"Visual percepts" is again hollow. It means the patient discerned shapes. "Visual percepts" is hypostatisation. — Banno

"Visual percepts" is standard terminology in the neuroscience of perception.

See visual percepts evoked with an intracortical 96-channel microelectrode array inserted in human occipital cortex.

That sometimes one person sees blue where the other sees gold does not change this. — Banno

The nouns "blue" and "gold" in this sentence are referring to percepts. We see the same screen, we see the same light, but we don't see the same colours. Therefore the colours we see are not mind-independent properties of the screen or the light.

And the way the nouns "blue" and "gold" are being used in this sentence is the ordinary use of the word, and the things they refer to are what we ordinarily understand to be colours.

The words "white and gold" and "blue and black" are referring to both, the light being emitted by the dress and perceived by the viewer. — creativesoul

They aren't referring to both. When my colleague and I look at the photo of the dress we see different colours. The noun "colours" isn't referring to the light because we don't see different light; it's referring to our visual percepts, which are different.

This is the ordinary use of the noun, and what we ordinarily understand colours to be (and what the naive realist mistakes to be a mind-independent property of things). That we then might use the adjective "coloured" to describe the computer screen does not change this. Much like the noun "pain" refers to the mental percept even though the adjective "painful" describes things like stubbing one's toe.

Yep. Folk assume that colour words must refer, and that there must be a thing to which they refer, then get themselves all befuddled inventing things for them to refer to - "mental percepts" or "frequencies". — Banno

Sometimes words refer to things and states of affairs.

Unlike talk of "mental percepts" or "frequencies", talk of "dispositions" seems compatible with both ordinary language and science.

'Red' refers to an object's disposition to cause certain colour experiences. Its disposition is both ostensively and physically different from that referred to by 'green', for instance.

'Red' refers to an object's disposition to cause certain colour experiences. — jkop

The word "red" can be used to refer to an object's disposition to cause certain colour experiences, but they ordinarily refer to those certain colour experiences. Those colour experiences are what we ordinarily understand by colours, especially before we have any understanding of an object having a surface layer of atoms that reflects certain wavelengths of light.

When I think about the colour red, I think about the colour experience, not atoms reflecting light. When we describe the fact that some see a white and gold dress and others a black and blue dress, we are describing differences in colour experiences, not differences in objects reflecting light.

Referring to the SEP article you referenced before:

There is a group of views about color, which come under one or all of the labels, Color Irrealism, Color Eliminativism, Color Fictionalism. These titles are a little misleading, since some theorists also talk of there being colors in the sense of being dispositions to cause experiences of a characteristic type, and/or being (attributes in/of) sensations. Following our earlier discussion, in section 1.2, we may take it that what the color-Eliminativist is denying is that material objects and lights have colors of a certain kind: colors that we ordinarily and unreflectingly take the bodies to have.

...

Color Primitivist Realism is the view that there are in nature colors, as ordinarily understood, i.e., colors are simple intrinsic, non-relational, non-reducible, qualitative properties. They are qualitative features of the sort that stand in the characteristic relations of similarity and difference that mark the colors; they are not micro-structural properties or reflectances, or anything of the sort.

Our ordinary conception of colours is that colours are "simple intrinsic, non-relational, non-reducible, qualitative properties ... not micro-structural properties or reflectances".

The naive (color primitivist) realist falsely believes that these colours are mind-independent properties of objects, when in fact they are mental percepts.

This does not deny that we can use the adjective "red" to describe objects with certain micro-structural properties or reflectances; it only states that micro-structural properties or reflectances are not how we ordinarily understand colours, and not what we ordinarily refer to when we use the nouns "red" and "colour".

The OP had an interesting argument. He or she was saying that when we speak objectively about color, this is based on the assumption that we all have the same experience of the color spectrum, so that when I tell you to pick out blue light, you're able to do that because your experience of blue is the same as mine.

Then the OP points out that this assumption may be false. We may not be having similar experiences, although we've each learned to use "blue" to point to the same things. He or she is saying that since this uncertainty exists, we have to conclude that color experiences are unique to each individual.

So this is supposed to allow us to reject the argument that color is nothing beyond words used for pointing.

He or she is saying that since this uncertainty exists, we have to conclude that color experiences are unique to each individual. — frank

We certainly have evidence that colour experiences can differ between individuals; the dress is the obvious example, but also differences in color categorization manifested by males and females.

And speaking for myself, my left eye sees a slightly different colour (or hue) than my right eye.

