A few centuries ago, there may well have been people in Africa (the Himba) who did not see blue at that time, due to natural selection:
http://www.rationalskepticism.org/post1478006.html?hilit=Himba#p1465403
These days, they do see blue, but probably only due to interbreeding with the Hereros (see the linked posts).

GrahamH wrote:It would help is you watched the video.
https://youtu.be/VIg5HkyauoY?t=19s for rainbows without blue. It's only 19s in FFS.

...

I did watch much of it, but found it not to be very enlightening.

Repeated post. Sorry.

romansh wrote:

GrahamH wrote:

romansh wrote:

GrahamH wrote:I think I'm with SoS on this. 'physical colour', the physics of light and bus and visual system is a reliable discriminator of colour. The 'my red is like your red' spook inner mental world stuff is probably illusion. The bus isn't an illusion.

Well I agree our perception of 'colour' is a reasonable discriminator of colour (or at least photon wavelengths) . That was never an issue.

Sorry, I'm lost. I don't know what you are asking.

In this post I was not asking anything. Just agreeing that our vision has a reasonable colour discrimination. And also pointing out this was never an issue at least not for this thread.

So this whole thing started when I claimed, much as the gentleman in your video, that colour was an illusion.

Perhaps, whether or not something counts as an illusion depends on whether one is deceived by it. For example, if a shop has a back wall which is a large mirror, and someone who doesn’t know that shop walks in, then they may think the room is twice as large as it really is. For that person, the mirror image is an illusion, they have been deceived about the nature of reality. If another person who knows the shop well walks in, then they also see the same mirror image, but they are not deceived by it, they may use it instead to check out parts of the room which they couldn’t see otherwise, they are using the mirror image as a tool like a car mirror. For the second person, the mirror image is not an illusion, it’s a useful tool for getting correct information about reality. Both of these people are getting the same sense-data from their visual systems, but whether those sense-data are an illusion or not depends on their interpretation. Or perhaps, more accurately, the second person is not dismissing the mirror image as a total illusion, they are correcting the illusory aspects of the image, while keeping the useful information.

I am saying that mirror images give us useful information about the world, but if we think they are direct representations of reality then they can become illusions. In the same sort of way, I think that the mirror systems in our brains which have evolved to give us information about other people’s thinking (by mirroring our own brain processes) are indeed useful, but they can become illusions if some misleading aspects of them are taken to be real.

Two aspects in particular (of the way we think about other people’s and our own thoughts) are misleading in that they are contradicted by the evidence from science: the idea that thoughts are essentially private to each individual, and the idea that we originate our own decisions. It’s these two aspects of qualia which are felt to be weird, anti-science. But I don’t think we need to accept those two aspects of qualia, in the same way that we don’t need to suppose that a room with a mirror for a back wall is twice as large as it really is, even though that is what it looks like.

I think there are good reasons why we have evolved to have those two misleading ideas, and why they can still feel persuasive.

1. The idea that thoughts are essentially private. Until very recently, we had no detailed information about the mechanistic brain processes which underlie our thinking, and even now brain scans are blunt instruments, without the resolution at the level of individual neurones firing many times per second which would be needed for useful prediction. The evolved mirror systems (unlike brain scans) are essentially guesswork, and while very useful, they are extremely vulnerable to our capacity for lying and concealing our thoughts, which we use all the time. It’s good to bear in mind that however convincingly I imagine what someone else is thinking, I could have got it entirely wrong (the basis of most novels). For practical purposes, our thoughts are still private to ourselves, so it is easy to be misled into thinking this is a feature of the ultimate reality of thoughts. If we think qualia are essentially private to each individual, then I would say we are making a mistake in the same way that someone thinking the mirror image is another half of the room is making a mistake. Science hasn’t got to the stage of reading thoughts in detail yet, but there’s nothing in principle to say that it won’t in future. (Of course, it may yet turn out differently, we can never be sure what will happen in an experiment, but the evidence so far suggests that thoughts are not inherently unreadable, they are merely mediated by exceedingly fast and complex processes.)

2. The idea that we originate our own thoughts and decisions. This includes qualia, if we suppose, for example, that one person could have a quale which is the same as most people’s yellow qualia, when they are looking at a red bus, and also that this would not show up as originating in their brain wiring. The scientific view is rather that any differences in qualia must (assuming the scientific model is correct) be caused by differences in the brain mechanisms. The unscientific misleading idea that we originate our own thinking runs into morality and the way human societies organise themselves, so it can feel actively dangerous to question it. Again, I think the correct response is that for practical purposes, because we don’t yet understand brain mechanisms in any detail, normal adults can be taken to originate their own decisions and actions (punishments and rewards are, so far, the best ways to influence them, not brain surgery), but that this is not an indication of ultimate reality.

