• BC
    13.6k


    How sensory input arrives at the outer doors of the brain, and is then passed inside is one issue. What the brain does with sensory input is something else altogether.

    Personally, I just don't see images on the surface of glass windows. Maybe you see things that way. If you do, and it works for you, fine.

    I don't think there is any one here who supposes that his brain is in direct contact with objects. The brain has no direct contact with any object or the sensing of it (though the sense of smell is pretty close to direct contact). The brain isn't in direct contact with the world outside the skull.

    The brain constructs a complex model of the world that accounts for things like windows, twigs that appear bent in the water but are not, and so on. The process of model building starts in infancy, and progresses throughout life. If the model is wrong, we may get hurt, embarrass ourselves, or damage something. Feedback tells us whether our model of the world is right or wrong.

    The world seems real to me, though what it would actually look like if we were in direct mental contact with the world I do not know. Our senses are limited, and though we have experience to help, some things we can not sense. I can not hear the high pitches of a bat. Bats are silent, as far as I am concerned. Some people say they can hear them.
  • dukkha
    206
    I think that in a TV screen there is a source of light radiation, right there in the screen, but in the case of glass, the source of light is further beyond the glass itself. So these two are quite different with respect to the "illusion of depth".Metaphysician Undercover

    Your brain doesn't actually know how far the light travelled from an object to the retina. The retina is just presented with a 2D image on its surface. For a rod or cone one light wave is much the same as the other i.e. it does the same thing whether the light wave travelled 10 centimetres or 10km. The depth information, the distance the light wave travelled, is not included in the light wave. It doesn't carry that information with it and pass it on to the retina. Retinal cells just fire off in the same way regardless of how far the light travelled. It is the brain which interprets all the different neuronal impulses and builds this experience of depth.

    If your claim is that the entire visual perception is created by the brain, without any influence from things external to the brain, then what's the point in discussing how the brain differentiates between one object and another, in any sense whatsoever?Metaphysician Undercover

    I'm not sure what you mean by "without any influence from things external to the brain"? In building a visual perception the brain uses neuronal impulses coming from the retina - which fire because light in the physical world is hittin it. Likewise for the other senses, for example in building the experience of sound the brain uses neuronal impulses which are fired off from sound waves hitting your eardrum. All our sensory organs do is convert various physical processes into neuronal impulses. The job of the brain is to use all these various impulses to build an internal representation of the external world - a guess or an approximation. The representation doesn't even need to be accurate or match how the external world is like, it only needs to be evolutionarily useful for the survival and propogation of the organisms genes. So take colour for example, physicalists don't generally believe physical things actually 'look' yellow or red in the physical world (and our brain internally generates a representation of how the objects 'look' which for us are colour experiences. Rather, in the physical world there just longer or shorter waves of radiation. Our retinas only respond to a narrow range of all the various lengths of radiation, firing off neuronal impulses only when radiation from that narrow range strikes it. The brains way of making sense of these impulses is to internally generate a perception which has colour in it. Things look red blue yellow etc. This is not because things in the external world actually look red blue etc, it's because internally representing the radiation the retinas fire off in response to *as a colour experience* is evolutionarily successful. It helps the organism move through the external world better or avoid poisonous plants, or spot the black panther in the green grass (these are just my guesses).


    If all the objects are simply created by the brain, then there is no difference between the TV screen and the glass, because they are both simply creations of the brain.

    Yes, in terms of the physical description/explanation of sensory perception, all visual experiences have the same *ontology* - all are generated/created by a physical brain. But we're not talking about the ontology of visual perception itself - we're talking about phenomenology, how things are presented to us. So to couch it in physicalist terms, when we have a visual experience of glass, has the physical brain created a depth experience similar to the way it creates depth in a television screen experience (but better, so much better that most of us are fooled by it), or has the physical brain created a depth experience which is phenomenologically similar to the depth experience it creates with the objects around our bodies, i.e. the depth experience is NOT illusory - when we see glass the brain has presented to us a visual perception as if the glass is not there/invisible (like air) and we are seeing the various objects beyond the glass at differing depths.

    Or put it like this, does it make a difference in terms of the visual phenomenology, when someone is driving a car with a windscreen or without one? Is the experience the same in both cases, as in the depth of our visual field does not terminate at the inner surface of the windscreen when the car has one, and the depth of your visual field - how far you can see ahead is not changed at all from having a windscreen and not having one. So when there's no windscreen we experience the depth of our visual field as extending all the way to the road beyond the car, and further onward. Is the extent of your visual field unaltered by a windscreen being fitted, so that you are still seeing the road and world ahead of the car, much like you were when there was no windscreen?

    My answer is that it is altered by a windscreen being fitted, whereby the depth of your visual field is reduced from extending all the way out into the road and world, to extending only as far as the inner surface of the windscreen. The image on the inner surface (of the road beyond the windscreen) is so high quality that we (not me) mistake the image for not being an image on the glass, rather we think that what we are seeing is much the same as when there is no windscreen, that we are looking out at the road ahead of the car as if the windscreen was not fitted (in terms of depth - obviously we know there's a windscreen there, the illusion is that we are seeing through it much like (the brain presents the air around us as being 'see-through'.

    Nor is there any real difference between any object created by the brain, in the sense that these are all fictions.

    I wouldn't say this. All experiential objects created by a physical are have the same ontology - they are all internally generated representations of the physical world. But this doesn't make our perceptions 'not-real'. Our perceptions exist they're not fictional. Regardless, this is probably just a debate on how we use the word 'fictional'.

    However, the brain might create such a difference, dictate that X is different than Y. But then any difference is just a difference because the brain determines it as a difference.

    Yes, this is the position entailed by the physical account of perception - our perceptions are representations internally generated by a physical brain (I made another thread recently discussing why this physical brain can't be located within the head we perceive). This does not mean that there's no difference between objects in the physical world, we are discussing how our perceptions are presented to us, and not how the physical world is structured, which is a different issue.
  • BC
    13.6k
    It is the brain which interprets all the different neuronal impulses and builds this experience of depth.dukkha

    How would the brain do that if the only neuronal impulses it had EVER received were 2-D? This is like supposing that we have only ONE EAR and the brain presents us with stereo sound that it creates. How would it know what stereo sounded like if it had the input of only 1 single ear?

    So take colour for example, physicalists don't generally believe physical things actually 'look' yellow or red in the physical world (and our brain internally generates a representation of how the objects 'look' which for us are colour experiences.dukkha

    I have here a lump of 24 caret gold, a ruby, a sapphire, and an emerald. the lump is yellow, the ruby is red, the sapphire blue, and the emerald is green. If these 4 objects have no color, how do they reflect light at a particular wave length? If sun light passes through the emerald, how do the molecules composed of 4 or 5 elements absorb and re-emit green light that lands on your retina and triggers neuronal impulses that your brain decides is green IF there is no color there to start with?