But given that the macroscopic world is deterministic, and given that we have mostly the same kind of eyes and brains, it stands to reason that our colour experiences are broadly similar in most cases.

it stands to reason that our colour experiences are broadly similar in most cases. — Michael

It stands to reason. But there's a lurking problem with saying we have different color experiences. It implies an underlying standard, right? When we talk about the dress, we say some people see blue, and others see white. <-- That very statement is using color in an objective sense, as if there's a standard blue kept in a vault in Paris or something. It may be that we can't escape talking about color in objective terms at least to some extent. Maybe this comes back to the underlying requirement of communication itself. We have to assume a common ground. If it's not actually there, that's fine, but we have to behave as if it is. Do you agree with that?

I don't understand what you mean. Is there a "standard" pain? A "standard" pleasure? A "standard" sour taste?

I don't understand what you mean. Is there a "standard" pain? A "standard" pleasure? A "standard" sour taste? — Michael

The standard I'm talking about only shows up if we posit experiential dissonance. I ask Bill if he's having a stabbing pain. He says yes, but he's experiencing what Sally would call a dull pain.

So wait, we may not need a standard. We just evacuate all the terms of meaning and say we don't know what each person is experiencing?

That depends on what you mean by "know". If you mean certainty, then sure; we can't know what each person is experiencing. If you mean a true, justified belief, then we might know what each person is experiencing, e.g. if their experiences are in fact similar to our own. And again, given our similar biologies it stands to reason that our experiences are mostly similar.

That depends on what you mean by know. If you mean certainty, then sure; we can't know what each person is experiencing. If you mean a true, justified belief, then we might know what each person is experiencing, e.g. if their experiences are in fact similar to our own. — Michael

I'm saying if we look at the consequences of these two:

1. Everybody has similar experiences of color
2. Everybody has unique experiences of color

If it's 1, then color language can refer to both subjective and objective accounts. If it's 2, then color language is valuable for pointing to things, but not useful for talking about individual experiences.

Neither one allows us to dispense with talk of experience, though.

If it's 1, then color language can refer to both subjective and objective accounts. — frank

I haven't denied this. I've only argued that our ordinary, everyday understanding of colours is an understanding of colour experiences, not an understanding of atoms absorbing and re-emitting various wavelengths of light, and that our ordinary, everyday use of colour nouns refers to these colour experiences.

The use of the nouns "white", "gold", "black", and "blue" in the sentence "some see white and gold, others black and blue" when describing the photo of the dress is the ordinary, everyday use and is referring to differences in colour experiences, not differences in the computer screen's micro-structural properties or reflectances.

We just happen to naively and unreflectingly think of these colour experiences as being mind-independent properties of distal objects rather than mental percepts. And we're welcome to think of and talk about the world in that way if we like (and we often do), but we'd be wrong.

I haven't denied this. I've only argued that our ordinary, everyday understanding of colours is an understanding of colour experiences, not an understanding of atoms absorbing and re-emitting various wavelengths of light, and that our ordinary, everyday use of colour words refers to these colour experiences. — Michael

You're saying that color language is based on shared color experience. Our common ground in experience is what allows us to use color words to point to objects, right? We could call this color internalism, that each person has access to the same common ground from which language arises.

Someone could argue that since experience is inaccessible to the public, we don't know if we have common ground in experience. The only common ground we can verify is in the way we use language to accomplish things. This would be color externalism. It says language use is primary, and people borrow from that realm when they talk about their own experiences.

How do you answer the externalist?

The word "experiences" refers to experiences, so why can't the word "colours" refer to a subset of experiences?

And again, the use of the nouns "white", "gold", "black", and "blue" in the sentence "some see white and gold, others black and blue" when describing the photo of the dress is referring to differences in colour experiences, not differences in the computer screen's micro-structural properties or light emissions.

Do you agree or disagree?

How do we perceive a fire’s propensity to cause pain? By putting our hand in the fire and being hurt. In the case of colour, we look at the pen and see red. — Michael

I think all we can say is that when we have the perception of X and we perceive ourselves doing Y and we then experience Z that we can say Z follows from X and Y, but I don't see where the jump comes to explaining the external world.

That is, I see my hand (X) and then I see my hand go toward a perception of fire (Y ) and then I feel pain (Z). If I've started with the assumption that all the properties I perceive are mental creations, it just seems an item of faith to suggest there is an external reality composed of definitionally unknowable substances that underwrite all my perceptions. I say they are definitionally unknowable because if we assert that all properties are mental creations, it seems necessary to admit that a propertyless substance would be unknowable because what can I know other than properties?