In summary, I think that for most practical purposes in everyday life, when considering our thoughts and other people’s thoughts (including colour qualia), those mental events can be taken to be private to individuals, and originated by them, but that there is no need to suppose that the privacy or the origination, both of which contradict science, are aspects of ultimate reality. If they are treated instead as useful approximations (like Newtonian mechanics), they can be useful without being misleading illusions.

?

zoon wrote:In summary, I think that for most practical purposes in everyday life, when considering our thoughts and other people’s thoughts (including colour qualia), those mental events can be taken to be private to individuals, and originated by them, but that there is no need to suppose that the privacy or the origination, both of which contradict science, are aspects of ultimate reality. If they are treated instead as useful approximations (like Newtonian mechanics), they can be useful without being misleading illusions.

Wow! Where to begin?!
A. Colour vision is not a thought, even if the qualia that may be associated with it are. It is merely something to think ABOUT. Vision occurs in the visual cortex, not the prefrontal cortex.
B. "...privacy or the origination, both of which contradict science"?? How so? The origination of our own ideas may be mainly through stimulation by sensory input (either before or during the idea). In my experience, at least.
C. "treated as useful approximations" to what, exactly?

... Surely, you can't believe that claiming to have had an idea is solipsist (the notion that nothing exists outside of the mind)??

EDIT: Actually, the whole post by zoon is absurd.

Jesus Christ, David. Read the fucking post.

scott1328 wrote:Jesus Christ, David. Read the fucking post.

Which post would that be, Scott? Perhaps you could provide a link to it, then there would be less ambiguity in your post.

...Perhaps it's zoon's last post, which I read much of, enough to realise that it doesn't make sense.

DavidMcC wrote:

zoon wrote:In summary, I think that for most practical purposes in everyday life, when considering our thoughts and other people’s thoughts (including colour qualia), those mental events can be taken to be private to individuals, and originated by them, but that there is no need to suppose that the privacy or the origination, both of which contradict science, are aspects of ultimate reality. If they are treated instead as useful approximations (like Newtonian mechanics), they can be useful without being misleading illusions.

Wow! Where to begin?!
A. Colour vision is not a thought, even if the qualia that may be associated with it are. It is merely something to think ABOUT. Vision occurs in the visual cortex, not the prefrontal cortex.
B. "...privacy or the origination, both of which contradict science"?? How so? The origination of our own ideas may be mainly through stimulation by sensory input (either before or during the idea). In my experience, at least.
C. "treated as useful approximations" to what, exactly?

A. I don’t think I’ve claimed that colour vision is a thought. In the paragraph of mine which you quote above, I said that colour qualia are thoughts, things that we’ve evolved to categorise as mental events. You appear to be agreeing with that categorisation?

B. Again, as far as I can tell I’m agreeing with you. You are saying that ideas are caused by physical events, which is the usual modern view, based on science, and I agree with it. The older view of dualism, which can still feel persuasive, is that mental events are essentially different from physical ones, and are not part of the physical causal chain. Both of us disagree with dualism (at least, I think you do?). Romansch was asking whether colour is an illusion. I think Romansch was referring to colour qualia, the way colours seem to us, taken as thoughts or mental events. I’m arguing that we’ve evolved to think about other people’s minds (and by extension our own) in a different way from ordinary physical objects, and that we still use this evolved trick for thinking about minds because science hasn’t yet come up with anything better. Without neuroscience, it does appear that mental events and physical events are very different, which was why Descartes (writing before neuroscience got going) proposed dualism. My answer to Romansch’s question is that in my view we still need to use the prescientific evolved distinction between thoughts and things, but we don’t need to suppose that thoughts are as different from physical events as they seem. If we go along with the way that thoughts, or qualia, seem, and suppose that they are essentially non-physical, then qualia are an illusion. If we recognise qualia as useful constructs of our brains, then they are not illusions. We can just discard gods, they are now useless concepts, but we can’t yet discard qualia, because we still need to use the ancient evolved way of thinking about other people until neuroscience catches up.

C. Approximations to dualism, but not actually dualism, as discussed above.

zoon wrote:

DavidMcC wrote:

zoon wrote:In summary, I think that for most practical purposes in everyday life, when considering our thoughts and other people’s thoughts (including colour qualia), those mental events can be taken to be private to individuals, and originated by them, but that there is no need to suppose that the privacy or the origination, both of which contradict science, are aspects of ultimate reality. If they are treated instead as useful approximations (like Newtonian mechanics), they can be useful without being misleading illusions.

Wow! Where to begin?!
A. Colour vision is not a thought, even if the qualia that may be associated with it are. It is merely something to think ABOUT. Vision occurs in the visual cortex, not the prefrontal cortex.
B. "...privacy or the origination, both of which contradict science"?? How so? The origination of our own ideas may be mainly through stimulation by sensory input (either before or during the idea). In my experience, at least.
C. "treated as useful approximations" to what, exactly?

