'See-through' things (glass, water, plastics, etc) are not actually see-through.
Quoting Wayfarer
My way of understanding this illusion is that 'see-through' things (eg, water, glasses, glass, plastic, quartz, etc) are not actually see-through. Rather they display what's behind them on their surfaces, and we make the mistake of thinking we're seeing the actual thing beyond/behind the surface because the display is so seamless.
So if we imagine a bent straw in a glass full of water. The explanation is that the part of the straw which protrudes above the glass we are seeing directly, whereas the lower half of the straw which appearss below the lip of the glass and looks kinked, is not the actual lower half of the straw within the water, but rather is a almost completely seamless image on the outer surface of the glass. Seamless as in, we mistake the image for being the actual world beyond the surface.
A way of understanding this is to imagine a pane of glass as like an ultra high-def television screen, which takes it's feed from a webcam situated on the other side of the glass and pointing outwards. And the image is so good we mistake the glass for being 'see-through' and it's the real objects beyond the glass which we are directly perceiving.
You're probably better off not believing this (or rather, realizing this is true - which I think it is) haha. Every time I drive now I feel like i'm driving blind. Because I'm not actually seeing the road/world beyond the windscreen. Rather, I'm 'using' a display on the inner surface of the windscreen to drive the car and not crash. The car might as well not have a windscreen, just a webcam on the hood and a t.v. screen inside displaying the image, because it's basically the same thing. Clear things display what's behind them on their surfaces, mirrors are the same but they display what's in front.
Some evidence for this is the stick in water illusion, or when you roll your car window down half way you see that eg, the top half of the side mirror which you are directly seeing through the open window, does not seamlessly match/join up with the lower half of the side mirror which you (supposedly) see *through* the window. 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'?
A stock example is a straight stick appearing to be bent when half-immersed in water. So in that state, it appears to be bent, but when you take it out of the water, it isn't bent.
My way of understanding this illusion is that 'see-through' things (eg, water, glasses, glass, plastic, quartz, etc) are not actually see-through. Rather they display what's behind them on their surfaces, and we make the mistake of thinking we're seeing the actual thing beyond/behind the surface because the display is so seamless.
So if we imagine a bent straw in a glass full of water. The explanation is that the part of the straw which protrudes above the glass we are seeing directly, whereas the lower half of the straw which appearss below the lip of the glass and looks kinked, is not the actual lower half of the straw within the water, but rather is a almost completely seamless image on the outer surface of the glass. Seamless as in, we mistake the image for being the actual world beyond the surface.
A way of understanding this is to imagine a pane of glass as like an ultra high-def television screen, which takes it's feed from a webcam situated on the other side of the glass and pointing outwards. And the image is so good we mistake the glass for being 'see-through' and it's the real objects beyond the glass which we are directly perceiving.
You're probably better off not believing this (or rather, realizing this is true - which I think it is) haha. Every time I drive now I feel like i'm driving blind. Because I'm not actually seeing the road/world beyond the windscreen. Rather, I'm 'using' a display on the inner surface of the windscreen to drive the car and not crash. The car might as well not have a windscreen, just a webcam on the hood and a t.v. screen inside displaying the image, because it's basically the same thing. Clear things display what's behind them on their surfaces, mirrors are the same but they display what's in front.
Some evidence for this is the stick in water illusion, or when you roll your car window down half way you see that eg, the top half of the side mirror which you are directly seeing through the open window, does not seamlessly match/join up with the lower half of the side mirror which you (supposedly) see *through* the window. 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'?
Comments (136)
So your theory becomes irrelevant because in this case, empirical evidence trumps a priori speculation.
So, light waves travel through transparent things.
What's this got to do with whether clear things are 'see-through' or not? Spell it out.
Here is an explanation you might find useful and which you might also find (and I found) to be a bit too much information.
What the science blogger says is this: A light wave passing through glass is absorbed and re-emitted as it passes through the substance.
That it passes through on a straight line is the effect of destructive interference on the waves to the left and right of the center point. The center point is preserved by constructive interference.
Some materials (plastic overlays for windows) are designed to scatter the light. Ordinary clear glass does not scatter the waves, so it appears to be clear.
When a wave of light is interrupted by an opaque object -- like your shoe, for instance -- the light is absorbed and NOT re-emitted.
Never mind whether its a particle or a wave. The light from the sun that bounced off the billions of points on the body of the naked woman sitting on (and denting) your car roof encounters silicon atoms in your window which absorb and re-emit the light in a 'forward' direction. What you are seeing is a stream of light from the sun, bouncing off objects, and (some of it) continuing on to be absorbed at last by the cones and rods in your retina, blah blah blah.
Earth to dukkha? Come in dukkha. Dukkha, are you receiving? Dukkha?
No. You need to spell out what a physical description of light and transparency has to do with whether we can see through clear objects or not.
The argument here seems to be, light waves travel through clear objects and are refracted, therefore we directly perceive what's on the other side of glass.
What does a physical description of light have to do with the phenomenology of clear things? Spell it out.
Quoting Bitter Crank
Can you elaborate on this "blah blah blah"?
Quoting darthbarracuda
That's what it means for a physical object to be transparent. But I'm not talking about that, I'm talking about whether we perceive directly what's on the other side of clear things (that is, whether clear things are 'see-through') or not.
So we see a pane of glass. A physicist might come along and say that the pane is physically transparent - light waves can travel through the object. You two seem to be making this giant leap from what the physicist is saying to concluding that we directly visually perceive what is on the other side of glass.
What does transparency and light waves have to do with the phenomenology of clear things? Can you spell it out?
Anyway, light is passing through two different medium, through transparent air, then transparent water, the only difference is the arbitrary distinction between gas and liquid. I suppose you could try to compare looking at something while in a vacuum, but it might not be a comfortable experience.
A good way to test that theory would be to drop some colored liquid in the water. If the straw changes color, too, then you are looking through the liquid. If it is merely projecting onto the surface, the straw ought to be unaffected by the change in water color. Of course, water has a color, but you need enough of it to start affecting the light, so go to a deep swimming pool, stream or clear ocean. The water tends to appear blue, and things at the bottom of deep water turn blue, proving the light is filtered by the water between the object and the surface.
This theory is wrong. But regardless it entails representationalism (i.e. photons travel through eye to retina, rods and cones convert photons to neuronal impulses, neuronal impulses travel through optic cord into the brain, into the visual cortex, visual cortex generates a visual perception), and therefore the argument still stands. We're discussing the phenomenology of clear things in the world around us. Your recourse to "physical objects are transparent" doesn't matter, because per your perceptual theory we don't perceive physical objects anyway.
Yeah, which is called "see-through" or "transparent." Apparently you came to the conclusion that "see-through" or "transparent" implied "literally invisible," but why you would have come to that conclusion is rather the mystery.
Quoting dukkha
But you are seeing the actual thing behind the surface. That's what "display what's behind their surfaces" refers to.
I've run into a number of folks recently (unless it's one guy posting under a bunch of different names) who seem to believe that naive/direct realism is more or less claiming that an object being perceived, if it's not literally in one's mind, somehow, is in direct contact with one's mind and/or sensory apparatuses--as if naive realists were saying that when you observe the moon, the moon is literally touching your eye.
