Philosophy- What Do we See?

@Fil Albuquerque,

Fil Albuquerque wrote:

I know you and I don´t talk much, but how about addressing the "hard stuff" in the name of clarity which is a thing I know you respect and care for...to where I stand you are just walking around the problem, but then maybe I am just seeing poorly...

If you insist on defining the problem in terms that are obscure, maybe not even intelligible, don't expect a clear solution from me. There is nothing for me to address.

To repeat myself: To answer a question like: "is the `blue' joefromchicago sees the same as the `blue' Fil Albuquerque sees?", you have to define the terms "see" and "the same". There seem to be two approaches to this.

My approach is to define the terms of this question as intelligibly and clearly as I can. The best definition I can think of is that "blue" means, "incoming signal from this kind of photoreceptor, but not from those two other kinds of photoreceptors". Having defined my terms in this manner, there now is a clear answer. It is "yes"---because biophysical experiments would show us that the photoreceptors in Joe's eyes work just like the ones in your eyes. Except when one of you two is color-blind, or red-green blind, or something of that nature. In that case, the answer would be "no, Joe and Fil are not seeing the same colors, because their photoreceptors don't work the same way. In either case, a clearly-defined question leads to a clearly-defined answer.

Alternatively, you can approach the question by failing to define your terms, waving your hands and murmuring words like "common sense" instead. In this case, you cannot intelligibly ask if "Joe's blue" and "Fil's blue" is "the same". There is nothing remarkable in your failure to answer this question, since you hadn't intelligibly asked it in the first place.

1 Reply

@Thomas,

Although sometimes my age and arrogant attitude might lead you to think that I have no respect for people who stand for clarity as you and ken do you are utterly wrong...I have the biggest consideration for those who fight the good fight for clarification even when I enthusiastically, say, "step out of the line"...

...and to answer your counterpoint, no, you are wrong..., I actually set my terms straight, once what in fact I have made clear on this subject, was that the problem is Universal concerning how we process information at large, and that of course including visual information... I am certain you well know what I am talking about as you seem to be a well informed person...

(...mind that you ken Joe or Setanta are "prized targets" for eventual mistakes and that is consideration not lack of it...naturally I could n´t resist but jump at the rare occasion ! )

Regards>FILIPE DE ALBUQUERQUE

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@joefromchicago,

joefromchicago wrote:

If everyone was color-blind, then nobody would know what color was produced by what wavelength. At most, they might suspect that different wavelengths affected different photoreceptors, but they would be totally unable to determine what the effect of those wavelengths might be.

Again, this is not true. To take a different example, all humans are sonar-blind. Yet by examining the sonar-organs of bats, we can tell which geometrical forms they can see, which they can't, and what sounds they need to make to see them. Then we can observe how bats hunt, mate, and fight, while listening to their sonar as they do it. By connecting the dots, we can then get an impression what it's like to "see" soundwaves. Contrary to Mr. Nagel's blather to the contrary, telling what it's like to be a bat is a piece of cake. Nagel's fallacy is all wrong. How he ever got to teach a course in anything is totally amazing. But I digress. The point is that we can draw conclusions of that kind very well. This chestnut about color vision is just another special case of it.

1 Reply

@joefromchicago,

joefromchicago wrote:

Thomas wrote:
That depends on what it means for you to "see" a color. If the sentence "I see blue" means, "incoming signal to my visual cortex from my retina's type-blue photoreceptors", then you're wrong: The biophysics of color and its reception by the eye do tell us that my blue is the same as your blue.

You don't know that. Indeed, you can't know that. At most, all that you can say is that you think my blue is the same as your blue.

As I said in my response to Fil Albuquerque, it all depends on your definitions. In the sentence, "Joe and Fils see the same blue", what is your definition of the terms "seeing blue" and "the same"?

1 Reply

@Thomas,

1 - The "same" and "see" mean what they mean...you do not need to point in that direction...

2 - Since you are not willingly acknowledge your mistake I will give you a practical straight forward example...

Grab a piece of paper and two colour pencils of your choice, say blue and red and draw two squares fully painted side by side in that piece, then do the same process in another shed but change red for green and use the same blue...again repeat the process in another set of sheds but this time use a different blue yet close to the original blue but with far less contrast to the neutral colour of your choice say white or black ... inform your target observers that there is a fake similar blue in one of the compared sets and ask them which one is it...

1 Reply

@joefromchicago,

joefromchicago wrote:

If everyone was color-blind, then nobody would know what color was produced by what wavelength. At most, they might suspect that different wavelengths affected different photoreceptors,

Not just "suspect" it, measure it, too! They could precisely measure which wavelength it takes to make the 11-cis retinal molecules isomerize into their all-trans configuration. They could have measured precisely how the photoreaction differs between the photoreceptors. Perhaps the question wouldn't have looked as interesting to color-blind physicists. But, having asked it, they would have figured out the correct answer.

joefromchicago wrote:

but they would be totally unable to determine what the effect of those wavelengths might be.

