• Hanover
    12.9k
    The fact that we know that phenomenal states can exist without external stimuli and that phenomenal states can be manipulated to provide varying perceptions of the same external stimuli forecloses direct realism as a viable option. Yet it persists.
  • Lionino
    2.7k
    Oh, no. It is the indirect realism X direct realism discussion all over again. Here we go 50 pages.Lionino – page 7

    I am excitedly looking forward to the moment my prediction realises and my smugness fully blossoms as a beautiful orchid.
  • jkop
    903
    I see colours when I dream and hallucinate.Michael

    No, those are experiences evoked by stimulation of the neural connections that your brain developed when you were awake and did see colours.

    When you dream or hallucinate seeing a colour, you have the experience, but you don't see anything, and that's why they're called dreams and hallucinations.

    Brain stimulation is insufficient for colour-experiences. Stimulation from a sense organ that interacts with light and discriminates between different wavelength components is necessary for colour experiences. Therefore, colours exist outside of the brain. They emerge from the interaction between the whole visual system and available light and pigments
  • Michael
    15.6k
    those are experiences evoked by stimulation of the neural connections that your brain developed when you were awakejkop

    And colours are constituents of these experiences.

    When you dream or hallucinate seeing a colour, you have the experience, but you don't see anything, and that's why they're called dreams and hallucinations.jkop

    This is a word game. You might not like to use the phrase "the schizophrenic hears voices" because it's an hallucination but it is perfectly acceptable to describe the phenomenon in this way.

    Brain stimulation is insufficient for colour-experiences. Stimulation from a sense organ that interacts with light and discriminates between different wavelength components is necessary for colour experiences. Therefore, colours exist outside of the brain.jkop

    That does not follow. Colour experiences might depend on neural connections which only develop in response to optical stimulation by light, but your conclusion that therefore colours are mind-independent properties of light/distal objects is a non sequitur.
  • jkop
    903
    The fact that we know that phenomenal states can exist without external stimuli and that phenomenal states can be manipulated to provide varying perceptions of the same external stimuli forecloses direct realism as a viable option. Yet it persists.Hanover

    Well think about it.

    A blind person doesn't have visual experiences. Without a working light-sensitive organ that stimulates the brain to develop the necessary neural connections for having visual experiences, the blind guy can't have any visual experiences. There's no way a neurologist could artificially evoke visual experiences without the necessary neural connections in place. They're developed naturally when our working light-sensitive organs interact with the behaviour of available light in our environment..

    It is indeed possible to temporarily evoke visual experiences while blindfolded, dreaming, hallucinating etc i.e. when we don't see anything. But then we are exploiting the neural connections that our brains developed when we did see things.
  • Hanover
    12.9k
    I don't see how that suggests that color of the pen is part of the pen and not the person's perception. It just describes how perceptions occur.

    We can also stimulate non-functioning auditory nerves in the profoundlly deaf by implanting a cochlear implant. Once implanted, the person will begin experiencing beeps that he learns to translate into words and sounds so that he can properly respond to them. That person's perception of the sound is entirely different from those with normal functioning auditory nerves. That would lend support to the fact that the sound is not in the bird's chirp, but it's in the listener's head, and there is no reason to believe that the deaf person's perception of the chirp is the same as mine.

    We both would say, however, that the bird chirped, yet our internal states would be entirely different.

    I can imagine the same could be done of vision, where an artificial visual stimulator could offer flashes that could be perceived such that the person would call an object a "chair," but his perception of that chair would bear no resemblance to my own. He'd see a particular array of flashes, yet I'd see a particular shape, yet we both have the shared experience of something, both of which we use the shared word of "chair."

    That explains linguistic use. It doesn't explain metaphysics and it refutes direct realism.
  • Harry Hindu
    5.1k
    I'm not sure what "aboutness" has to do with anything being discussed here. This history textbook is about Hitler, but it isn't Hitler; it's bound pieces of paper with ink writing.Michael
    So you've never heard of Franz Brentano and intentionality of mental states? If you don't want to continue the conversation just say so. It's much more becoming than playing dumb.

    What does that mean for some bound pieces of paper to be about something else? If all humans disappeared but our books were left behind, would the bound pieces of paper still be about Hitler? In other words, is aboutness mind-dependent?

    I would argue that aboutness is everywhere causes leave effects. The book is about Hitler because of the existence of Hitler and someone's intent to write a book about him. The book would not exist if neither of those events happened. The crime scene is about the criminal because of the evidence the criminal left behind. The tree rings are about the age of the tree as a result of how the tree grows throughout the year. The color red is about the wavelength of light entering your eye. Of course I've simplified the causal processes significantly, but my point is that effects carry information about their causes. As such, information is everywhere. The world is not physical or mental. It is informational. Relational.