I think it’s a little more than an assumption. Perhaps it’s the most rationally justified explanation. — Michael

It's certainly a built in assumption that generally goes unchallenged, but that would seem consistent with everything else we've said, which is that reality as perceived is a mental construct. That is, no one outside of philosophical circles goes around questioning if the flower is red or if the redness of the flower is a mental construct. If you're going open the door to questioning inherent beliefs, then why arbitrarily limit it? Why is it a rationally justified explanation to say the red is just in your head but it's not a rationally justified explanation to also say the entirety of the flower is just in your head?

I think it’s justified to claim that mind-independent chairs exist but that mind-independent pain doesn’t, and most would agree. — Michael

Except that the concept of a mind independent chair is incoherent. The only thing I know about chairs are its subjectively imposed properties, and so I have no idea what a true chair is.

Since physics studies what we perceive, it is the study of perceptions, just like all of science. It's for that reason you can't use physics as evidence of the external world.

All you're doing is assuming a dualistic universe of minds and bodies as your starting point , but I don't see how it's any more rational to assume idealism, materialism, or dualism. I defer to dualism as well, but that's either because it's a foundational construct in modern thought or it's something that we inherently accept as human beings, but if we're going to dig deeper into the question of what reality is composed of, I don't see how it survives any better than the alternatives.

In other news, if you put a capital Y in parenthesis, you'll create the thumbs up symbol. I learned that in the post above, so I had to insert a space after the Y to disable it. As in (Y ) versus (Y).

This shortcut will save hours. (Y)

If you're going open the door to questioning inherent beliefs, then why arbitrarily limit it? — Hanover

It's not arbitrary. I've just read up on some physics and neuroscience of perception. Atoms are mind-independent objects with mind-independent properties; their electrons absorb and re-emit various wavelengths of light, this light stimulates the rods and cones in the eyes, the eyes send signals to the brain, the neurons in the visual cortex are activated, giving rise to visual percepts, including colour percepts.

Those who see a white and gold dress have different colour percepts to those who see a black and blue dress, because different neurons in the visual cortex are activated.

I don't understand the aversion to what I am saying. Do you object to me saying that pain is a mental percept, not a mind-independent property of fire?

In other news, if you put a capital Y in parenthesis, you'll create the thumbs up symbol. — Hanover

Nuh uh.

ParenthesYs

The word "experiences" refers to experiences, so why can't the word "colours" refer to a subset of experiences? — Michael

Did you get the internalism vs externalism thing I explained? Color internalism is where experience is primary and language use emerges from common experience. That isn't verifiable.

Color externalism doesn't dictate how we speak, it just says that speech is primary because it's the only verifiable common ground.

And again, the use of the nouns "white", "gold", "black", and "blue" in the sentence "some see white and gold, others black and blue" when describing the photo of the dress is referring to differences in colour experiences, not differences in the computer screen's micro-structural properties or light emissions.

Do you agree or disagree? — Michael

Ugh... the "some see white, others see black" is philosophical spaghetti. It seems to be using white and black as objective entities, but it's simultaneously talking about subjectivity. We need to bury that sentence in the desert.

Ugh... the "some see white, others see black" is philosophical spaghetti. — frank

No, it's a scientific fact. There's a whole bunch of studies on the matter, such as Exploring the Determinants of Color Perception Using Thedress and Its Variants: The Role of Spatio-Chromatic Context, Chromatic Illumination, and Material–Light Interaction.

You seem to be letting some armchair philosophy (Wittgenstein?) get in the way of empirical evidence.

No, it's a scientific fact. There's a whole bunch of studies on the matter, such as Exploring the Determinants of Color Perception Using #Thedress and Its Variants: The Role of Spatio-Chromatic Context, Chromatic Illumination, and Material–Light Interaction. — Michael

Look at that article's abstract. It starts by talking about what people see, then it switches to what people reported seeing. It's straddling internalism and externalism, so it can't be used to support either side.

It talks about "different individuals view[ing] the same image ... reported it to be widely different colors" and "different individuals experienc[ing] different percepts when observing the same image of the dress".

Different percepts entail different reported colours because color nouns ordinarily refer to those percepts, not the light emitted by the computer screen.

It is a fact that I see white and gold and others see black and blue because it is a fact that I experience white and gold percepts and others experience black and blue percepts.

I'll have to think about this for a while.

Atoms are mind-independent objects with mind-independent properties; their electrons absorb and re-emit various wavelengths of light, this light stimulates the rods and cones in the eyes, the eyes send signals to the brain, the neurons in the visual cortex are activated, giving rise to visual percepts, including colour percepts. — Michael

What can you possibly know about an atom other than your perception of it?