    One of the elements you are leaving out of your scheme is "experience". From experience we know that there is something behind the glass (milk, the yard, the road, fish, etc.), whereas there is nothing behind the television set except wires and dust which don't look anything like what is on the screen.

    Also, how does the brain generate color? It's never "seen a color" it just get's impulses. How does it know that a ruby is red and a sapphire is blue?

    (I didn't and won't read your post on the brain not being in its brain pan. In 25 words or less, where is it hanging out?
  • dukkha
    206
    Personally, I just don't see images on the surface of glass windows. Maybe you see things that way. If you do, and it works for you, fine.Bitter Crank

    Because you are falling for the illusion! We know it's an illusion because of things like the bent stick in water illusion, or how warped glass distorts the world, rose tinted glass makes the world red, magnifying glasses make the world bigger, telescopes bring the world closer to us, cracked mirrors splits the world, etc.

    Just wind your car window down halfway and notice that when you look at the bottom half of the side mirror through the window it does not perfectly match and align (in terms of both the angle, and it just generally looks slightly different, it may be a little tinted or warped) with the top half of the side mirror which is seen through the open window. Or just drive along the road looking at/through the windscreen at the road and then stick your head out the window and look at the road. Keep doing this back and forward - they do not look the same! How can this be if it is the very same road which is being perceived as if we are looking *through* the windscreen? I mean what's the theory here if you say it's the same road, that our gaze somehow catches the refraction and tint of the windscreen as it travels through the windscreen and out into the world beyond? It makes no sense. My theory explains/can account for the change in how the road looks through the windscreen compared to how the road looks if a windscreen was not fitted. The theory makes far more sense and can account for illusions like bent sticks in water, or fish not being where they appear when you spear them, or the rocks on the bottom of the lake wobbling around with the water movement, or glasses giving the world more definition - you are merely seeing an image on the surface of the clear thing, and most people errenousoy mistake the image for being the world beyond.

    I mean look at what is entailed by your understanding of glass in terms of mirrors - that you look through your eyes at the mirror which somehow turns your gaze around and shoots it back at you and behind your body so that you are looking straight ahead and yet literally looking at the world behind you directly. This makes no sense. What does make sense is that you see an image in the mirror and you mistake this for being the actual world behind you (eg in the case of a rear view mirror, you're not actually seeing the road behind you as if the mirror turns your gaze around and shoots it back at the road and world behind your car. My theory makes far more sense - you see an image in the mirror, an almost imperceptibly clear/crisp image, so clear that the majority of people can't even tell it's an image, but nonetheless it's an image seen on the surface of the mirror. People mistaking the image for the road behind the car is much like a cat seeing attacking a cat in the TV screen, or a dog watching in a television a ball being thrown off screen and searching for the ball in your house in the direction it was thrown in - they don't recognise that the depth is an illusion, that they are seeing an image and not an actual cat or an actual ball being thrown.

    Again the analogy/metaphor here is that we can imagine a web cam on the other side of glass pointing outwards, and it feeds the light information which it is detecting, back to the glass as if it were a TV screen, and the glass displays what the webcam detects, an image on the other side of the glass than the webcam facing outwards. The image is so ultra crisp and high def (no matter how close you get you can't see the pixels, unlike a TV screen) that the vast majority of people can't even tell that they are being presented with an image. Like a dog moving his head off screen where a ball has been thrown (by people on TV), you are falling for an illusion.

    This is not to say that the illusion is bad or anything, it's highly useful - it gives us a really good representation of what's beyond the pane, and it's probably a good thing we fall for the illusion while driving because it allows us to navigate the world beyond the windscreen (the 'image' is not only high definition but also an incredibly accurate representation of what we would be seeing were the windscreen not fitted, although not 100% accurate - there's minor flaws such as refraction, warping, tinting, etc). But the point is that it is an illusion that we are seeing the actual road and world beyond the windscreen directly - we are actually seeing a representation, an 'image' on the inner surface. I put 'image' in scare quotes because the depth experience is a lot better than say an image in a photograph or TV screen and I suspect the reason is that there is some sort of ultra high definition stereogram type illusion on the clear thing being perceived. I don't want people to think I'm saying glass perceptions have *literally* the exact same phenomenology as when we see TV screens, that is just an analogy.

    I don't think there is any one here who supposes that his brain is in direct contact with objects.Bitter Crank

    Maybe they wouldn't word it like that but a lot of people in everyday life and it appears a lot of people in this thread seem to believe that we look *through* our eyes, as if we are peering through our retinas at the world. I certainly used to think/feel this way. This is the view of 'naive realism', which intuitively feels like it's the case. It really feels like my gaze is looking out from my eyes at a world which is distinct from myself and continues to exist in the very same way as when I am perceiving it and when I am not (i.e. things continue to 'look' red/blue/etc even when I am not perceiving them, or that sounds are out there at locations in the world, the car engine keeps making noise even when I'm in the house).

    The direct realist, at least my understanding of him, does believe that his mind has direct contact with the physical world. When he perceives something he uses his mind (otherwise how would you be perceiving them), and it is physical objects in the external world which are being directly perceived. He uses his mind to directly come in contact with physical objects. He wouldn't hold that the physical world is within his brain, or his brain is literally touching physical objects, or some other absurdity like that - but because he doesn't subscribe to a representationalist account of perception (the things he sees are the actual physical objects) he would hold that the sensory organs and brain allow ones mind (perceptions are in the mind - note I'm not saying that mind is entirely within the physical brain) to access directly the external physical world.

    The brain has no direct contact with any object or the sensing of it (though the sense of smell is pretty close to direct contact). The brain isn't in direct contact with the world outside the skull.

    The brain constructs a complex model of the world that accounts for things like windows, twigs that appear bent in the water but are not, and so on. The process of model building starts in infancy, and progresses throughout life. If the model is wrong, we may get hurt, embarrass ourselves, or damage something. Feedback tells us whether our model of the world is right or wrong.

    The world seems real to me, though what it would actually look like if we were in direct mental contact with the world I do not know. Our senses are limited, and though we have experience to help, some things we can not sense. I can not hear the high pitches of a bat. Bats are silent, as far as I am concerned. Some people say they can hear them.