    May I suggest the following book: https://press.princeton.edu/books/hardcover/9780691144955/aboutness
  • jkop
    903
    I don't see how that suggests that color of the pen is part of the pen and not the person's perception.Hanover

    The blind can't see the red pen, and if brain-stimulation is insufficient for making the blind see it, then I don't know of a good reason to believe that the red pen that we see is a brain event.

    We can also stimulate non-functioning auditory nerves in the profoundlly deaf by implanting a cochlear implant. Once implanted, the person will begin experiencing beeps that he learns to translate into words and sounds so that he can properly respond to them.Hanover

    Yeah, perhaps some functions are easier to replace with prosthetics? Echolocation can to some extent replace some of the functions of vision, but it ain't vision. The human eye is so sensitive that one single photon causes a measurable response in it. The visual system discriminates intensities and wavelength components, and the brain develops and adjusts neural connections accordingly. A comparable prosthetic visual apparatus seems implausible, but who knows?

    Even so, it seems fairly clear that brain-stimulation is insufficient. The blind could learn to use an artificially applied vibration inside the brain for identifying objects and states of affairs, and we could call it "vision". But it's a meaningless or different use of the word vision. Our behaviours would begin to differ, I imagine.

    Regarding direct realism, I won't discuss it here. It has its own long thread.
  • Harry Hindu
    5.1k
    The same way you don't confuse the car on your left from the car on your right: the direction of stimulation is extremely influential on how we perceive the stimulus. Throwing one's voice is a good example of where this is writ large - despite there being no voice coming from the direction one perceives (when on the receiving end!) - that is what one perceives. We can even be tricked about hte direction stimulus is coming from. Not being able to locate an itch is another perfect example. "I can't put my finger on it" has developed out of this experiential norm.

    On-point to your comment, your internal depth perception is what creates the experience of distance - not the distance itself. It is your mind interpreting it which is why perspective can get really fucked up really quickly in the right physical circumstances. The mind does what it thinks it should be doing. It is not veridical in the philosophical sense.

    I should say, if your argument is in line with Banno's hand-waving idea that we can somehow magically see things veridically, despite that being in direct contradiction of hte science of perception, I'm unsure we'll get far - which si fine, just want to avoid you wasting your time here if so.
    AmadeusD

    That's a cool trick the nervous system does. Pain is handled by a special neuron called a nociceptor. People who have chronic pain develop nervous superhighways so that any pain stimulus in the area jumps onto the same path. In other words, they lose the ability to correctly locate the pain. That problem can eventually progress until they have what's call "generalization" where they can't locate pain at all. It's just everywhere.frank

    I don't see how any of this contradicts or contrast with what I have been saying, including the part where I mentioned the distinctions between direct and indirect realism.

    You feel the pain in your mind.AmadeusD
    Which is to say that the mind interprets the pain (information) as located in your toe. Information has to be interpreted. When we get at the actual cause is when we have interpreted something correctly. We still experience mirages even though we know the actual cause of the experience. Understanding the correct cause doesn't dispel the illusion. It becomes predictable. We can now predict when we will experience a mirage based on certain environmental conditions.

    What I find so odd is when someone makes these scientific explanations, like frank did above, as if that somehow makes what we experience questionable, when science is based on empirical observations. Why should I trust frank's explanation to be veridical? Why should I trust your post as possessing any type of veridicality? Either what you and frank said is true, or it isn't. Which is it? You only pull the rug out from under your own statements when you call into question what your statements are based on. It's like the silly saying, "We don't know anything" when that is a statement of knowledge. It sounds like you are the one on Banno's side with your word games.
  • Harry Hindu
    5.1k
    I don't understand the reasoning behind this question. You're asking why speak at all if our speech isn't 100% accurate and complete in terms of what it conveys? My response would be because knowing something is better than knowing nothing. Why did we have black and white photography before color photography came out? Because something is better than nothing. And, I'd say, I don't labor with the belief that current color photography is 100% accurate in what it depicts. It's 2 dimensional, for example.

    As in my example earlier of the air traffic controller looking at blips on his radar screen. No one believes that airplanes are blips, but we can all see the value in having him look at those blips.
    Hanover
    Which accomplishes the task of having planes land and take-off in a safer way. The blips accomplished the task they were designed for - nothing lost in translation.

    In saying that no one believes the airplanes are blips, you are implying that we aren't expecting more than what the blips are telling us to accomplish some goal. We don't need to know the color of the plane to prevent it from crashing into another one while landing.


    Will the real Genesis 1:2 please stand up? That is, the one where nothing gets lost in translation.Hanover
    How about they all stand up together?
  • Michael
    15.6k


    You seem to misunderstand my point. Dreams can be about things but dreams are still mental phenomena, caused by neural activity in the brain.