If the redness is in my head and not the chair, why don't I say that about the shape as well? And why don't I keep going down the list until I realize that everything I know about the chair, including its atomic composition, is based upon my perceptions. Since I've already said my perceptions are mind creations, then I'm not talking about the atoms, but I'm talking about my perceptions, which is all I can ever talk about.

I get that my perceptions present to me a world where everything works together, like it appears that light bounces off chair objects that goes into my eyeballs and that makes me see chairs, but that doesn't mean that system is underwritten by an external reality of mysterious unknowable objects. That just means chairs look red when there's nothing inherently red about them and it might mean that eyes look like they receive light that gets interpreted, but that doesn't mean those perceptions of those events actually happened. If we can't say the red of the chair is in the chair, why are so sure your analysis of cones and rods isn't just mind created interpretations?

↪Michael I'll have to think about this for a while.
12 minutes ago — frank

It's been 12 minutes for God's sake. How much time do you need?

Your argument seems to be that if I claim that colours are mind-dependent then to be consistent I must claim that everything is mind-dependent. This is nonsensical reasoning. You might as well argue that if I claim that pain is mind-dependent then to be consistent I must claim that everything is mind-dependent.

It is a fact that some things are mind-dependent and some things aren't. Smells, tastes, colours, and pain are mind-dependent and atoms, apples, chairs, and pens aren't.

This is what physics and neuroscience show, and I trust their findings. Unless and until the science shows otherwise, I commit to these theses.

I've already referenced actual scientific studies, so I'll now reference something a little more casual:

Your brain is lying to you — colour is all in your head, and other ‘colourful’ facts

We think of colour as being a fundamental property of objects in life: green trees, blue sky, red apples. But that’s not how it works.

“What colour is not is part of our world,” says neuroscientist Beau Lotto. “Every colour that people see is actually inside their head … and the stimulus of colour, of course, is light.”

As light pours down on us from the sun, or from a lightbulb in our home, objects and surfaces absorb some wavelengths of light and reflect others. “The ones that are reflected then land onto our retina,” says Lotto. There, those reflected wavelengths are transformed into electrical signals to be interpreted by our brain.

So we don’t really “see” colour, but reflected light, as interpreted in our brain. “It’s a useful perception of our world, but it’s not an accurate perception of our world,” says Lotto.

I don't really care much for the philosopher who responds with "nuh uh, 'cause Wittgenstein says..."

Your argument seems to be that if I claim that colours are mind-dependent then to be consistent I must claim that everything is mind-dependent. This is nonsensical reasoning. You might as well argue that if I claim that pain is mind-dependent then to be consistent I must claim that everything is mind-dependent. — Michael

What I'm saying is that all that you know is mediated by the mind. There is no science that suggests otherwise. What that means is that you cannot trust your perceptions to be accurate reflections of reality because you don't know what your mind did to the incoming objects.

For example, an apple might be represented by some as sweetness, others as red, others as round, and others as a bound up mass of atoms. The reason we perceive it as we do might have nothing to do with truth, but perhaps just what maximizes our chances of survival or even something else.

Fire is experienced as red and as pain, both of which you know not to be properties of the fire. At some level you stop acknowledging that the perception isn't correlated to the object, but you declare it an inherent property. That seems to occur at the atomic level as you've presented it, where you just throw down and say I know there are atomic properties and they present as X,Y, and Z and they behave in a, b, c ways.

My question is why can you say you just know the subatomic particles move at certain speeds (for example) or that photons behave in certain ways if you're relying upon your mind mediated perceptions?

If we've established an unreliability of the mind as to how it correlates with reality, I just don't see how you can call an end to that unreliability at a certain level and then feel safe to claim that what you know about your perceptions are accurate and not blurred, manipulated, altered, and corrupted by the mind.

I didn't enter this discussion to question scientific realism and argue for idealism or solipsism or nihilism. I am simply explaining what the science shows. I trust the science over armchair philosophy.

And someone who argues that colours are mind-independent properties of objects at least accepts scientific realism to some extent; they don't claim that the world is all mind-dependent.

I didn't enter this discussion to question scientific realism and argue for idealism or solipsism or nihilism. I am simply explaining what the science shows. I trust the science. — Michael

Fair enough, but that sound less like philosophy and more just basic neuroscience and physics. I trust science as well for daily living, but I don't think it addresses the metaphysical questions except to the extent it admits to the corruption between the perception and the reality.