Effect on what? On the photoreceptors? Color-blind physicists, perhaps even blind physicists, could have determined that. Effect on your visual cortex, your forebrain, the software running on your forebrain that you call "I"? That's a bit tricker, but give it a couple more decades in brain-scanning technology. We'll get there.

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@Fil Albuquerque,

Fil Albuquerque wrote:

1 - The "same" and "see" mean what they mean...you do not need to point in that direction...

Or in other words, you don't have a definition, only an excuse for failing to offer one.

Fil Albuquerque wrote:

2 - Since you are not willingly acknowledge your mistake I will give you a practical straight forward example...

That's not a test of human perception, only a demonstration of ambiguity in language.

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@Thomas,

Colour perceptually even on a lesser level of awareness is dependent on context...this is not a claim is a scientific fact...and you should know it.

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@Thomas,

I often edit and make posterior corrections when I am replying and translating in real time... re-read it please it should be clear enough now...

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@Thomas,

Thomas wrote:

Fil Albuquerque wrote:
1 - The "same" and "see" mean what they mean...you do not need to point in that direction...

Or in other words, you don't have a definition, only an excuse for failing to offer one.

Fil Albuquerque wrote:
2 - Since you are not willingly acknowledge your mistake I will give you a practical straight forward example...

That's not a test of human perception, only a demonstration of ambiguity in language.

Oh but I do, I just don´t see any fruitful thing come out of it, once my definition should not be that far from yours...

I do hope is clear enough to your understanding on what was meant to be tested...now, if you be so kind please address the remark and don´t use my freaky English as a shield to evade the issue...

1 Reply

@Fil Albuquerque,

...In your shoes the best way to oppose my ground would be to use something like "contextual effect interference" being the word interference the key to a successful counterpoint on my remark...although of course then you would have to justify where does that interference starts and ends to distinguish a true colour perceptual context from one subject to interference...

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Neurology and physics permit us to "explain" how the phenomena of color comes about. But Fil's comment on the contextualism of colour may be a little too complex even for neurology. I can't say. But as a painter I am only concerned with the experience of color, not its mechanical foundations. Even the technical principles for creating color is secondary to the actual experience, the aesthetic phenomena is where its value lies.

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@JLNobody,

If I get to find it again I will show you a video on TED concerning perceptual "mistakes" that the mind does when context changes, colour being one of them...is no big novelty really...in fact is not even to hard to explain straight way some of what is involved regarding contrast for instance.
...if you place a colour with others in brighter tones around it your iris will contract thus changing how you perceive the very same colour if you get to choose a dark background instead...but beyond that there is a complete rearrangement process going on regarding on how the brain constructs any perceptual experience from the stimuli it receives...

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@Thomas,

Thomas wrote:

Again, this is not true. To take a different example, all humans are sonar-blind. Yet by examining the sonar-organs of bats, we can tell which geometrical forms they can see, which they can't, and what sounds they need to make to see them. Then we can observe how bats hunt, mate, and fight, while listening to their sonar as they do it. By connecting the dots, we can then get an impression what it's like to "see" soundwaves.

I'm not sure if you're trying to fool me or just fool yourself. We have no clue what it's like to "see" soundwaves. Any observations we might make of how bats "see" soundwaves are just that: observations of some other entity's behavior. But as to what they actually "see?" We have no idea.

Thomas wrote:

Contrary to Mr. Nagel's blather to the contrary, telling what it's like to be a bat is a piece of cake. Nagel's fallacy is all wrong. How he ever got to teach a course in anything is totally amazing. But I digress. The point is that we can draw conclusions of that kind very well. This chestnut about color vision is just another special case of it.

It's easy? Fine. How would you describe "blue" to a person who is blind from birth?

Thomas wrote:

As I said in my response to Fil Albuquerque, it all depends on your definitions. In the sentence, "Joe and Fils see the same blue", what is your definition of the terms "seeing blue" and "the same"?

"The same" means "identical." "Seeing blue" means to have the visual experience of "blue." I'm not sure how to put it in simpler terms, and I'm not sure why you would have trouble with that phrase. But let me posit this: suppose someone who has perfect vision suffers a brain injury, such that her eyes are fine but she can no longer process any visual stimuli. As a result, she is blind, even though light still affects her photoreceptors in the same way as before. In other words, the blue light spectrum hits her eyes such that a specific photoreaction (trans-cis-isomerization) happens in specific molecules (Rhodopsin) in her retina that we associate with "seeing" the color blue. Now, according to you, is she in fact "seeing" blue?

1 Reply

@Thomas,

Thomas wrote:

Not just "suspect" it, measure it, too! They could precisely measure which wavelength it takes to make the 11-cis retinal molecules isomerize into their all-trans configuration. They could have measured precisely how the photoreaction differs between the photoreceptors. Perhaps the question wouldn't have looked as interesting to color-blind physicists. But, having asked it, they would have figured out the correct answer.

