open and I’m looking at a dragon in my bedroom; I dream about dragons because my visual cortex is active when I sleep.

And it doesn’t happen under different conditions. That something novel occurs in one set of conditions doesn’t mean it applies to all. So using this one example while dismissing the rest is tantamount to pseudoscience. — NOS4A2

If the same distal object and proximal stimulus is responsible for different colour experiences then the colours experienced in this case are not properties of the distal object or proximal stimulus.

The fact that in other scenarios we have the same colour experiences neither a) refutes the above nor b) entails that the colours experienced in these other scenarios are properties of the distal object or proximal stimulus.

And as for less “artificial” scenarios, there is empirical evidence of sex differences in colour perception.

We hallucinate and dream, sure, but these are biological acts, not things worthy of their own noun phrase upon which we can ascribe properties. Properties are properties of things, not actions. The body is real, while what the body does is merely an account of what the body is doing from this time and that. — NOS4A2

I dream and hallucinate in colour. The colours I dream and hallucinate are properties of my dreams and hallucinations. Waking experiences are of the exact same kind - neural activity in the visual cortex - differing only in their cause and intensity.

White and gold or blue and black, for example, is unlikely to be the measurable properties of these objects in the brain. — NOS4A2

There are neural correlates of self-reported colour percepts. This is how neuroscientists are able to intentionally stimulate particular colour experiences in test subjects - they know which areas of the brain to excite to have the subject see red.

The distal object is a backlit screen, capable of shooting light in all sorts of different directions, or stopping light, sometimes through liquid crystal, etc. it seems to me such conditions can illicit different experiences. The dress itself did not illicit a different experience, as everyone saw it was blue and black upon viewing off the screen. This seems to me to suggest the conditions had much to do with it. — NOS4A2

And those conditions are the same for everyone; yet we have different colour experiences. So the point stands, and your comments here are irrelevant.

I can deny that they are properties of mental phenomena because mental phenomena do not exist. Again, nothing of the sort has ever been found, and until they have, it needs to be explained in terms of things that are actually there.

Subjective accounts of states of affairs are limited by the fact that one cannot be aware of what is actually occurring behind his own eyes, or in the brain, at any given moment, so treating them as accurate assessments of the biology seems to me absurd. — NOS4A2

We have evidence of neural correlates of consciousness. We have evidence of visual perception caused by direct neural stimulation.

None of what I am saying requires substance or property dualism. I am not saying that mental phenomena is non-physical. I am only saying that colour is a property of conscious experience and that conscious experience does not extend beyond the brain. This is perfectly consistent with conscious experience being reducible to neural activity.

Again, this is the only way to make sense of dreams, hallucinations, synesthesia, and differences in colour perception – all of which are real.

So while I can’t explain it in terms of naive realism, if it is strictly limited to artificial conditions, I don’t think it suggests phenomenology. — NOS4A2

But it's the same distal object and same proximal stimulus, yet a different colour experience. So how does that not suggest phenomenology? Any differences in colour experience must be explained by differences in the body or brain.

See also neuronal basis of perception:

In particular a stimulus can be perceptually suppressed for seconds or even minutes at a time: the image is projected into one of the observer's eyes but is invisible, not seen. In this manner the neural mechanisms that respond to the subjective percept rather than the physical stimulus can be isolated, permitting visual consciousness to be tracked in the brain.

...

In spite of the constant visual stimulus, observers consciously see the horizontal grating alternate every few seconds with the vertical one.

...

A number of fMRI experiments ... demonstrate quite conclusively that activity in the upper stages of the ventral pathway ... follow the percept and not the retinal stimulus.

It seems to me that the science is incredibly clear. Conscious experience is in the head. It is usually caused by and covariant with some external stimulus, but they are nonetheless distinct. There really is no place to deny it.

Even if you want to say that colours are also properties of mind-independent things, you simply cannot deny that they are (also) properties of mental phenomena. It is the only way to make sense of dreams, hallucinations, synesthesia, and variations in colour perception – all of which are real.

Some people describe the colour of the dress in this photo as black and blue, others as white and gold. They can be looking at the exact same photo on the exact same screen, their eyes reacting to the exact same wavelength of light. And yet they see different colours. This is explained by differences in the way their visual cortex behaves in response to optical stimulation.



And then manual stimulation of the appropriate areas of the visual cortex can cause people to see (coloured) things.

What more are you looking for?