A. I don’t think I’ve claimed that colour vision is a thought. In the paragraph of mine which you quote above, I said that colour qualia are thoughts, things that we’ve evolved to categorise as mental events. You appear to be agreeing with that categorisation?

B. Again, as far as I can tell I’m agreeing with you. You are saying that ideas are caused by physical events, which is the usual modern view, based on science, and I agree with it.
....

The word, "caused" may be misleading, because it could be taken to mean "directly caused". It is scientifically more correct to argue that ideas are the result of observation of physical events.

zoon wrote:
Perhaps, whether or not something counts as an illusion depends on whether one is deceived by it. isleading illusions.

Perhaps ... I am reminded of a magic show I went to at Niagara Falls. A lady disappeared from the cage and a honking big tiger appeared. Was I deceived by it? No. Was it an illusion? Is the man staging the tricks a magician or an illusionist? So ultimately this could be a semantic storm in a tea cup.

Having said that, I have tried to be consistently clear that by illusion I mean not as it seems.

So here I don't mean my qualia of the bus being red, means that the bus is that same red (if it indeed does have a colour). So the bus seems red to me but it may (likely) not actually be the red of my qualia.

This has nothing to do with how good my colour (photons of different wavelengths causing photochemical reactions in my retina) discrimination is or how useful it may be.

Red cannot be an illusion, if an illusion is defined as "not what it seems," and "red" is defined to be a label the mind attaches to a particular class of sensations.

scott1328 wrote:Red cannot be an illusion, if an illusion is defined as "not what it seems," and "red" is defined to be a label the mind attaches to a particular class of sensations.

Semantically I get your point ... but an object having a colour can be not what it seems.

scott1328 wrote:Red cannot be an illusion, if an illusion is defined as "not what it seems," and "red" is defined to be a label the mind attaches to a particular class of sensations.

There's probably a distinction to make between casual definitions and rigorous definitions.

In daily use, "red" is a range of colors or wavelengths. That suffices for most conversations. Red apples, red buses, red motorcycles. All red. All different.

But, we can get a lot more specific if we need to, of course.


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scott1328 wrote:Red cannot be an illusion, if an illusion is defined as "not what it seems," and "red" is defined to be a label the mind attaches to a particular class of sensations.

The point is that labels are not the things they refer to. SoS likes 'don't mistake the finger for the moon' or something like that. "Mistake the map for territory" is another. The map can be as accurate as you like. The label can refer precisely. We are not mislead about the pigment on the bus.

The 'illusion' is not that the label points to the wrong thing (David's "misleading" error) but that the label is a label not a thing in itself.

You know, you've come all the way to a kind of word called an adjective.


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GrahamH wrote:

scott1328 wrote:Red cannot be an illusion, if an illusion is defined as "not what it seems," and "red" is defined to be a label the mind attaches to a particular class of sensations.

The point is that labels are not the things they refer to.

Graham, as you acknowledge consciousness and/or the brain has no absolute/direct knowledge/observation of anything, so please therefore inform us of something which is not an illusion.

Materialists/physicalists are demonstrably guilty of associating the meaning of 'illusion' wrt popular experience/learning which have no actual bearing upon ontology/metaphysics. Guilty of irrational/incorrect conceptualization.

How you bunwits attain the confidence to hang around the philosophy forum as though you own the joint, will always be a puzzle to me.

jamest wrote:

GrahamH wrote:

scott1328 wrote:Red cannot be an illusion, if an illusion is defined as "not what it seems," and "red" is defined to be a label the mind attaches to a particular class of sensations.

The point is that labels are not the things they refer to.

Graham, as you acknowledge consciousness and/or the brain has no absolute/direct knowledge/observation of anything, so please therefore inform us of something which is not an illusion.

Knowledge is by nature indirect. What is 'direct knowledge'? If you know X about Y then X is not directly Y.

The point here is that colour experiences (qualia) are knowledge' of subject relative to object, not some subjective thing in itself that is observed or 'felt' by a subject mind. The function of seeing a red bus is not identical with experience of seeing a red bus. There is 'knowledge' of the bus and 'knowledge' of seeing it. I scare-quote 'knowledge' because I refer to information processed by the brain, not a subjective experience of knowing or thinking about it.

My wife was hanging laundry to dry just now. I watched her hanging a shirt that, by its color alone, I didn't recognize. It wasn't mine, but it is my size. Turns out it is a corporate giveaway from work, that I gave to my oldest son.

Cool thing, though. Neat demonstration that my model of reality (the colors of my shirts) is in color, and it worked to quickly realize that strangely colored shirt to be alien.


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