Clearly, it would be incredibly stupid to claim such a thing. And usually, when it would be clearly, incredibly stupid to claim something, you can assume that that's not what the person is actually claiming. And indeed, that's not at all what naive realists are saying. (I'm a naive realist on perception by the way.)
On the other hand, it's clearly, incredibly stupid to believe that naive realists are saying that when they perceive the moon, the moon is literally in contact with their eyes (or minds), as if they would surely wind up with moon dirt in their eyes. So I have to assume that folks like dukkha do not believe that naive realists believe this. That's why I say, "who seem to believe" above. What they actually believe that naive realists are saying I can't quite discern yet.
So then you agree with me that clear things aren't see through?
Quoting Terrapin Station
Suppose not.
Yawn. Looks like once again Terrapin Station, you've made another argument which doesn't make any sense. And your inane condescending strawman above isn't even worth responding to.
Don't bother replying.
You don't agree with you that clear things aren't see-through.
These objects are see-through because light passes through them (they are transparent) and into our eyes. Our brains use the light coming through our eyes to create a model of the world. This model is made up of visual symbols - of colors and shapes. When we say that they are "see-through" we are saying something about the relationship between the object, light, eyes and a brain. If there was just one part missing (no light, or no eyes, or no brains, or no object) then there would be no such thing as "see-through", or the visual experience of seeing through the air or a window. If there was only objects and light, then there would still be transparency, but no eyes-and-brain system to perceive this, or to complete the process, of being "see-through".
It's similar to colors. Objects aren't colorful. Colors are visual symbols that represent some quality or state of the object (like the yellow of a banana indicates it's ripeness and the black indicates it's rottenness). Colors only occur as a result of light, objects, eyes and brains interacting. Take out either of these things and colors don't occur.
So to say that things that we see through aren't actually see-through, is being contradictory.
He hasn't. You have. Please explain the physics by which the image appears on your hypothetical screen. What is its source, how do you see it? Is it actually there or does your brain project it onto this surface? What happens if there are say two sheets of glass between you and the object, or more? What are you seeing then?
Perhaps when you've done making stuff up to cover the cracks you could take a look at this video ...
... and tell us what's wrong with this simple explanation robust enough to have survived unquestioned for over 400 years.
This seems to support dukka's position. In the stick in water example, what we are seeing is the light being emitted from the water, not from the stick itself. We see the water, not the stick, and the water is not properly "see-through".
That seems like simply shifting the ridiculous straw man a bit, though. Rather than the stick literally being in contact with one's eye, one is talking about whether a specific wave/photon was both in contact with the stick and one's eye.
Yeah, I'm talking about that, too, but the process that you're describing is what it is to see the stick in the water.
No one is arguing that the stick literally touches your eye or that the same lightwaves/photons that touched the stick also touch your eyes. (Even though the latter isn't precluded.) That's not what anyone is saying by "seeing the stick in the water."
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.
Right, and according to my post that you're responding to, "No one is arguing that the stick literally touches your eye or that the same lightwaves/photons that touched the stick also touch your eyes."
No one means that by "seeing the stick."
So arguing against that isn't arguing against seeing the stick. It's arguing against a straw man.
I'm pretty ignorant when it comes to physics. My guess is that photons passing through the air encounter far fewer atoms than they do in water or glass.
When you look at a stick in the water, you are seeing the stick, the water, and anything else that is dense enough, reflective enough, and non-transparent enough to change the light that reaches your retina. I can't see the air in this room because there are not enough atoms to refract light enough to see refraction. When I look out the window, the sky is blue because between me and the upper atmosphere there IS enough gas to refract light waves.
Even in a sealed vacuum chamber virtual particles will appear out of nowhere and the human eye is sensitive enough to detect a single photon. Meaning that, metaphorically speaking, things are transparent to ensure that nobody is ever left completely in the dark.
No. No. No. That's ignoring the wave/particle duality of photons to say nothing of the constant speed of light. When one hits a molecule it is absorbed and re-emitted. What goes in comes out the other side intact. So the photons that leave the stick are the exact same ones that hit our retinas and we do see the stick. Not the water, not the air, not some hypothetical or virtual screen, the stick!
So, refracted light waves reach your retina. The retinal rods and cones convert the refracted light wave into a neuronal impulses. The impulses travel down the optic nerve, through the brain and into the visual cortex. The visual cortex generates a visual experience. This is a type of representationalism. *
It appears nobody can discuss phenomenology without bickering over physical descriptions of light and visual perception. So my strategy now is to show that the scientific view of perception entails representationalism, and therefore we can get back to discussing the OP because it isn't physical things that the representationalism is seeing around him. The world around him is a conscious experience generated by a physical brain, which represents the physical world (which contains refracted light waves) existing beyond the physical brain.
*http://m.pnas.org/content/98/22/12340.full
To spell it out; seeing as though the objects around us are not the physical objects that (we hypothesise to) exist in the external physical world, but rather are our physical brains *interpretation* of the physical world - an internal model, an internal visual representation of the physical world existing beyond it. Because it's not the actual physical object beyond the brain which we are directly looking at (as if our eyes are windows upon the world which we look 'through', but rather an internal visual perception - a representation of those (hypothesised) physical objects, then within the context of this thread we OUGHT have no problems with discussing the phenomenology of the physical brains internally generated visual perception. And the thing we are therefore discussing is whether the brain interprets glass much like it interprets the light coming from a television screen, whereby you are looking at a flat screen, but you also experience an illusion of depth beyond the screen. So to spell it out, if this is the same as how we see glass, when we look at glass we are looking at a flat surface but are experiencing an illusion of depth beyond the glass. Or when we look at glass are the things we see not an illusion od depth, but actual depth as in it is the objects beyond the pane of glass which are being internally represented by the brain.
We can put it like this, does the brain interpret light coming from a pane of glass as coming from a flat surface, much like a television screen (i.e. the brain does not present the TV as if the things on the screen are actually behind the television and we are looking *through* the screen at those objects as if the television is a 3d diorama). Or does the brain interpret light coming from glass in much the same way as it does interpret light coming from objects like chairs cups etc, whereby the depth you perceive is not an illusion on a flat surface.
Is the depth perception we perceive in a pane of glass an illusion on the surface of the glass which makes it look like we are seeing the objects/world beyond the pane of glass, or does the brain interpret light coming from a pane of glass as if the glass is invisible and the light is coming from the various objects beyond the pane which exist at varying depths?
I say that when we look at glass it is much like looking at an ultra high def television screen (no matter how close you go you can't see the pixels!) whereby we are looking at the surface of a flat object (pane of glass) but are experiencing an illusion of depth much like when we see the flat screen of a television but the image displayed appears to have some depth (i.e. some objects appear closer than others, it's not experienced as a 2D flat image it appears to have depth). Of course there is a difference between seeing an illusion of depth in a television screen and seeing one on a pane of glass, and that's that people don't 'believe' the TV screen illusion of depth - people don't think they're actually looking at things which exist behind the television screen - they recognise that it's an illusion and they're just seeing an illusion of depth on a flat screen, whereas MOST people (not me) do not recognise the illusion of depth on the surface of glass (because it's almost entirely seamless) and actually think that, much like someone seeing somebody on a TV screen and thinking that person is behind the television in their house, the depth perceived in glass is not an illusion and it is the objects beyond the pane that one is perceiving.