It means that if you see a banana, you’re not seeing one in your head. I can record you looking at a banana, the location of both your head and the banana, and discern that nothing about the banana is in your head. — NOS4A2

I'm not saying that the banana is in my head. I'm saying that colours are in my head. They are a property of the visual percepts that are produced by activity in the visual cortex.

We’ve examined many brains and discovered no such thing. — NOS4A2

Sure we have. It's how we make sense of synesthesia, dreams, hallucinations, variations in colour perception, and so on. Visual phenomenology is distinct from distal objects and proximal stimuli. The second and third are often the causal explanation for the first, but that's all there is to it. Yours is the mistaken, naive view that projects the properties of the first onto the second.

No such thing exists in your head. — NOS4A2

It does.

I can take a picture of any object and it will undoubtedly show that it is outside your head — NOS4A2

I don't know what this means. But digital cameras work by measuring the energy of the light that strikes its sensors, using this to determine which of the pixels to turn on and at what intensity. Our brains probably work in the same sort of way, but with neurons in the visual cortex in lieu of phosphors on a screen.

Then how come the color of the percept isn’t outside the object if the light is outside the object? — NOS4A2

Your question makes no sense. Colour is a property of visual percepts and visual percepts exist inside my head. So what does "the colour of the percept isn't outside the object" even mean?

Wavelengths travel beyond the objects but the color never does. If the color is determined in part by the wavelength, how is it that if light bounces off an object at a certain wave length, we do not see the color anywhere outside of the object? — NOS4A2

Your question is misguided. Light stimulates our eyes, signals are sent to our brain, and the brain produces a visual percept with such qualities as shape and colour and depth. Our minds and conscious experiences don't literally extend beyond the body to encompass distal objects.

what is an example of a property of the chair that is in the chair itself even if my head (or nobody's head) never existed? — Hanover

The existence of its atoms and their propensity to reflect light at certain wavelengths.

The sorts of things described by the Standard Model are mind-independent. Other things like smells and tastes and colours and pain are mental phenomena, produced by brain activity in response to bodily stimulation.

So far the Republicans appear to be doing a rather bad job. — Echarmion

Well that's just a truism.

I kinda expected them to go all in on blaming her for their favourite topic - the border crisis — Echarmion

They're trying, but "Harris was never given the portfolio of border czar ... instead, Biden asked Harris to lead diplomatic efforts to reduce poverty, violence and corruption in Central America's Northern Triangle countries of Guatemala, Honduras and El Salvador, as well as engage with Mexico on the issue."

... and just treating her as a hapless nobody with no qualifications. — Echarmion

She's the Vice President, a former Senator, and the former Attorney General of California, so that won't work.

The reason a quality like “color” doesn't extend beyond the object is because it is a quality of the object, not the mind. The changes in color within objects and the differences between them are due to changes in the objects themselves, like when a banana turns green to yellow as the chlorophyll breaks down. — NOS4A2

When the structure of some object changes the wavelength of the light it reflects changes, and when the wavelength of the light changes the colour we see changes, because the colour we see is determined (at least in part) by the wavelength of the light that stimulates the eyes.

It doesn't then follow from this that colours are properties of these objects.

If you can be assured there is radiation, why can't you be sure there's red? — Hanover

This question is a little confusing. It's like asking "if you can be assured there is heat, why can't you be sure there's pain?"

I can be sure that there's red and that there's pain, but given our scientific understanding of physics and biology and psychology, it seems to be that red and pain are properties of minds, not properties of pens and fire.

The issue isn't over whether or not these properties exist, but over where in the world these properties exist. At least when it comes to colour, some appear to be locating them in the wrong place.

If "red" is just in your mind, when you ask for a red pen, how is it that the person you are asking hands you what you want? — Banno

I can ask someone to recommend a funny movie, and they can deliver, but I don't think it makes much sense to treat being funny as some mind-independent property of movies.

So the reasoning behind your question appears to be a non sequitur.

Would any of these things even matter to the core followers of his cult? — Christoffer

Nothing matters to his cult.

It's the moderates and independents that he's losing.

Why did his handlers even let him appear? — Wayfarer

Between this and his VP pick, I wonder if one or more of his advisors are intentionally trying to sabotage him.

I really don’t understand your confusion.

12 divided by 4 is 3.
10 divided by 4 is 2.5.
20 divided by 4 is 5.

3 and 5 are whole numbers and 2.5 isn’t. What else is there to say?