    Agreed. So because you hold that all you perceptions have the same ontology - i.e. they're all internally constructed representations of the physical world (by a brain), the. there is nothing absurd about my theory. It could very well be that the brain constructs an internal model of glass in much the same way as it constructs models of images on a TV screen - whereby the light is travelling from the same depth (surface of TV) yet the brains model presents the image on the TV as if it has depth. Some things look further away than others, it's not like we're just seeing a 2D piece of paper. The difference though is we recognise that the depth in the television screen is merely a construction by the brain (we don't think there's actual people behind the TV in our living rooms that we're looking at, whereas with glass we (not me) do not recognise that the depth perceived is an illusion constructed by the brain, we think we are seeing the world beyond the glass.

    Seeing as though my theory is not stupid or absurd, rather it's a competing account of glass, we need to decide between the accounts. How do we do that? We ought pick the theory, like the good scientists we are, that has the most explanatory value. Which account of glass can best account for all the perceptual 'quirks' associated with it? The answer is mine. I don't even know what precisely what the competing theory(s) are, someone will have to spell it out to me. I can't really make sense of it, I mean does our gaze somehow travel through glass and pick up the tint or refraction on the way through then force it onto the world beyond? Makes no sense.
  • dukkha
    206
    I have here a lump of 24 caret gold, a ruby, a sapphire, and an emerald. the lump is yellow, the ruby is red, the sapphire blue, and the emerald is green. If these 4 objects have no color, how do they reflect light at a particular wave length? If sun light passes through the emerald, how do the molecules composed of 4 or 5 elements absorb and re-emit green light that lands on your retina and triggers neuronal impulses that your brain decides is green IF there is no color there to start with?Bitter Crank

    What do you mean by "green" here? Do you mean it as in there is particular range of radiation wavelengths in the external world which the brain physical internally represents as the 'quaila' of green colour?

    Or do you mean that there is green colour in the physical world as if the qualia of green, as if how green *looks* to us exists 'out there' in the physical world, which our physical brain internally represents as the visual perception of green?

    I'm not suggesting the physical world is like this, but let's imagine a black and white traffic light in the physical world. Does the brain represent the colourless traffic light internally, presenting to us an internal model of that black and white traffic light which contains the qualia of red, orange, green? So here we would have a colourless physical traffic light in the external world, which emits radiation of different wavelengths. Physical retinas detect this radiation, and 'convert' the light waves into neuronal impulses. The neuronal impulses fire into the brain and the visual cortex generates a visual experience/perception of a traffic light which has the qualia of red, orange, and green. So we have here a colourless physical traffic light emitting physical radiation, and an internally generated representative experience of a coloured traffic light.

    Or, as you appear to be saying, does the traffic light in the external world have a colour, as in it looks green even when nobody is perceiving it, so it would be like the qualia of green is there even when nobody is around? And our brains internally represent the externally existing quale of green, as a visual perception of green qualia?

    I don't know what you're saying. The above seems to directly contradict with what you've said below:

    The brain constructs a complex model of the worldBitter Crank

    The world seems real to me, though what it would actually look like if we were in direct mental contact with the world I do not know.Bitter Crank

    You don't know what the external physical world looks like, and yet it looks green, or red, or yellow?

    It's like what I've said above:

    I would also like to point out, as an aside, that people ought have no problem discussing the phenomenology of their visual experiences without getting caught up and bogged down by physical descriptions of light and of the physical explanation/description of how perception is generated. I think the only reason this has happened is you all subscribe to the physical description of visual perception while at the same time not grasping that it entails representionalism because you want it both ways - a physical account of perception, and the objects around you being the actual physical objects in the external world which you are directly seeing, much like the naive realist.dukkha
  • Harry Hindu
    5.1k
    According to what Bittercrank wrote though, it is not the same "lightwaves/photons" that touch the stick as which touch your eyes. The ones that leave the stick get absorbed into the water. Then the water releases new ones. If this is true, then this supports dukka's claim that what we are seeing is the water, not the stick. But the photons must also get absorbed into the air, and new ones released into your eyes, so really, you don't even see the water, you see the air.Metaphysician Undercover
    If photons are absorbed, then they aren't seen, nor are they re-emitted as a new set of photons. Light sources emit photons, everything else either absorbs, reflects or bends, or has no effect on the path of light (It is transparent).

    Transparency is when photons aren't absorbed but pass through some medium. Reflection is when photons change direction after interacting with another object that is neither transparent, nor absorbing them. If all light is absorbed by a particular object, then you see the color black. If only particular wavelengths are absorbed, then you see particular colors that represent those wavelengths that were reflected, not absorbed.

    We don't see water, nor sticks. We see light and our brains create a model of the world using this information in light and how it is either being absorbed or reflected by opaque objects, or passing through transparent objects.
  • Barry Etheridge
    349


    You started this journey into madness by claiming that we don't see the stick we see the image of a stick on a screen somehow constructed on the surface of the glass. I asked specifically how the image gets and how we see it. You have totally failed to address either question because ultimately you know that there is no mechanism by which the image can be projected on to this screen and that to see the image would require exactly the same process as to see the stick out of water (and, as explained, in the water!) Your account does nothing except add a totally unnecessary intermediary step which by the principles of Ockham's Razor I hereby utterly reject as I suspect you know it is entirely right to do.

    All of which means that my suspicion that you are trolling here has now reached sufficient strength to warrant my total withdrawal from this pointless discourse and advice to others to do likewise. Feed not the troll, dear friends.
  • Metaphysician Undercover
    13.2k
    Your brain doesn't actually know how far the light travelled from an object to the retina. The retina is just presented with a 2D image on its surface. For a rod or cone one light wave is much the same as the other i.e. it does the same thing whether the light wave travelled 10 centimetres or 10km. The depth information, the distance the light wave travelled, is not included in the light wave. It doesn't carry that information with it and pass it on to the retina. Retinal cells just fire off in the same way regardless of how far the light travelled. It is the brain which interprets all the different neuronal impulses and builds this experience of depth.dukkha

    Instead of saying things like the "brain doesn't actually know", let's refer to what the brain does in relation to sensing, as interpretation. Let's say that the brain interprets the data. I really don't know the mechanisms which are in place by which we judge depth, or distance, but we do have a number of senses, and they all work together. I think that in judging distance, hearing gives us much information.

    Here's something you should consider. The ears operate by detecting waves, just like the eyes operate by detecting waves. The ears, especially in some animals like birds, are very good at determining the position of the source of those waves. Do you not think that the eyes as well might have some mechanisms which work toward determining the location of the source of the waves?

    With respect to depth perception though, distance, do you agree that there is often mistake in our interpretations? Something on the horizon might appear to be small and close, when really it is big and far. There are many different factors which influence one's judgement of distance. Principally, I think we position "objects" relative to each other. A stand alone object on the horizon would be difficult to judge, but if there are other objects, and we recognize the type of object, such as trees, cars, buildings, that recognition gives us knowledge of the size, and we can compare the object at question's relative position. Also, if one moves around a bit, parallax is used in the judgement.