Basically you're all falling for an illusion and I'm not ;)
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.
Phenomenology has no ontological commitments, so there really should be no issue discussing it without bringing in the theory of physicalism.
This is highly confused. Light from a physical object hits your retina, gets converted to a neuronal impulse which travels to the visual cortex... and then we see the physical stick in the external world directly. How? Light hits the retina and a neuronal impulse travels through the brain, some magic happens and then we look *through* our retinas like they're windows upon the world? This is utterly confused.
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".
Quoting dukkha
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? 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. Nor is there any real difference between any object created by the brain, in the sense that these are all fictions. 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.
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.
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.
Quoting 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).
[quote=]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. [/quote]
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'.
[quote=]Nor is there any real difference between any object created by the brain, in the sense that these are all fictions. [/quote]
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'.
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.
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?
Quoting 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?
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.
Quoting 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.
[quote=]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.[/quote]
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.
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:
Quoting Bitter Crank
Quoting 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:
Quoting dukkha
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.
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.
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.
Quoting 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?
Quoting 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.
Quoting 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.
Quoting 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".
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.
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.
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.
Quoting Metaphysician Undercover
Quoting 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.
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.
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.
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.
Me thinks you need a refresher course on the behavior of light:
http://scienceprimer.com/reflection-refraction
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.
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
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.
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?
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.
Yawn..
Ahh, you're going on the nod? I'll take that as a "yes", then....
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.
Quoting 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.
Quoting 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.
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"?
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.
Quoting 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.
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.
Quoting 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.
Quoting 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.
Stopped reading lol
Your response is just plain ignorance.
You can prove that with a Mach-Zehnder interferometer.
Would you say ulexite is 'see-through'?
Are you looking 'through' the rock at the page behind? Or at an image on the surface?
Are you looking through the ulexite at the paper behind, or at an image on the surface?
Are you looking through the ulexite at the pencil behind, or at an image on the surface of the rock?
Notice how the lines don't match up perfectly. Same sort of thing is taking place when you wind down your drivers side window half way, and notice that your wing mirror seen through the open window doesn't perfectly line up the lower half of the wing mirror seen 'through' the window.
'See-through'? Or an image on the surface?
As the image on the surface becomes clearer, the illusion that the rock is 'see-through' improves. Glass displays a very clear image, and so the resulting illusion is quite compelling. Nearly everyone falls for it.
A magnified image displayed on the surface. You don't look 'through' a magnifying glass.
Large image displayed on surface of rock pool. You are not seeing 'into' the water.
Only the head of the koi out of water is being seen. The rest of the koi is an image on the surface of the pond.
One of the finest examples of this sort of illusion. Images of the world beyond on the surface of the windows, and the actual world beyond seen through the middle.
Mirrors function using the same sort of illusion, but instead display an image on their surface of the world in front of them rather than the world beyond. The idea that when you look at a mirror it's like a portal for your gaze and shoots it back at the world behind you is clearly absurd.
Another example of the mirror illusion, what you are seeing is an image of the world/above in front (rather than below the surface) displayed on the surface of the puddle. Note how the ripples on the surface distort the image.
Refracted half of man is an image displayed on the surface of the glass.
The classic. Only the top part of the pencil above the lip of the glass is what's being seen. Everything below is an image displayed on the outer surface of the cup.
Still think the glass is 'see-through'? If you're looking through the glass at the spoon within, why is the spoon separated and facing the wrong way?
Our eye is not in 'physical contact' with ulexite either, and yet there's an image displayed on the surface. In the youtube video above, the light travels from the card, through the ulexite, and then from the surface of the ulexite/TV rock through the air and is directed onto your retina by the lens of your eye. Some unexplained thing happens here and then we perceive the image of the playing card/toucan on the surface of the ulexite out in the world.
So, if it happens in the case of ulexite, why is it so "silly" to suggest the same process happens in the case of glass?
I highly suspect that the people in this thread who are acting incredulous are just so utterly fooled by the illusion - having misinterpreted their perception of clear objects their entire lives - that the mere suggestion that one of their fundamental beliefs about the world (a lot of things are clear) may be wrong is too difficult to comprehend. They are stuck in their dogmatic ways, unwilling (or even worse, unable) to consider any other interpretation but their own, and lash out at anyone who suggests an alternative. A sort of defensive attack.
The crazy things is that everyone acting like I'm some sort of idiotic moron are in fact the ones not interpreting clear things incorrectly. *They're* the ones being fooled by the illusion and quite frankly the people taking this attitude towards this idea are just embarrassing themselves, at least in my eyes. It's kind of like a young earth creationist calling someone who believes in evolution a silly idiot because creationism is just SO obviously correct, I mean like how could you even be so dumb to consider an alternative?
I've yet to see anyone actually present a cohesive alternative to this theory. Spouting derision is not actually an argument!
Can anyone who doesn't believe in this theory please articulate their understanding of clear things?
Can this image *really* be explained by just saying "it's refraction"? For me, that's not a good enough explanation.
John was apparently pointing out the straw man that you're attacking. You keep ignoring that you are attacking a straw man. Probably because it's not as fun that way.
Right. And how are you defining "see-through" (also versus how you think that other people are defining "see-through")?
That it is the very same object which is being seen, window or not. It's the same road being seen whether a windscreen is fitted in ones car or not.
So if we take how the direct realist sees the wrold, which is that what he sees is how the world exists, and it IS the external world which is being seen (rather than say a representation). The direct realist sits in a car with no windscreen fitted and looks out at the road ahead in the external world. Someone then fits a windscreen. The direct realist thinks that it's the very same road in the external world which he is looking at through the windscreen. In both cases, (he believes) the same object is being seen.
That is what we mean by 'see-through'. It means we can see the same object which is behind whatever transparent thing is in the way (eg windscreen) which we would be seeing if the transparent thing were not there. The transparent object does not block how far we can see ahead, in the same way that a wall does.
This is what we mean by 'see-through'. Whatever is behind the transparent object is what's being seen. The same thing which we would be seeing were the transparent object not there.
But for one, now you ARE talking about perception instead--you're talking about "what we're seeing" per se.
What I was asking for, rather, is basically a definition of what "see-through" means. Something "see-through" would be "see-through" even if you're not seeing an object through it, no? That is, imagine that we put a see-through object in a vacuum. Have the properties of the see-through object changed?
That's what I gave: "This is what we mean by 'see-through'. Whatever is behind the transparent object is what's being seen. The same thing which we would be seeing were the transparent object not there."