Let's try an experiment: I have a series of buttons in front of me attached to a series of colored lights. Every time I press a button, one of the lights flashes. Through observation, you determine that every time I press the first button, the blue light flashes, every time I press the second button, the red light flashes, and every time I press the third button, the yellow light flashes. Now, tell me what light will flash when I press the fourth button.

Thomas wrote:

Effect on what? On the photoreceptors? Color-blind physicists, perhaps even blind physicists, could have determined that.

Determined what? That certain light wavelengths yield the color "blue?" How would these color-blind physicists know what "blue" is?

Thomas wrote:

Effect on your visual cortex, your forebrain, the software running on your forebrain that you call "I"? That's a bit tricker, but give it a couple more decades in brain-scanning technology. We'll get there.

Dream on.

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@joefromchicago,

The bright thing in there is that your are ultimately questioning causation...you seem to be instead speaking on correlation...I was wondering when you would use the "atom bomb"...there you did it !
I am certain that he was expecting that as well...

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@Thomas,

Quote:

It's a poetic word game no doubt, but---no. A surgeon could take a sample of our retina, examine your photoreceptors under an electron microscope, and tell if you are colorblind, for example. It wouldn't matter if the surgeon was himself colorblind or not.

I understand and fully agree with you. But there is another aspect of the problem.

Until all observers, be it thinking glass or humans, have absolutely the same construction (glass, retina and so on) and see things under absolutely the same conditions, up to the energy of a single photon, they see the same color/picture. But "absolutely" is not perfect word even or especially when we talk about real life objects which indeed are quantum systems. There is always slight difference and unsertanity that are ineliminable - so it's still impossible for two observers to see the same. That's why I like this abstract example with colors wich increases the difference between observers and shows the roots of the problem.

1 Reply

@joefromchicago,

joefromchicago wrote:

But as to what they actually "see?" We have no idea.

Only if you are using the royal "we" now.

joefromchicago wrote:

It's easy? Fine. How would you describe "blue" to a person who is blind from birth?[/quote]
I would describe "vision" in terms of analogies with his sense of touch. Then I'd describe "color" in terms of analogies with sound, or perhaps with radio. To be sure, it would take a while, and the person's understanding of colour would remain imperfect. But it wouldn't be a deep mystery to him.

joefromchicago wrote:

Thomas wrote:
As I said in my response to Fil Albuquerque, it all depends on your definitions. In the sentence, "Joe and Fils see the same blue", what is your definition of the terms "seeing blue" and "the same"?

"The same" means "identical." "Seeing blue" means to have the visual experience of "blue."

That's not a definition, that's just looking up undefined words in a thesaurus and replacing them with other undefined words. Let me rephrase the question: By what tests would you decide what the visual experience of blue is, and that "blue perceived by Joe" is identical to "blue perceived by Fil"?

joefromchicago wrote:

I'm not sure how to put it in simpler terms, and I'm not sure why you would have trouble with that phrase. But let me posit this: suppose someone who has perfect vision suffers a brain injury, such that her eyes are fine but she can no longer process any visual stimuli. As a result, she is blind, even though light still affects her photoreceptors in the same way as before. In other words, the blue light spectrum hits her eyes such that a specific photoreaction (trans-cis-isomerization) happens in specific molecules (Rhodopsin) in her retina that we associate with "seeing" the color blue. Now, according to you, is she in fact "seeing" blue?

No, because my definition requires an incoming signal from the photoreceptors for 460-nm lighwaves, through the optical nerve, into the visual cortex. If her visual cortex can't detect or process the signal, she's blind.

1 Reply

@zt09,

No its not just a fancy tech talk problem of "quantum fluctuations"...
...it is scientific neurological knowledge on how the brain works and assembles information...the kind of knowledge that explains why we do have mirages and how we fill in the gaps on what we cannot perceive or on how the whole of the picture affects each of its individual components...be it in terms of form of meaning or simply colour.

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@joefromchicago,

joefromchicago wrote:

Let's try an experiment: I have a series of buttons in front of me attached to a series of colored lights. Every time I press a button, one of the lights flashes. Through observation, you determine that every time I press the first button, the blue light flashes, every time I press the second button, the red light flashes, and every time I press the third button, the yellow light flashes. Now, tell me what light will flash when I press the fourth button.

The near-infrared light, of course. Obviously you've sorted the lightbulbs in order of increasing wavelength, each 100-200 nm longer than the other. Near-infrared, perhaps 800nm, is the next obvious choice.

joefromchicago wrote:

Thomas wrote:
Effect on what? On the photoreceptors? Color-blind physicists, perhaps even blind physicists, could have determined that.

Determined what?

The effect of different light-wavelengths on different photoreceptors---which is what you talked about in the sentence I was responding to.

joefromchicago wrote:

That certain light wavelengths yield the color "blue?" How would these color-blind physicists know what "blue" is?

They have defined blue to mean "whatever wavelength stimulates type-blue photoreceptors like the ones we've just examined under our electron microscope". Additionally, the color-blind physicists could test the soundness of their definition by shining a 460-nm light onto non-colorblind persons and asking them: "What color is this light?"

2 Replies

Philosophy- What Do we See?

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