    Things look red blue yellow etc. This is not because things in the external world actually look red blue etc, it's because internally representing the radiation the retinas fire off in response to *as a colour experience* is evolutionarily successful.dukkha

    There is a real difficulty in your phasing here. When you say "things look red..", the "look" here refers to the sense perception of seeing. Then you say "this is not because things in the external world actually look red...". But again, you use the word "look", so you are still referring to the perception of seeing. To maintain consistency, we should say that things actually do look red, because this is how we perceive them, and what they look like is a reference to how we perceive them.

    So what you might like to say, is "this does not mean that they actually are red". In this way you can properly express your belief that there is a difference between the way things look, and the way things actually are. However, you may be faced with the question of is there such a thing as the way things actually are. This is a very valid question, because if things look different from various different perspectives, and various different sensing systems, what justifies the assumption that there is one particular way that things actually are?

    Yes, in terms of the physical description/explanation of sensory perception, all visual experiences have the same *ontology* - all are generated/created by a physical brain. But we're not talking about the ontology of visual perception itself - we're talking about phenomenology, how things are presented to us. So to couch it in physicalist terms, when we have a visual experience of glass, has the physical brain created a depth experience similar to the way it creates depth in a television screen experience (but better, so much better that most of us are fooled by it), or has the physical brain created a depth experience which is phenomenologically similar to the depth experience it creates with the objects around our bodies, i.e. the depth experience is NOT illusory - when we see glass the brain has presented to us a visual perception as if the glass is not there/invisible (like air) and we are seeing the various objects beyond the glass at differing depths.dukkha

    I really think you have created a false dilemma here dukkha. We see the TV as an object, and we judge that we are watching the screen of that object. We see the glass as an object, and we judge that we are looking through that object. We see the body of water as an object, and we judge that we are looking at the stick through that object. What is "actually the case" is not an issue, because we are discussing the way we perceive things, interpret things, and this is how we interpret them. If one did not see the TV as an object, or did not see the glass as an object, or did not see the water as an object, then there would be a problem of illusion.

    So when you say "when we see glass the brain has presented to us a visual perception as if the glass is not there/invisible...", you are stating a falsity, which is really contradictory. If we do see the glass, then the brain recognizes that the glass is there, and it is false to say that the brain has presented us with a representation as if the glass were not there. Only if one was looking through glass, and did not see the glass, could you claim that the representation was as if the glass were not there. But then it would be false to say that the person "sees the glass". That person does not see the glass. And that is why it is possible that someone can walk right into a glass door, because they do not see the glass.

    Or put it like this, does it make a difference in terms of the visual phenomenology, when someone is driving a car with a windscreen or without one? Is the experience the same in both cases, as in the depth of our visual field does not terminate at the inner surface of the windscreen when the car has one, and the depth of your visual field - how far you can see ahead is not changed at all from having a windscreen and not having one. So when there's no windscreen we experience the depth of our visual field as extending all the way to the road beyond the car, and further onward. Is the extent of your visual field unaltered by a windscreen being fitted, so that you are still seeing the road and world ahead of the car, much like you were when there was no windscreen?dukkha

    So again this is a false problem. When driving in a car, we see the windshield, and judge that we are seeing through it. Certain things on the windshield, moisture, dirt, chips, blemishes, and cracks, may affect our vision beyond the windshield, and so we naturally try to account for these problems. If the vision through the windshield is too bad, one will choose not to drive. Contrary to your claim, that it is not, how well you see ahead really is affected by the windshield. It's just that the affect is minimal, so that we can cope with it. No one gets into the car thinking that the windshield is not there, because they see it. If it were super clear, and someone didn't see it, that person might touch it to confirm that it is there, in order to rest assured that bugs and things like that would not get into the eyes.

    We don't see water, nor sticks. We see light and our brains create a model of the world using this information in light and how it is either being absorbed, reflected or passing through transparent objects.Harry Hindu

    I think you misuse the word "see". According to common usage, we see objects. We do not see the light which reaches our eyes, that's not a conventional use of the word "see".
  • Harry Hindu
    5.1k
    I think you misuse the word "see". According to common usage, we see objects. We do not see the light which reaches our eyes, that's not a conventional use of the word "see".Metaphysician Undercover
    I'm not. Seeing is when you are using light as a source of information about the world. Hallucinating or dreaming is when you aren't using light as a source of information about the world.

    The common usage that laymen use doesn't take into account what we currently know about our visual systems.

    I would argue that we don't see objects. We see shapes and colors, which are merely representations of objects. You may say that we experience shapes and colors, but the experience would only be a fraction of the process of seeing itself, as seeing involves light, objects, eyes and a brain. Experiencing seems to only involve the brain - of converting nerves signals generated by the optic nerve which itself was stimulated by EM radiation, into colors and shapes in consciousness.
  • Metaphysician Undercover
    13.2k
    It's not. Seeing is when you are using light as a source of information about the world. Hallucinating or dreaming is when you aren't using light as a source of information about the world.Harry Hindu

    Clearly that's false. Hallucinating still makes use of light, it is a misuse perhaps, but we still see depite the fact that we are hallucinating as well. Classing dreaming and hallucinating together as opposed to seeing, is a dreadful classification, totally unacceptable.
  • Barry Etheridge
    349
    If photons are absorbed, then they aren't seen, nor are they re-emitted as a new set of photons.Harry Hindu

    Nope. If you pour water onto a piece of blotting paper it is absorbed and then after a delay to reach saturation point it is re-emitted. The mechanism is not identical but this is exactly what happens in refraction of light. The photon is momentarily absorbed by a molecule and then re-emitted. It may emerge modified in wavelength or frequency but it is still the same photon. The delay this causes affects the speed of passage of a stream of photons from one surface of a medium to the other. It is an utterly different process from reflection which involves elastic collisions.
  • BC
    13.6k
    You don't know what the external physical world looks like...dukkha

    I think you misuse the word "see". According to common usage, we see objects. We do not see the light which reaches our eyes, that's not a conventional use of the word "see".Metaphysician Undercover

    I would argue that we don't see objects. We see shapes and colors, which are merely representations of objects.Harry Hindu

    According to Hank Williams, we do see light:

    Now I'm so happy no sorrow in sight
    Praise the Lord I saw the light

    It is interesting to hear reports about the world from someone who has had damage in the visual cortex. A friend had had a stroke. Most of her visual field was missing, and the way her brain processed signals from the retina was disrupted.