[quote=] Something "see-through" would be "see-through" even if you're not seeing an object through it, no? That is, imagine that we put a see-through object in a vacuum. Have the properties of the see-through object changed?[/quote]
I don't know what you're getting at. We would say the object has the property of transparency. If you're a physicalist (who doesn't understand the illusion) you would say that transparent objects are 'see-through'. And that transparent objects continue to have the property of transparency when nobody is looking 'through' them.
"Transparency" is a physical description of an object. It describes the property the object has, of allowing light to travel through the object.
"See-through" is an intuitive description of the way we perceive transparent objects. We think that when we look at transparent objects, we can see the objects which are behind the transparent object. We (not me) think of physically transparent objects as being 'see-through'. Intuitively it seems as though that is the case, that we are seeing through the object. But we are not.
My argument is that our intuition that we can see the objects behind a physically transparent object is wrong.
You got to part of what I was trying to ferret out there inadvertently: you're not using "see-through" and "transparent" as synonyms. I'd say that most people use them as synonyms. I do, too. With the way you're using "see-through," though, you're necessarily going to be talking about perception, because in your view, "'See-through' is an intuitive description of the way we perceive transparent objects."
Re what I was getting at about straw men, what is the difference, in your view, between "allowing light to travel through the object" and "having a property that enables seeing the object behind the transparent object"? Or in other words, how do you believe that most folks believe that "having a property that enables seeing the object behind the transparent object" works? Do you believe that they believe something other than "the property is simply allowing light to travel through the object"?
It doesn't really matter though. Whether glass is see-through or not is not dependent on the amount of people who treat "transparency" as a synonym of "see-through".
You seem to think that "allowing light to travel through the object" is synonymous with "being able to see the objects behind the physically transparent object".
[quote=]Or in other words, how do you believe that most folks believe that "having a property that enables seeing the object behind the transparent object" works? Do you believe that they believe something other than "the property is simply allowing light to travel through the object"?[/quote]
I'm not even sure most people have a theory about how it is that objects are "see-through". I'm pretty sure they just see glass, and believe they're seeing the objects behind the glass. I suppose if pressed a lot would say something about physical light.
"Allowing light to pass through the object" is a physical description of an objects property (transparency).
"Being able to see the objects behind the physically transparent object" is a description of ones visual experience.
They're two different *kinds* of description, which belong in two separate domains (physics, and phenomenology). You appear to be conflating the two and muddling then up. It doesn't matter that the majority of people also do this as well. Whether you can see the objects behind glass or not, is not determined by how many people think they can.
I don't know what you mean by "an image projected on the surface". My understanding is that, according to the physical understanding of seeing ( which is basically all we have to work with) there is no image projected anywhere, but rather light reflected off objects passes through the medium of air, any other transparent medium, or even a vacuum, and then passes through the transparent surface of the eye to fall upon the retina; where it stimulates rods and cones, and electro-chemical nerve impulses are then produced which travel via the optic nerve to stimulate the visual cortex, which produces the experience of seeing anything.
Would you agree that this would entail indirect realism/representationalism? As in, the visual cortex internally generates a visual field experience, with this visual field being within the brain, and therefore what we see is not the physical world directly, but rather an internal representation/model of the physical world. The brain takes in data from the physical world through the various sense organs (whose job is to convert physical phenomena - light waves, sound waves, etc, into neuronal impulses), collates and processes this data into an internal experiential model (with the model being all we directly have access to) of the world beyond it. Do you agree with this?
If so, then we can discuss 'images displayed on the surfaces of clear objects' because it is not actually the physical objects which we see around us. What we see are internally produced (by a physical brain) experiential representations (note the representations don't have to be accurate, as if our visual field is just a smaller scale version of how the physical world exists - all the representations need be is evolutionarily successful, point being that because we see an image displayed on the surface of glass does not actually mean there's an image on the physical glass in the external physical world). Because we are not actually directly in contact with the physical world, what's seen are internally generated representations/a model/internal approximation. So we can discuss images on the surfaces of clear things without debating how this is *physically possible*, without arguing over the mechanism by which the image is displayed, because what we are seeing is NOT a physical object. It's internal, experiential, and produced by a physical brain.
Do you see the point? This physical theory of perception entails indirect realism/representationalism. What we see is not actually the physical world, and how the physical world exists. The brain can internally model images on the surfaces of clear objects. The image we see on clear objects, is not an actual image on a physical object in the external world - it's an internally produced experience. Really, it can internally model the world however it wants. You could say the same thing about colours - the physical understanding is that there is no colours in the physical world, things don't actually look green or red or etc. Colour is an internal experience produced by the brain as a way of representing different wavelengths of radiation in the physical world. In the physical world, all light is is wavelengths of radiation. Our retinas respond to only a small range of the lengths of radiation, firing neuronal impulses only in response to radiation in that range. It internally produces using the data collated from all these various neuronal impulses firing off an experience of colour - the quales of red, blue, green, etc. So the point is that the brain can internally produce an experience of an image on the surface of glass, even though there may not be one in the physical world, in much the same way as it can internally produce colour experiences, even though things don't look red,blue,yellow in the physical world.
We can ask the question like this - how does the physical brain internally represent/model physically transparent objects which exist outside itself in the external physical world? To take a pane of glass for example, I say that the physical brain internal models glass to itself as if the depth of ones visual field does not extend beyond the surface of the pane. So what I mean is that if you remove the pane, the depth of your visual field, phenomenologically, extends out all the way into the surface of whatever objects are behind the pane of glass. Note here that we are not discussing the depth of the physical world or anything like that - because our entire visual field is an internal representation. When we remove the pane, the depth of our visual field - how far it is from our faces to the things (which aren't the physical things, they are internal representations of those things) that we are seeing extends/gets bigger/longer. The distance between our eye and the object it terminates at/extends to, goes from extending merely to the surface of the pane of glass, to the objects which are behind the surface, when the pane of glass is removed. When the pane of glass is refitted, the depth of our visual field becomes shorter, going from extending from all the way out onto the surface of the objects which are beyond the windowless window frame, to being reduced backwards and now only extending as far as the inner surface (the surface of the window facing your eyes) of the window pane.
Tell me if I'm not being clear btw.
So the illusion - the misinterpretation that people make when it comes to clear objects, is that they errenousoy believe the depth of their visual field extends further than it actually does. They think that their visual field extends all the way beyond the window pane and ends at the surface of the objects behind the pane, when in reality they are only seeing as far as the window pane. The reason they are making this interpretation, is because the image which is displayed in glass is extremely high definition and realistic, to the point that the vast majority of people (I've literally never heard of anyone else understanding glass like I do) mistake the objects in the image for actually being the objects behind the pane of glass. They think the depth/extent of their visual field is longer than it is.
If the question is then asked, "but how on earth does glass display an image? There's no pixels in glass like a TV screen, how does it do it? What's the mechanism?" the answer is that we are not actually the physical pane of glass in the external physical world. The pane of glass which we see does not contain within it any mechanism for producing the image displayed on its surface, because the pane of glass is already being produced by a mechanism (that is, physical neuronal processes through some mechanism produce internal visual experiences). The same mechanism which produces the window frame is the same that produces the image displayed on the surface of the window pane. Physical neuronal processes produce the experience of the window pane, and likewise produce the experience of the image on the surface of the glass. Nothing in the glass produces the image on its surface, because the window is itself an internal experience produced by a physical brain.