    So your claim that distal objects are the intentional objects of waking experience and so therefore colours are mind-independent properties of these distal objects is a non sequitur.

    Intentionality simply has no relevance to the dispute between colour eliminativism and colour realism.
  • Hanover
    12.9k
    In saying that no one believes the airplanes are blips, you are implying that we aren't expecting more than what the blips are telling us to accomplish some goal. We don't need to know the color of the plane to prevent it from crashing into another one while landing.Harry Hindu

    If you're conceding our perceptions might just be a pragmatic stimulus to navigate the world, which may or may not bear any resemblance to the object, then we're agreeing. If the pen is not red, but just appears red, then you're not asserting a direct realism.
    How about they all stand up together?Harry Hindu
    With disagreement. Surely you don't think there is one final interpretation of the Bible that irons out out all the inconsistencies. Jesus died to save mankind from the original sin that occurred in the Garden of Eden said no Jew ever.
  • frank
    15.8k
    If you're conceding our perceptions might just be a pragmatic stimulus to navigate the world, which may or may not bear any resemblance to the object, then we're agreeing.Hanover

    If our perceptions may not bear any resemblance to what's out there, then why believe the science that led you to accept indirect realism?
  • Michael
    15.6k
    If our perceptions may not bear any resemblance to what's out there, then why believe the science that led you to accept indirect realism?frank

    This is like asking why we accept the Standard Model if we cannot see electrons with the naked eye.
  • frank
    15.8k
    This is like asking why we accept the Standard Model if we cannot see electrons with the naked eye.Michael

    I don't think so. It's more like asking why you accept science of any kind if you can't rely on your senses to tell you the truth.
  • Hanover
    12.9k
    If our perceptions may not bear any resemblance to what's out there, then why believe the science that led you to accept indirect realism?frank

    Science reliably predicts the behavior of my perceptions. Physics is the study of the way physical objects are observed to act.
  • frank
    15.8k
    Didn't you say that perceptions may or may not bear any resemblance to the object?
  • Michael
    15.6k
    I don't think so. It's more like asking why you accept science of any kind if you can't rely on your senses to tell you the truth.frank

    Do you trust the numbers on a Geiger counter to tell you the amount of radiation in the environment, even though the numbers do not resemble radiation?

    The presumption you have that one can trust one's experiences if and only if one's experience "resemble" their causes is a fallacy.
  • frank
    15.8k
    Do you trust the numbers on a Geiger counter to tell you the level of radiation in the environment, even though the numbers do not resemble radiation?

    The presumption you have that one can trust one's experiences if and only if one's experience "resemble" their causes is a fallacy.
    Michael

    Why would you believe you actually have a geiger counter in your hand if your perceptions may or may not resemble the object?
  • AmadeusD
    2.6k
    When you dream or hallucinate seeing a colour, you have the experience, but you don't see anything, and that's why they're called dreams and hallucinations.jkop

    I want to try to clarify this before responding - your position is that despite hte experiences being (at times, anyway) indistinguishable, they are not both experiences of colour?

    I need this clarified, as currently, what you've asserted is bare nonsense. Your description actually supports the idea that colour does not reside in the object, but that, even so, you require an object to instantiate the colour? Are you saying the brain "records" colour from objects and replays it to itself while dreaming? Because... Ha...ha?
  • Michael
    15.6k
    Why would you believe you actually have a geiger counter in your hand if your perceptions may or may not resemble the object?frank

    I addressed that with the very question I asked you, and which you conspicuously didn't answer. We don't need our experiences to resemble the things we believe in. The direct realist trusts a Geiger counter even though the numbers on the screen do not resemble the radiation they purport to measure.

    And this is especially true of colour. I don't need to believe that the colour red resembles 700nm light to trust that objects that appear red reflect 700nm light. It's certainly not infallible, but it's reasonable enough.
  • AmadeusD
    2.6k
    What creates the depth perception of pain inside your lungs instead of a pain inside your bowels?Lionino

    You quoted from the comment which is, in almost it's entirety, a response to this:

    the direction of stimulation is extremely influential on how we perceive the stimulus. Throwing one's voice is a good example of where this is writ large - despite there being no voice coming from the direction one perceives (when on the receiving end!) - that is what one perceives. We can even be tricked about hte direction stimulus is coming from. Not being able to locate an itch is another perfect example. "I can't put my finger on it" has developed out of this experiential norm.AmadeusD

    You could add phantom limb sensation to this as an exemplar of why it's totally wrong to think the pain is either occurring, or derived from, the cells you are perceiving to be hurt. They are injured. Not painful. Your mind creates the pain to alert you to the injury - and is very, very often inaccurate. Hell, seeing blood can increase the level of pain in an injury.

    so too are there distinguishing properties of red and white images, and also distinguishing properties of the two sets of code that generates those different images.Leontiskos

    Those distinguishing features are not colours and we cannot accurately map them, other than standardized terminology such as ranges of frequency. It says nothing for their quality or how they have the mind (usually) spitting out a certain colour experience. "not knowing" isn't hte same as "knowing it's not".