    What she was "seeing" in her hospital room were horizontal lines, and not much else. As far as I could tell, her room had ordinary painted walls; no posters, pictures, shadows... just plain walls and the usual furnishings. The window in her room was not visible to her. Apparently her brain was no longer able to assemble an image that had vertical lines, shapes, color, brightness, and so on. Of course this was very upsetting to her.

    My understanding is that our brains don't receive "pictures", they receive information about vertical, horizontal, diagonal, and circular lines; edges, solid planes, color, movement, and so forth. Some animals receive a good deal less. Frog vision, for instance, is tuned to movement and edge lines--just enough to coordinate a long sticky tongue.

    The brain assembles edges, solids, lines, colors, and so forth. "We" do not "see" this process; "We" receive the finished image--at least until something goes haywire.

    Apparently brains have evolved to do this without much training. Newly hatched chicks "imprint" on the first animal they see which in a natural setting is their mother. Babies start recognizing their parents very soon (of course other senses are involved in this recognition). We don't have to teach babies how to see. (Teaching people "how to see" usually happens years later in art classes, when students are challenged to look at the world as if they had not seen it before.)

    Learning how to photograph is a lesson in seeing, as is a drawing class. The film or digital receptors sometimes capture the world in unfamiliar ways. Many people (me, for instance) find it very difficult to capture an image of any sort with a pencil and paper.
  • Terrapin Station
    13.8k
    So my strategy now is to show that the scientific view of perception entails representationalismdukkha

    Which is a misunderstanding of the debate. No one is saying that perception isn't involved in perception (of course), no one is saying that perception doesn't work by light waves stimulating your eyes, which send information to your brain, no one is saying that perception involves the object or processes that are perceived to literally be in your brain or to touch your eyes/ears/etc. or for the light waves that touched the object to necessarily be the same light waves that are in contact with your eyes, etc.
  • andrewk
    2.1k
    The OP looks to me like a reboot of the old 'indirect realism' argument, but just using different words.

    If you want to think you are seeing the object, then think that. If you want to think you are seeing a representation of the object, then think that instead. The difference between the two is nothing but word choice.
  • Harry Hindu
    5.1k
    Clearly that's false. Hallucinating still makes use of light, it is a misuse perhaps, but we still see depite the fact that we are hallucinating as well. Classing dreaming and hallucinating together as opposed to seeing, is a dreadful classification, totally unacceptable.Metaphysician Undercover
    How do hallucinations make use of light? When you claim to see a giant spider, where is this reflected light coming from that cause the brain to create an image of a giant spider?

    If we don't see light, then explain how we don't see anything (except the color black) when the lights are out?

    We are capable of hallucinating even when there are no lights, just as we can hear voices even when there are no sounds. When we are deprived of any sensory input for a length of time we begin to hallucinate and dreaming is simply hallucinating while sleeping. The images don't come from light. They come from our imagination and memories.
  • Harry Hindu
    5.1k
    Nope. If you pour water onto a piece of blotting paper it is absorbed and then after a delay to reach saturation point it is re-emitted. The mechanism is not identical but this is exactly what happens in refraction of light. The photon is momentarily absorbed by a molecule and then re-emitted. It may emerge modified in wavelength or frequency but it is still the same photon. The delay this causes affects the speed of passage of a stream of photons from one surface of a medium to the other. It is an utterly different process from reflection which involves elastic collisions.Barry Etheridge
    Me thinks you need a refresher course on the behavior of light:
    http://scienceprimer.com/reflection-refraction
  • Terrapin Station
    13.8k
    If you want to think you are seeing the object, then think that. If you want to think you are seeing a representation of the object, then think that instead. The difference between the two is nothing but word choice.andrewk

    The difference between the two is that representationalists think that, in addition to the perceptual processes that naive/direct realists acknowledge (lightwaves stimulate your eyes, your optic nerves send signals to your brain, etc.), there are additional steps that are akin to your brain making a painting in response to the data you receive, and what you're really perceiving is the painting, where you can't know whether the painting is photorealist or something more akin to impressionism, fauvism etc., because you can only ever see the paintings.

    Naive realists, on the other hand, see perception as more akin to photography. They know that what perception is photorealist, because that's what the process is--it's akin to a natural sort of photography.
  • dukkha
    206
    The OP looks to me like a reboot of the old 'indirect realism' argument, but just using different words.

    If you want to think you are seeing the object, then think that. If you want to think you are seeing a representation of the object, then think that instead. The difference between the two is nothing but word choice.
    andrewk

    No, that's not what I'm arguing. Look at the nearest pane of glass. This thread is about whether what's seen 'through' the glass are the very same objects that would be seen if the pane was removed.

    It's about the extent of your field. Does it extend beyond the pane and terminate at the surfaces of the things in the world beyond the glass, in the same way it would if there was no pane of glass. Or, does it terminate on the surface of the glass?

    Imagine a windowless room. Somebody comes along and mounts a high-def TV screen on the wall disguised as a windows (with a frame etc). On the other side of the wall is a little webcam which sends data to the TV of the world outside. The high def TV disguised as a window displays this data as an moving live image of the world outside the windowless wall. Someone enters the windowless room, looks at the image on displayed on the disguised (as a window) TV screen and thinks he's looking out a window at the world beyond the (windowless) room. He fell for the illusion. The depth of his visual field ends at the TV screen, he's not actually looking at the world beyond the windowless room. If someone came along with a chainsaw and cut a square hole in the wall of the windowless room, then you could look through the hole at the world beyond the room. The depth of your visual field would extend out beyond the hole into the world beyond the room and terminate at the surface of the objects you were looking at. When the man looked at the TV screen he could only see as far as the TV screen on the inside of the wall. Now when he looks through the chainsaw cut hole he can see a lot further than before, out at the world beyond the hole - he is actually looking at the world outside the room. Whereas before, although he thought he was looking out at the world beyond the wall when he looked at the crisp moving image on the disguised TV screen - he was falling for an illusion. He could only see as far as the image on the TV screen. He was mistaken in thinking he was looking *through* a window at the world outside the (windowless) room.

    Now, when a glazier comes along and fits a pane of glass (which is a solid object) into the square hole cut into the wall by a chainsaw, what happens? Does the man in the room see the world beyond the pane of glass, in much the same way as when it was just an empty hole in the wall. Is he looking at the very same objects which exist outside the hole in the wall, glass pane or no glass pane fitted? Or, when the window pane is fitted into the chainsaw cut hole, is the pane for the man in the room much like the disguised TV screen which once occupied the same place as the new window? When he looked at the TV, although he thought he was looking *through* a window at the world beyond the (actually windowless) room, he was mistaken, he was falling for an illusion. Is it much the same case when the pane of glass is fitted into the chainsaw cut hole? Whereby he *thinks* he's looking *through* the pane of glass at the world beyond the room, in much the same way and at the very same things that he was looking at when he was just looking through the empty chainsaw cut hole in the side of the wall, but in actuality, much like the TV screen which presented an image of the world outside the wall that he *mis-took* for the actual world beyond the wall (he didn't realize he was looking at an *image* of the world beyond the room) he is again falling for an illusion, mistaking an image on the inner surface of the pane of glass (much like the image on the disguised TV screen) for being the actual world beyond the room.