Do you get it?
I also want to say that I'm not actually a physicalist, I don't believe there is an actual physical world, I'm just explaining my theory here in this thread framing it under a physical theory of perception, because it seems people will be able to grasp it better that way. If you just say that a physical theory of perception does NOT entail representationalism, as in "light from physical objects travel to the retina which sends off neuronal impulses to the visual cortex AND THEN you are back out of your brain having direct access to the physical world", it would still not have any bearing on my theory because I'm not discussing the epistemology of our entire visual fields. As in, I'm not arguing about what we have access to ontologically with our vision (eg the physical world, internal representations, idealism). I'm discussing whether the things which are seen 'through' glass is actually an image on the surface, or are the objects beyond. Not whether the objects are physical or not.
I could make this same post but argue in terms of direct realism, so the direct realists find it easier to understand what I'm saying. But I shouldn't have to do either because this entire theory is about the experiential depth of our visual field (how far away the objects in glass are to us - are they on the surface, are do they appear to us to be beyond the pane). For the direct realist the image they are seeing would be on the surface of the glass in the external world (if the question is then asked "BUT HOW IS THAT POSSIBLE?" then I suggest the direct realist buys a piece of ulexite and sees for himself that images appearing on the surface of physically transparent objects (ulexite allows light waves to travel through it)) IS POSSIBLE AND DOES HAPPEN ALREADY. If they demand an explanation for how images appear on glass and water, then I demand if them an explanation for how images appear on ulexite. Nobody really knows how but the point is that it does happen and is possible.
For the direct realist the question is whether there's an image on the surface of glass in the physical world, or whether your gaze can penetrate through physically transparent objects and see what's behind directly.
For the indirect realist it's whether the brain internally models physically transparent objects as having images on their surfaces, or whether it internally models in its visual field the objects behind the clear thing so that clear things are internally modelled as "see-through". As in when the brain internally models depth, does the depth end at the surface of the glass or does it extend beyond the glass to objects behind it.
For the idealist it's much like the indirect realist but just drop the reference to the brain producing the visual experience. Does the depth of our visual field extend to the surface of glass/clear things, or do we see further, through clear things to the world behind/beyond.
Watch that video on ulexite, that's probably the best way to grasp my theory. Ulexite does present an image on its surface, it has fiber object properties, the light from behind can travel through it. The theory is that it's the same kind of thing happening with glass and other clear things, except the image is far clearer/high def, so clear in fact that the overwhelming majority of everyone ever does not recognise that it is an fact an image, they think what they are seeing is actually the things behind/beyond the surface.
But It can't be the things beyond, due to all the perceptual 'quirks' associated with clear things, which I have outlined all the images I linked above. We can't be seeing the actual spoon within a cup, for example, when the spoon we see is facing the wrong way is completely separated in two. It's an image if a spoon on the surface, the actual spoon is within the cup, and is not facing the wrong way and disjointed.
Agree now?
You write too much here to respond to in any detail. I would find it much easier if you would just focus on a couple of points, and succinctly state your arguments about those.
So, I'll just address a couple of your points. You ask whether I think the physical theory of perception I outlined entails indirect or representational realism. I don't see how it could. If we take the theory seriously then we are assuming that what we have observed and described are phenomena as they actually are. If what we have observed and described is not phenomena as they actually are then no cogent theory at all can be based on it. So, if we reject direct realism then we reject the possibility of any justifiable theory at all. We are just left with skepticism then.
Quoting dukkha
If there is no coherent physical account of how images could be "on the surfaces of things" then I can see no sense in asserting it or even arguing against it. I don't know what you mean by saying that the things we see are not physical objects. They are physical objects by definition. You seem to be suggesting that we see brain images instead, but that notion is unintelligible, because if there are no physical objects then there is no physical brain either. Actually I would say there are no brain images, there are brain processes which are thought to accompany mental images, and I would say that mental images are not are not seen, they just are the seeing. This notion of separation in perception comes about by rationally hypostatizing how we talk about it, We will never be able to comprehensively get our heads around this in a way that will once and for all satisfy our analytic demands; and this fact just reflects the limitation of analysis itself.
Quoting John
You do realize hallucinations, illusions, and dreams exist, right? Do you also see there being no sense in asserting the existence of hallucinations? I assume not. So we have here a case in which we DO NOT have direct access to physical objects as they are, and yet we are perceiving something. What are we perceiving? We see things in our dreams which are not physical objects. We perceive all manner of illusions where there is no physical correspondence. There is no physical thing moving here, and yet we perceive movement:
Quoting John
You don't seem to understand representationalism/indirect realism. Representationalists hold that both "brain images" and physical objects exist. They hold that what we have to access to are "brain images", which are internal representations of physical objects in the external world.
It would appear to me that you're suffering from a bad case of naive realism, and don't really have a basic grasp on the various theories of perception. The following article is a good introduction:
http://plato.stanford.edu/entries/perception-problem/
No, I understand all the arguments for indirect/representational realism, and I find them inadequate and even self-defeating
.
Firstly if all we know is representations of objects and not objects themselves then there is an unbridgeable gulf between the object and what is represented; the objects becomes infinitely distant from us. This leads to an inescapable radical skepticism.
Secondly, the scientific analysis of perception that indirect/representational realism is based upon must be assumed to give us accurate information about the physical world or else indirect realism cannot be, and indeed no theory at all can be, justifiably based upon it. That the analysis of perception does give us accurate information about the physical world and its objects relies on the assumption that we perceive the physical world and its objects as they are. We have direct access to the world, in other words, and this is direct realism. The scientific analysis of perception, if it is believed to be accurate, can support only direct realism; if it is not believed to be accurate it can support nothing.
Thirdly, the indirect realist claim that we do not have direct access to objects means that perception of objects is somehow distorted by the process of perception. But this unintelligible because it posits a real object which is completely unknown to us on the one side and our distorted representations of it on the other. But a real object conceived like this can be nothing at all to us. Conceived like this it is not the empirical object, but the noumenal 'object'. But to even speak of objects in the noumenal 'context' is incoherent, and is merely a logical convention. The function of the noumenal 'context' is rightly reserved as signifying the absolute mystery of being, not the unknowability of the empirical object.
If the lights were out, then could we see through the object? Does the quality that allows the object to interact with light the way it does, if light were in the environment, change when there is no light in the environment?
This depends on what you mean by "know". Knowledge isn't the object, it is about the object. We know about objects by their representations. Knowledge itself is composed of sensory impressions.
Quoting John
You're missing something very important: Natural selection. Through the process of natural selection, more accurate interpretations of sensory impressions are favored over less accurate ones, which builds up exponentially to the detail and accuracy we humans experience with our sense of vision and other animals experience with their sense of hearing or smell.
On the contrary, you're missing the very important point; that is if we do not have direct (meaning undistorted) access to the physical world via perception, then the theories of evolution and natural selection fare no better than the scientific theory of perception; they would also be based on distortions.