    Understanding the correct cause doesn't dispel the illusion. It becomes predictable. We can now predict when we will experience a mirage based on certain environmental conditions.

    What I find so odd is when someone makes these scientific explanations, like frank did above, as if that somehow makes what we experience questionable, when science is based on empirical observations.
    Harry Hindu

    I'm finding it hard to tell whether you're partial to an indirect, or a direct conception of perception. But, given my own position i'll respond to what I see:

    The first part: Fully agree. Understanding that C fibres fire, travel to the brain, and hte brain creates an illusion of "pain in the toe" rather than "signals from the toe being translated to pain to ensure I address the injured toe" has nothing to do with whether there is pain "in the toe". There plainly is not.

    However, these are scientific explanations: The way pain works shuts down the option of direct perception of it. Hanover has made a similar point, and also noted that it just goes ignored - hand-waved away instead of confronted.

    The science of perception, optical physiology, psychology and (in this context) the mechanics of pain fly in the face of a 'direct perception' account. It isn't even coherent, which has been shown several times. I personally find it helpful to continue the discussion, because it helps to streamline and economize responses to clearly inapt descriptions of experience. Intuitive, yes, but as helpful as folk psychology in understanding what's 'really' going on.

    BUT, even with ALL of that said, if the point is that perception is necessarily indirect, then science can only get us so far. Observations are all we have - and I think Michael and I hit a bit of a curvy dead end with this issue. But, personally, I'm happy to just say science is the best use of our perception in understanding regularities of nature. Not much more could be said, unless we're just going to take the socially-apt chats about it at face value for practical reasons. In that case "science is objective" makes sense - but is just not true.
  • frank
    15.8k
    I addressed that with the very question I asked you, and which you conspicuously didn't answer.Michael

    1. Some of what you know about the Standard Model is information from your senses.
    2. The rest is apriori knowledge.
    3, You can't arrive at the Standard Model using apriori knowledge alone.

    Conclusion: you have to believe your senses are telling you the truth in order to accept the Standard Model.

    This is what Russell was talking about. It's a conundrum.
  • Michael
    15.6k
    Conclusion: you have to believe your senses are telling you the truth in order to accept the Standard Model.frank

    I don't even know what you mean by "senses telling the truth". Hanover and I are talking about experiences resembling their causes.

    This is what Russell was talking about. It's a conundrum.frank

    Russell said the opposite: if direct realism is true then we must accept physics, but physics tells us that experiences do not resemble their causes, therefore if direct realism is true then indirect realism is true.

    But your claim – that if indirect realism is true then we must reject physics – is a non sequitur.

    Either way, we have to either a) accept indirect realism or b) reject physics.

    Although I don't want get into the entire direct vs indirect realism debate here. I'm just focusing on colour.
  • AmadeusD
    2.6k
    therefore if direct realism is true then indirect realism is trueMichael

    Haha, I'm not quite sure this is the conclusion that is required here - I think he's pointing out that it's likely neither are the whle story. But this was very, very funny.
  • frank
    15.8k
    I don't even know what you mean by "senses telling the truth". Hanover and I are talking about experiences resembling their causes.Michael

    Why do you trust your senses if what they show you may or may not resemble what's in front of you?

    Russell said the opposite: if direct realism is true then we must accept physics, but physics tells us that experiences do not resemble their causes, therefore if direct realism is true then indirect realism is true.Michael

    That is a conundrum, because it can't be both.
  • Michael
    15.6k
    Why do you trust your senses if what they show you may or may not resemble what's in front of you?frank

    Why do you trust a Geiger counter to tell you the local level of radiation?
  • frank
    15.8k
    Why do you trust a Geiger counter to tell you the local level of radiation?Michael

    If I was like Hanover, I wouldn't trust that I have a Geiger counter in my hand. Is there some reason you can't just answer my question? Why do you trust your senses?
  • Michael
    15.6k
    Is there some reason you can't just answer my question? Why do you trust your senses?frank

    I already have. Why won't you answer my question? Why do you trust a Geiger counter to tell you the local level of radiation? It doesn't resemble radiation at all.
  • AmadeusD
    2.6k
    Why do you trust a Geiger counter to tell you the local level of radiation?Michael

    Michael is now being slightly obtuse, but I think it's because he has answered this:

    The experience resembles the cause. The reading of a Geiger counter does not resemble being irradiated.
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