    Is glass actually 'see-through'? You can see through the chainsaw cut hole in the wall at the world outside, is it the very same things you are looking at when the pane of glass is fitted into the hole? Although a solid object has now plugged the hole in the wall, does the extent or depth of you visual field (the distance between your eye and the the thing it's looking at) go *through* the solid object (glass) and extend out into the world beyond the wall and terminate at the surface of the objects out there (which WAS happening when the hole was just empty, when you were just looking through the empty hole in the wall cut by the chainsaw)?

    Do we see an image on the glass of the world behind it, or does our visual field penetrate through the solid object and we see the actual things existing beyond the pane of glass, the same objects which we would see, and the same extent of our visual field as would be, when there was no pane of glass fitted and we were looking through an empty hole in the side of the wall?

    It LOOKS as if we seeing ***through*** the pane of glass, we THINK we are seeing the world beyond the pane (the same things which would be seen if not pane was fitted), we INTERPRET what we are seeing when we see a window as being the world beyond that window, as if the glass were 'see-through'. BUT, and this is the entire point of this thread; what we are ACTUALLY seeing when we look at glass is an image on the surface of the pane. And this is analogous to seeing an image of the world beyond a wall on a TV screen. That most of us (not me) are falling for this illusion (they are making the wrong interpretation of what they are seeing, they think they are seeing the world beyond), does not mean that it's not an illusion.

    What's the point of this theory? Why reason do I have to be saying this?

    Because, when we look (supposedly) through glass, and if we remove the glass and then look through the hole in the wall, WHAT WE SEE DOES NOT LOOK EXACTLY THE SAME. If we are looking at the very same objects, why do they look different? Again, look 'out' your windscreen at the road/world beyond the car, and then stick your head out the side window and look at the road,and then go back and forwards. Why does the road not look exactly the same? If you removed the windscreen and did the same thing, the road WOULD look exactly the same (because you actually would be looking at the same road). When the windscreen is fitted, and you are SUPPOSEDLY seeing the very same objects you were seeing when there was no windscreen, WHY DO THEY LOOK DIFFERENT?

    When you look at the rocks at the bottom of a lake, why do they wobble and warp around? They are not wobbling or warping, if you drained the lake they'd be still and stable. If it is the very same rocks you are looking at, why does it bend and warp and wobble when they're submerged under the water, and yet appear still and stable when the lake is drained? How do we explain this? We don't want to say that the rock is literally melting and wobbling and warping around, as if water somehow drastically changed the nature of the rock, rather, we want to say that the rock under the water has the same still and stable properties as when it is not underwater. We THEREFORE have to say that although the rock *appears* to be wobbling and dancing around on the bottom of the lake, it is not. It is actually not warping, and it is still at the bottom of the lake. It is an illusion, it just looks that way.

    How does this illusion work? If (a big "if"), it is the very same rock which we are looking at both submerged under the lake and when the lake is drained, if in both cases we are looking at the same thing, why does it wobble and warp in one case, and not in the other? How can we be looking at a solid non dancing around non warping object, and yet it appears that way? What is the mechanism by which an object can appear one way, and yet in reality be a completely different way AND YET IN BOTH CASES YOU ARE SEEING THE VERY SAME OBJECT. You can't have it both ways, you can't be seeing how something merely appears (to be warping, moving, dancing around, a different colour) and yet also be literally seeing the actual rock.

    You have two completely different things, a warping, dancing rock, jiggling around to the sway of the water. And a solid stable rock which when the lake is drained is not. How are you, in both cases seeing the very same object?

    How cab you be seeing a bent stick that's not bent? When you look at the bend/kink (and warp), how are you are actually seeing a straight stick. When you see the kink, you are actually see a straight stick, and yet it's the vary same object you are looking at. It clearly looks kinked, and yet it's actually straight, and when you look at the kink, you're seeing a straight stick. How can this be? How can an object clearly look kinked, warped and disjointed, and then look solid and straight, and in both cases it be the very same object? And for some reason how it appears when not underwater is in actuality how it is. And not the other way round. Why is the stick not in actuality a warping dancing disjointed stick that merely appears straight when not submerged?

    How can you have appearance, and reality, and yet in both cases be seeing reality?

    Things look bigger in a magnifying glass. But they are not actually bigger. How can you be seeing something which clearly looks bigger and yet it's still the same size, and in yet both cases it's the very same object being seen? How can it be bigger, and the same size, at the same time.

    You might say it merely *appears* bigger/closer, and I'd agree. But I'd say you are seeing a mere appearance, an image on the surface of the magnifying glass. Whereas you'd say you're looking *through* the magnifying glass at an object which appears bigger/closer than how it really is and yet this is not really a mere appearance because it's still the same object that you are seeing magnifying glass or not. It appears bigger/closer, when in reality it's not, but yet you're still looking through the magnifying glass at the reality. How can the very same objects be both bigger and closer, and at the same time the same size and further away, and yet it's the same objects being seen, as if you are looking *through* the magnifying glass at the object beyond.

    You want it both ways. You want to say you're seeing how something merely appears, and not how it actually is (eg "the rocks at the bottom of the lake are actually still, they just look like they're dancing around), and yet it's the very same object being perceived. How can a fish be in one place but really be another, AND YET YOU ARE STILL SEEING THE SAME FISH. You could stand on a wharf and point at a fish caught in a little trap below the surface. Then drain the lake, stand in the same place and point at the fish again. You're not pointing at the same spot, your arm is not pointing in the exact same direction. How can this be? How can you pointing directly at a fish underwater, but in reality you're pointing in the wrong direction because it's not in the place you're pointing to, and yet you're still pointing at the same fish. Either the direction/ location you are pointing to is wrong, or it's not. They can't both be right.