I agree, indirect realism logically collapses into idealism. Because the external/physical world for the indirect realist doesn't really have an explanatory value. You would be positing an entire 'level' of reality (mind independent world) in order to explain the existence of your conscious experience, but you can have no real knowledge of this mind-independent world because it's beyond what you can access. You can't even know that it causes your conscious experience, so there's no point positing it because it doesn't have any explanatory value. The indirect realist should just become an idealist and analyse the physical world as merely being a concept or idea in the indirect realists mind and has no actual existence.
People like Thomas Metzinger however do flesh out ("Being no-one: The self-model theory of subjectivity") the indirect realist theory, and give a physical, scientific account of our conscious experience under the theory of representationalism. He claims his theory can be tested scientifically and has predictive value.
Quoting John
The indirect realist believes/assumes his representations are accurate depictions of the external world. Your argument only works if you believe representations are not accurate.
Anyway, going back to the thread topic, for the direct realist (you), the question is whether in the external world glass displays an image on its surface, or one can directly perceive the objects behind it. You seemed to argue that because I have not given a physical account of how glass displays an image on it's surface, it therefore cannot be possible:
Quoting John
Firstly, ulexite displays an image on its surface and this is uncontroversial. Do I need to present a physical account of what makes this happen before you believe that there's an image on the surface? Just go buy some ulexite and see for yourself. It's uncontroversial that some physical things can display an image on its surface. All I'm doing is extending this physical phenomena to include all transparent things.
Anyway, if we take what you've been saying - that we perceive objects in the external world, *as they are*, then there's a contradiction here because glass distorts and refracts the way in which see things. We don't see things through glass *as they are*. Fish seen under the surface of water, are not actually in that location due to refraction. So if you're perceiving the fish *as it is*, then how does this make sense because you're not seeing it in the right location. The fish can't be seen in one place, but actually be in another, and yet you are seeing the fish *as it exists in the external world*. Just look at all the illusions associated with clear objects I've posted on the previous page. Are we really seeing the world *as it is* directly when we see these illusions/distortions? Go to a hall of crazy mirrors, if you're seeing yourself *as you exist physically* then your head exists physically as a warped objected with a head the size of a beach ball and a pinched in nose, with wavy shaped arms, and also your body constantly drastically changes shape physically, from being super wide to super narrow to super tall and stretched to bunched up and tiny.
Again, your argument doesn't account for dreams, illusions, and hallucinations. We don't see physical objects in the external world *as they are* when we have these experiences. So what do we see? Some sort of mental construction, some percept/experience generated within the brain. The movement illusion I posted on the previous page is an example of this. There is no physical thing which is moving, and yet we perceive movement. Seeing as though there's no movement in the physical world and yet we are perceiving movement, the movement we see must be some sort of brain generated experience/perception. We are not seeing the world *as it is*.
So what I'm doing here is, fitting my theory into a direct realist account of perception. Either the image is on the surface of the glass, and we directly perceive it in the external world, or you see through glass at the object behind *as it exists* - and if this is so then the world seen through rose tinted glass must be physically pink. The man i posted in the swimming pool must therefore physically exist with his head completely separated from the rest of his body. If you take LSD and perceive the world warping and moving and covered in shifting geometric patters, is this how the world physically exists? No.
Not even direct realists hold that when we see illusions or hallucinations (or have dreams) we are seeing the world *as it exists*. This is the difficulty with naive/direct realism, in that it really struggles to account for these. The direct realist is in this position of asserting that only a very particular type of perception gains him direct access to how the world physically exists (obejects seen in the daytime, with clear lighting, while not being under the influence of drugs or have an sort of perceptual illness, including bad vision, and you can't be perceiving an illusion, mirage, hallucinating or seeing through clear things). What about the perceptions of animals, or even babies? They wouldn't perceive the world at all like we do. Why does the way you perceive the world give you direct access to how the world really exists outside yourself, but yet, how say a fish or dog or any other organism sees the world doesn't allow it to see the physical world as it exists? Why is your visual field a direct perception of the external world but the fishes not? And if the fish does not see the world as it is then what does it see? An internal representation? This is a very human centric view.
I'm not quite sure what you mean. If I'm understanding the question right, I would say that no, it being dark does not allow you to 'see-through' the object at the world behind it. In both the cases of it being light or dark, you would still be seeing an image on the surface of the clear object. You would just be seeing a really dark image on the surface of the clear object.
When we dream, remember and so on we don't see anything, we imagine things.
Quoting dukkha
If the indirect realist believes that then their position is no different than the direct realist's who does not deny the veracity of the scientific model of perception. Also, I think the term 'representation' itself conveys a misrepresentation of the situation. Objects are presented to us in perception; not represented by it. Objects act on us so as to become present; and they cannot be present in any other way. If objects were represented by perception then it would follow that there must be originals that are being represented and this is an incoherent idea.
A representation of an object is a model of it created through conceptual analysis; and that is simply not what perception does.
No matter what we say it will not be the real situation, but only more or less coherent and consistent with our experience and linguistic usage, and hence more or less adequate.
You can fit your head into the cosmos, but you will go insane if you try to fit the cosmos into your head. ;)
You seem to think that distorted means completely and utterly inaccurate. I see accuracy in degrees, not a simply black and white, accurate and inaccurate. I simply point to the fact that you are alive right now as evidence that you know enough truths about the world to not just survive in it but to procreate, communicate, make predictions, travel about, find things you've lost. You can function in this world for a long period of time. Try doing that without any knowledge or knowledge so distorted that there is no correlation between what you experience and what is out there. I point to the fact that we can communicate and understand each other even though we have never met each other and have different backgrounds as evidence that we both hear and see very similar things and engender very similar meanings from these written symbols.
Only if there was a limited amount of light could you see anything. I'm talking about utter darkness. No light at all. Have you ever hear of the phrase, "it's so dark I cant see the hand in front of my face"? I'm talking about that dark.
Why is it that you can't see anything, transparent or not, when there is NO light and why you see such vividness and detail when there is plenty of light? Why does the level of detail and vividness seem to correlate with the level of light in the environment?
Light A reflects off the object and forms an image on the surface of the 'transparent' material. Light B reflects off the image and is seen by the eye. But this raises two paradoxes ...
Light A passes from outside the material to hit the object yet the reflected light A does not pass through the material to outside it but stops at the surface to form an image. How can this be? Either the surface stops light or it does not.
Light A reflects uniformly off the surface of the object to form the image on the surface. Light B reflects uniformly off the image to transmit the image to the eye. So what is the source of the distortion? There should be a perfect image of the object and the eye should see that image perfectly there being no source of interference in either light path.
There being no rational solution to these self-contradictions it cannot be the case that we are seeing an image on the surface of transparent or translucent materials. There being no such paradoxes in the usual explanation ...
... that reflected light travels through the surface of the water but on a diverted path I must suggest that, until a better explanation comes along, it is irrational to favour your own explanation.
As I phrased it in the post you're responding to, the second one should be (B2) "having a property that enables seeing the object behind the transparent object." That's different than (B1)"being able to see the objects behind the physically transparent object," because in (B2), the subject of the phrase is the object, not our perception, even though we're saying something about a property of the object relative to our perception, whereas with (B1) , the subject of the phrase is our perception.
It's my contention that (B2) is not only what's functionally going on with talk about transparency and "see-thoroughness," but that that's what people typically have in mind with "see-thoroughness." And thus it's my contention that arguing against anything else is arguing against a straw man.
Quoting dukkha
Yes, which is what I think, too, but what it is to see objects behind the glass is that light passes through the glass, and light waves/photons stimulate your eyes, etc. Again, suggesting that people typically think otherwise, including us naive realists, would amount to arguing against a straw man.
Quoting dukkha
When I talk about stuff like this, my intention isn't to follow the conventions of any discipline as a set of social practices. I'm a physicalist or "materialist," so I'm going to believe that there aren't separate domains in ontological terms.
It occurs to me that it takes a deranged zealot to claim that optical fibres don't transmit photons, particularly when used in ultra-secure quantum communication applications.
You seem to be wanting to make a point against what I have said, but I cannot for the life of me see what it is.
If you are correlating the level of accuracy to the directness or indirectness of our access to the world, then direct realism would have to account for our mistaken impressions that we often have. If direct access means ultimate accuracy and indirect access means ultimate inaccuracy, then it seems to me that the solution is somewhere in the middle because we experience both accuracy and inaccuracies in our interpretations of our experiences. In other words, as I said before, accuracy isn't black and white. We can be accurate much of the time but still make mistakes. This shows that we have some level of indirectness but not so much that we can't know anything about the world.
"Mistaken impressions" just means "mistaken ideas" not "mistaken perceptions"; when we see the bent stick, our seeing of it is exactly what you would expect given that the light reflected off the surface of the stick is refracted by passing from one medium to a different medium. Even when we know the stick is really straight we continue to see it as bent, but this is not a mistake; that is just how it should appear.
We can have wrong ideas about how things work; in fact none of our ideas about how things work are absolutely infallible. That is because our ideas about how things work are ideas of causation; that is ideas of forces which cannot be directly observed.
On the other hand we cannot have mistaken ideas about how the world appears. Everything we know tells us it mostly appears just as it should. It is true that our imaginations may sometimes be projected out into the world; but that is something else.
Your diagram is not correct because you forgot the refraction of the light caused by the water, and Light B continues to travel below the water, because water is physically transparent. Light A is the light which actually reaches the retina. I drew the diagram correctly here:
If the image is too small to read just click on this link: larger image of diagram above
Quoting Barry Etheridge
No. Light A doesn't stop at the surface, it continues on and reaches the retina. We then see an image of the object which is on the surface of the water, but it appears at a depth below the water. A stereogram has the same sort of function - whereby what's seen *appears* to be at a depth beyond/below the surface of where the stereogram is printed/displayed on. That is, below the paper where the stereogram is printed on, or below the computer screen on which it is displayed, both of which are flat, 2D surfaces. The *appearance* of depth is just an illusion, you aren't actually seeing something which is behind the stereogram, you aren't seeing behind the paper or computer screen that the stereogram is displayed on. It merely appears that way to you. In reality what you are actually seeing is the surface of a flat object (eg paper or computer screen)).
Quoting Barry Etheridge
In your diagram you forgot to draw the refraction caused by the water. Light A travels from it's source (eg the sun) to the surface of the water. Because water is physically transparent this means that Light A can travel through it (at a refracted angle). Light A, travelling at a refracted angle, reaches the object below the water and is reflected at a perpendicular angle up towards the surface of the water. The light then stops being refracted because it has reached the air, and so travels at a different angle towards the eye.
Quoting Barry Etheridge
Well, yeah there is. We don't actually need to debate this now because it's a separate issue, but there is a paradox for the direct realist, of the eye needing to function in two completely different ways in order for direct realism to make sense. Those two ways being - the scientific biological function of the eye, and how the direct realist wants the eye to function as 'windows upon the world' which are being looked *through*.
If we look at the biology of the eye, all it does is focus, using the lens, incoming light upon the retinal cells. All retinal cells do is send off (essentially) an electrical charge in response to a light wave being detected. This electrical charge/signal travels through the optic cord and into the brain along a massive series of neurons, eventually reaching the visual cortex. The point being that there is no outgoing process here. Light travels to the retina, electrical charge travels into the brain. There is no means here by which one looks back out at the world. It doesn't make sense. The direct realist however thinks that our eyes are like 'windows upon the world' which we look 'through'. But this isn't supported by the biology of the eye. There is nothing which goes through the eye and back out into the world into the opposite direction towards which the light came in. Nothing goes back in that direction. And yet the direct realist understanding of vision assumes that is the case. The direct realist thinks when he looks at something, it's like an arrow travelling from his eye to the object in the world, as if his gaze goes from his eye to the object in the world and he sees that object in the world. But our scientific understanding of the eye (and the entire visual sensory system) does not support this at all. There is no outgoing process. Light travels to the retina, retina sends of an electrical charge into the brain. So through what means does your gaze travel back from the electrical charge in the brain, to the retina, out the lens of the eye, through the air and reaches the objects in the world? There is no biological means by which this could happen.
It doesn't make sense at all. Which is why in this thread I have repeatedly argued that the scientific/biological understanding of the visual sensory system entails *indirect* realism. Which would involve light in the physical world travelling to a retina, an electrical charge then travels from the retina into the brain towards the visual cortex. A visual perception is then generated by the visual cortex, which is what we visually experience. Our visual field would be located within a brain (because it's internally generated within a visual cortex), and what we see would not be the physical world directly, as if our eyes were windows upon the world, but what we see would be onboard (a brain) internal representations/model of this external physical world, located within the brain. The physical refraction of light occurs in the external physical world. What we see is an internal representation of this. So we couldn't point at a bent stick in water and say "that water *there* is refracting the lightwaves". Because all we are seeing is an internal (within a brain) representation of the physical refraction existing outside our brains in the external world. The physical refraction isn't happening in the water in the cup that we see, rather the physical refraction occurs in the physical external world outside the brain. We merely see an internal representation of this physical process.
Yawn...
I really don't know you're having such trouble with reading comprehension. I have *repeatedly* stated in this thread that physically transparent objects allow light to travel through them.
I have visual experiences in my dreams. But regardless we DO see hallucinations and illusions. You conveniently skipped over these.
Quoting John
No, there's a huge difference between seeing a physical object directly, and seeing a representation/model of a physical object. It's the difference between a map and a territory. No matter how accurate a map is, it's still not the territory.
Quoting John
You're just asserting this. Why is the "thing-in-itself", "noumena", "mind-independent object", an incoherent idea?
Quoting John
But you can fit a model/representation of the cosmos within your head. For the direct realist, a physical brain exists within an external noumenal reality. Physical neuronal processes within that brain generate/cause ("are equal to" if you're a type identity theorist) an experience of a phenomenal world, which is what the indirect realist has access to.