    This is utterly confused and to me at least, just saying "refraction" is nowhere near a satisfactory explanation. My theory easily deals with this; when you point at the fish (supposedly) underwater, you are actually pointing at an image of a fish on the surface of the water (and most likely falling for the illusion of thinking you are literally seeing *through* the water at a fish below the surface). A fish can appear in one place and yet be in another, because you are not seeing the very same fish. There's a fish below the surface of the water swimming round, and there's an image seen on the surface of the water of a fish swimming around. It doesn't appear to be an image to most people (as in, they don't realize what they are seeing is an image, they think they are seeing *through* the water at the actual fish below the surface) but it is. People who think they are seeing an actual fish below the surface, as if the water is 'see-through', as if their visual field extends beyond the surface of the water and down into it extending to the fish and the bottom of the lake around the fish, are wrong. They are falling for an illusion. Water is not 'see-through', the extent of your visual field stops at the surface of the water, you are not seeing anything beyond the surface, the surface of the water displays an image of what is behind it.

    How does it do this? In the same way a mirror does. Surely you don't believe a mirror shoots beach your visual field beyond you, as if it's the very same object being seen in the mirror, and when you turn your head around and look. You see an image in the mirror, which really does look like it has depth beyond the surface of the mirror, but it doesn't. The same thing happens with glass, it presents an image which appears to be actual depth beyond the surface of the glass, but it's just an image. That you mistake this image for the world beyond doesn't make it so. Likewise, that you mistake the face in the mirror for literally being your face as if you've ripped your eyes out and turned them around, does not make it so. Mirrors do not rebound your gaze and shoot it off in directions so that you can look at an object without actually facing it. Surely you can't believe this is so, at least on reflection. My theory is that glass without a silver backing (a window) does much the same thing. The mirror displays an image whats in front of it, the window displays an image of what's behind.

    If you find this hard to believe then go look in a mirror and ask yourself if the face you see is the very same face you would see if you ripped your eyes out and turned them around. Does this actually make sense? Like if you can see in a direction that you aren't even facing, why can't you do feel? Why can't you stick your hand into the mirror and feel your own face? Sounds absurd, the mirror is a freaking solid object right? And besides, you can't reach with your hand one way and yet be feeling something in the opposite direction. Right?

    Then why can you do it with vision? Why can you look straight ahead at a solid pane of glass, have your point of focus even further beyond the pain (like a stereogram) and yet be seeing the actual objects behind you? When you look at a mirror, you see a person which appears at a depth beyond the mirror, which is correlated with your bodies distance from the mirror. It looks as far behind as you are in front. My theory is that it's not correct to therefore interpret the body you are seeing in the mirror, as being the same literal thing that you inhabit. That makes no sense, to think that when you look in the mirror at 'your' hand, it is the literal same object as when you look downwards at your hand. This is wrong and if you think this then you are being fooled by an illusion. Because they are not the very same thing, one is your actual hand, the other is an image displayed in the mirror. An analogy would be when you go on Skype and look at yourself in the screen and wave about your hand, the hand that you see on the screen is an image displayed on the surface of the screen, whereas the hand you're waving around is your actual hand. Nobody (intelligent) thinks that the two hands are literally the same object, as if the computer screen shoots backwards the direction of your gaze. Why do they think that way when it comes to mirrors, and if they don't, if they realize that the mirror is merely displaying an image, then why is clear glass any different? A mirror is just clear glass with a reflective backing, all the backing changes is that the source of the light coming from the pane of glass to your eyes, comes from the objects in front of the reflective backing, whereas with glass with no reflective backing (windows) the source of the light is from behind the pane. If you agree that the mirror displays an image, then you must agree that so too does glass without reflective backing, there's literally no difference other than the direction the light came from before it travels from the surface of the glass to your eyes. With a mirror the light comes from the objects in front of it, hits the reflective back which turns the light waves around (so to speak) which then travel to your retina. If in this case you believe that what you are seeing is an image in the mirror (which you should), then you should also believe the same thing of clear glass, there's no fundamental difference between the two. Mirrors display an image of the world in front of them, glass (and all clear things) display an image of the world behind them. Once we realize it's an image then we can easily account for all the illusions associated with glass/clear things. You stick your arm in the water and it appears bent at the incorrect angle, and appears to be wobbling around even though you aren't moving it, and your hand appears visually to be in a slightly different location that the feeling in your hand. How to explain this? Should we screech "REFRACTION" and think anyone who disagrees with us is a retarded moron who needs an understanding of basic physical theory? Or should we recognise that the water is not 'see-through', we are merely seeing an image of a hand on the surface of the water - you're not looking at your actual hand below the water, and it appears to be wobbling around due to the way in which water alters the direction of light. I really shouldn't need to bring in theories of light and refraction and the "physical world" but it appears some people in this thread can't actually look at a pond without bringing in that theoretical backing. So it's going to looking something like:

    Light is emitted from sun. It travels to the pond on earth. It penetrates through the surface of the pond and into the water, because water is physically transparent - lightwaves can travel through it. You've stuck your hand below the surface. The light which is travelling through the water reaches your hand below and is 'turned around' (your hand is not physically transparent (please can we just say it's turned around and not complicate this further with absorption of particular colours, - although this explains why things appear darker in water, or appear pink in lemonade, or the world looks blue when you look through the top tinted part of your car windscreen). The light which is turned around by your hand below the surface, travels back in a different way than it does through air (I believe it travels slower? Either way it doesn't matter). Depending on the surface angle of the water, is the direction the light travels outwards from the surface. That is, if there's a wave going through the water it spreads out or concentrates the direction of the light depending on whether the surface of the water is convex or convex (i.e. what part of the wave is above your hand). The light travels out into the world at those various angles. Your retina detects the light which is concentrated upon it by the lens of your eye (same sort of thing as the wave does with the light waves). The rods and cones in your retina respond to light entering these cells by emitting an 'neuronal pulse'. The neuronal pulse travels through a series of cells in the optic cord, and then through and across (from the eye the pulse came from) the brain into a part of the brain nearer the back called the visual cortex. [SCENE MISSING]*. You then experience the visual perception of seeing an image displayed on the surface of the pond which is an image of the rocks on the bottom, your hand below the surface, and possibly a fish. The image wobbles and moves around depending on the flatness of the surface it's displayed on. The image of your hand is darker than your actual hand, because a lower amount of light is reflected by your actual hand when it's underwater than when it's above. The image if your hand is displayed on the surface of the water, not in a location which is say there's a straight line from your hand under the water to your eye, the image is not displayed on the part of that straight line which the surface of the water touches. The water refracts the light. So we must imagine this line as being kinked at the surface of the water. The image on the surface of your hand shows a hand in a different spot that where your hand below the surface actually is. The image appears to have depth so when you look at the hand in the image, your point of focus is not at the surface but rather is below the surface (much like a stereogram). Nevertheless you don't literally see world behind the paper displaying the stereogram, likewise you don't see what is actually below the surface, it is an illusion. Falling for this illusion is when you mistake the image of the hand, as in you interpret/think that what you are seeing is not an image displayed on the surface (in the same way a stereogram is actually printed on the surface of paper), but is rather your actual hand below. Not falling for it means you are cool like me.

    Ok, in this gigantic post I've tried to be excruciatingly clear, and painfully over-explain everything. If you still don't understand then I literally give up, I don't know how I can make the theory any clearer. If you do understand but don't agree and have an argument why, I'd be interested to hear.

    *nobody in the world knows what happens here and how/why
  • Terrapin Station
    13.8k
    The depth of his visual field ends at the TV screen, he's not actually looking at the world beyond the windowless room.dukkha

    Actually, I'd say that the part I put in italics is wrong unless there's some reason to believe that what we're receiving on the TV screen isn't accurate.

    What you'd be appealing to there is the different ways that the data from the outside world reach our subject's sensory apparatus. But as I explained earlier, maybe in this thread (I don't recall at the moment), what's at issue in philosophy of perception isn't the exact "mechanical" method by which we're receiving data of the external world. What's at issue is whether what we're perceiving is a brain fiction or "painting" rather where we don't know just how fictionalized/abstracted/stylized it is, so that we can't say just how it links up to the external world as it is outside of our perception.
  • Janus
    16.5k


    This is a very silly argument because light passes through glass just as it does through air or water. You say instead that there is an images projected on the surface of the glass. But our eye is not in physical contact with that surface, the light still has to pass through the transparent medium of the air between the glass surface and our eyes. Are you going to say now that the image is projected on the surface of the air? Have you been consuming mind-altering substances lately?
  • dukkha
    206
    Actually, I'd say that the part I put in italics is wrong unless there's some reason to believe that what we're receiving on the TV screen isn't accurate.Terrapin Station

    Either your making an argument about word use (what's seen in the television screen is in sense an image OF the outside world), or you're talking in absurdities. An image displayed on the pixels of a TV screen, does not contain the literal objects on the other side of the wall! A representation/image is not the very same thing as what's being represented.
  • dukkha
    206
    Have you been consuming mind-altering substances lately?John

    Yawn..
  • Janus
    16.5k


    Ahh, you're going on the nod? I'll take that as a "yes", then....
  • Metaphysician Undercover
    13.2k
    How do hallucinations make use of light? When you claim to see a giant spider, where is this reflected light coming from that cause the brain to create an image of a giant spider?Harry Hindu

    If I'm looking at the wall, and hallucinating a giant spider on the wall, I am still seeing the wall, and making use of light to see the wall.

    If we don't see light, then explain how we don't see anything (except the color black) when the lights are out?Harry Hindu

    Black is not a colour, so it is not the case that we see black, we see nothing. But seeing nothing, when there is an absence of light doesn't mean that we see light. What is the case is that we see objects, but we only see them if they are lit up with light. A laser could shine through the air in front of your eyes, and so long as air is perfectly clear, you wouldn't see it. If you look at the source of the laser light, you see it.

    We are capable of hallucinating even when there are no lights, just as we can hear voices even when there are no sounds. When we are deprived of any sensory input for a length of time we begin to hallucinate and dreaming is simply hallucinating while sleeping. The images don't come from light. They come from our imagination and memories.Harry Hindu

    I know, but in these cases we aren't seeing, nor are we hearing. You don't see while you're dreaming, nor are you hearing when you imagine sounds.
  • Terrapin Station
    13.8k
    An image displayed on the pixels of a TV screen, does not contain the literal objects on the other side of the wall!dukkha

    I've brought this point up again and again. Who is saying that perception, window panes, transparent glasses, etc. LITERALLY contain the objects that we're perceiving or that are on "the other side"?
  • andrewk
    2.1k
    What is the 'visual field' to which you refer? I know what those words mean from a practical point of view, but from that viewpoint, other than the effects of refraction, there is no difference between what is seen through glass and what is seen without the glass there. You appear to be trying to make some sort of metaphysical distinction and I can't see that the distinction boils down to anything more than word choice.
  • dukkha
    206
    I know what those words mean from a practical point of view, but from that viewpoint, other than the effects of refraction, there is no difference between what is seen through glass and what is seen without the glass there.andrewk

    There's tonnes more! Think of magnifying glasses, glasses you wear, curved glass, coloured glass, the reflections which are seen in glass, the wobble of rocks below the surface, telescopes, cracked mirrors split the world, warped mirror galleries, infinity mirrors, the list goes on.

    You appear to be trying to make some sort of metaphysical distinction and I can't see that the distinction boils down to anything more than word choice.andrewk

    I don't know how to make it much clearer. Surely you don't think that when you look in a mirror, you are *literally* seeing your own face, as if the mirror magically turns the direction of your gaze back towards you?

    I give up lol.
  • andrewk
    2.1k
    Surely you don't think that when you look in a mirror, you are *literally* seeing your own facedukkha
    Correct! I would not think, or say, such a thing, because the word 'literally' has a metaphysical odour about it and I avoid making (or thinking) metaphysical claims.
  • Jamal
    9.8k
    @dukkha I think you asked the same thoughtless question back on the old PF, and I seem to remember responding to it. I say thoughtless, because I can't imagine how you can be so stuck on this for years unless you have simply stopped thinking.

    Surely you don't think that when you look in a mirror, you are *literally* seeing your own face, as if the mirror magically turns the direction of your gaze back towards you?dukkha

    Although I agree with Andrew that "literally" doesn't really belong here, nonetheless I would affirm, if specifically asked, that I am literally seeing my own face in the mirror. I'm seeing it indirectly, perhaps--but this is the only way I can see it anyway.

    Or even just look through your windscreen, and then stick your head out your window and look at the road directly. They don't look exactly the same, in fact there's quite a few difference go check for yourself. How do you explain this if in both cases you're seeing the same road, if the windscreen is 'see-through'?dukkha

    To see through something is often to see it distorted. What do you think "see-through" means? If you think to be see-through is to be non-distorting, then you just don't know what it means.

    Treating the light reflected off the object geometrically, one can make a cross-section anywhere along the path from object to eye. One can then stipulate that this cross-section is a projection or image. All you're doing is making your cross-section at the pane of glass, imagining it as an image, and then treating this image as the thing that is seen. You could equally take a cross-section in mid-air as the image that is seen, if that's the way you want to use the word "see". But it's arbitrary and says nothing profound. But it's actually much worse than that, because when you say that this imaginary image is what is seen, you are misusing the word "see" and causing yourself untold confusion.
  • dukkha
    206
    dukkha I think you asked the same thoughtless question back on thjamalrob

    Stopped reading lol
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