You are arguing that when someone says an object is "transparent" or ''see-through'', what they mean is that the object has a property which enables seeing the objects behind the transparent object.
Ok, sure. But the point of this thread is that physically transparent objects don't actually have that property. People may think they do, but they don't.
[/quote]'m pretty sure they just see glass, and believe they're seeing the objects behind the glass.
— dukkha
Yes, which is what I think, too, but what it is to see objects behind the glass is that light passes through the glass, and light waves/photons stimulate your eyes, etc.[/quote]
Can you finish this ''etc'' and actually outline how it is you think visual perception works? Because I'm pretty sure all you're going to say is, ''light travels from a source towards the glass, the light then travels through the glass (at a refracted angle) to the other side and carries on towards the eye, the light then travels through the lens of the eye and is focused upon the retina, the retina responds to the light wave by producing and sending an electrical signal, a signal which then travels through the optic cord and into the brain along a massive series of neurons, eventually reaching the visual cortex, and then we see the object behind the glass in the physical world."
What's actually happening in the italics? Whereby we've traveled from processes within the visual cortex to way back out into the physical world beyond the brain. How does this happen? I argued earlier in this thread that there is no (known) biological mechanism by which this occurs, and so the physical account of perception entails indirect realism. As in, ''...electrical signal which travels through the optic cord into the brain, eventually reaching the visual cortex, which then creates/generates an internal (within the brain) visual representation of the glass in the external world. And this internal representation is what we perceive.
Quoting Terrapin Station
Phenomenology is the philosophical study of the structures of experience and consciousness. It doesn't have any ontological commitments. What I meant by ''separate domains'' is two different disciplines, or areas of study. In the domain of physics, we study and describe light waves, mass, etc. In phenomenology we study (or really, analyse) our visual 'quales'. A physicalist should have no trouble practicing both disciplines. There's nothing contradictory about the two (well, unless you're an eliminative materialist!).
What point are you getting at?
But the stick isn't bent, the light is. We don't see sticks in water. We see light. We are informed of sticks and glasses of water by the light that enters our eyes. When you see a bent stick, do you feel a bent stick also? How is it that two different senses give you different information? Because we are using two different means of obtaining information about the world - one by using the repulsive force of electromagnetic energy (touch), and the other by using the wavelength and angle of electromagnetic energy entering the eyes. Our sense of touch is more direct than our sense of vision because it doesn't use electromagnetic energy at a distance. Why would it be useful then to use reflected EM energy from a distance to inform us about the world? Because it is often useful to know about objects, especially dangerous ones, before they are right next to you and eating you.
We see objects indirectly. We see light directly, or at least more directly than the object. This is what I mean by directness and indirectness coming in degrees. Light itself isn't colorful. Color exists only as a representation of EM wavelength in the brain.
Also our visual experience provides a perspective - of the world located relative to the eyes, but the world isn't located relative to the eyes.
I don't understand why you're adding the part in italics. It's not "and then we see . . ." It's rather "the above description (more or less, just because we're not worrying about whether each of those details is correct--for example, your nervous system doesn't just work via electrical signals, it's electrochemical) is what seeing an object behind the glass is."
In my opinion, which unfortunately I don't know how to relay here so that it doesn't come across as patronizing, you don't understand what naive realism is, especially in contradistinction to representationalism. I tried to explain this before, and I believe in this thread, but I don't know if anyone really read or commented on it.
Per your description immediately above, the difference occurs only with respect to the "creates a representation" part. The analogy that I use is that naive realists believe that the process is more or less like photography. Representationalists believe that the process is more or less like painting.
We agree on everything up to "reaches the visual cortex." Naive realists believe that information changing the state of the visual cortex IS perception/awareness of externals--there are no additional steps involved. The process is analogically like light entering a camera and creating an image on film.
Representationalists, however, believe that once the information reaches one's brain, there's another, unconscious process that occurs, whereby your brain then more or less executes a "painting" based on the information it received, where one can't know the relationship of fhe image in the painting to the information that precipitated the painting (is it a photorealist painting? Abstract expressionism? Impressionism? Etc.) And then what one perceives (I'd say "perceives" really) is the painting that one's brain unconsciously (or preconsciously) executed.
That the amount of information we acquire about our environment visually is directly tied to the amount of light in the environment.
Quoting dukkhaWhat would it be like to see an object directly? Seeing entails using light as a source of information about the world? If you are experiencing the object directly, then you aren't seeing it, you're touching it, and even then that isn't direct, but is more direct than our sense of vision. We can see both the map and the territory thanks to light. No light, no map or territory - at least visually.
Turn the lights on inside and now you have light traveling through the window outwards towards your eye and you can now see inside. Being inside the dark house, you can see through the window because the light is outside traveling through it, but me being on the outside there is no light traveling through the window towards me because I'm on the opposite side of the direction of light.
Transparent objects appear dark when there is no light traveling through, nor being reflected off of them (because they are transparent) from the other side towards my eye. So it all depends on where you are relative to where path of light.
That's indirect realism though. Camera = body/eye. Roll of film = brain. Image is on the film, which is located within the body.
It doesn't matter how accurate/photorealistic this image is, it's still an image. It's still not the physical world which exists in the world outside the camera. Clearly it's you who doesn't know what naive realism is.
The directness/indirectness comes into play as a result of the length of the string of causation. How many steps are there from point A to the last step?
As I explained, our sense of touch is more direct than our sense of vision because we physically come into contact with the object when we touch it. This isn't the case when we see the object. The object doesn't touch our eye (that would hurt). Light touches our eye and we are informed of the object's properties and state via the light that reflects off of it.
The reason why we can rely on the image representing the object's state fairly accurately is because the whole process is lawful, not random. Just as tree rings indirectly inform us of the tree's age, the tree rings were caused by the lawful process of the tree growing throughout the year. So we can rely on tree rings representing the tree's age accurately because they were formed by how the tree grows, which is a lawful, non-random process. We can also rely on our sense of vision because the whole process is lawful and non-random and the same string of causes ends up leaving us with the same experience.
If you believe your visual field is located within a brain you are an indirect realist.
Your perception occurs in your brain, or it "occurs of your brain." Again, direct realists are not saying that perception doesn't involve perception. If you believe that they're effectively denying perception, which is a mental process, then you don't understand what direct realism is.
The direct realist position involves the mind being out of the brain and in the world. Their understanding of how vision works, for example, is "light waves travel to the retina which send electrochemical impulses into the brain.... and then one looks at objects in the external world. The eye, for the direct realist are 'windows upon the world'. No perceptions are located within the brain for the direct realist. Sounds for example, are located within the world. The ear and brain just allow the direct realist to perceive the sounds in the external world. The sound perception isn't in the direct realists brain. Colours, the actual way things look (red,blue, etc quales) are for the direct realist located out in the external world. The eye and brain are just a mechanism by which these external existing colours are perceived. The red, blue, green look to things are not located within the direct realists brain, they're out in the world. For the direct realist externally existing objects are literally presented in their experience. The mind essentially superimposing itself upon things in the external world. The 'look' of things exist in the external world. As in the red cup literally still 'looks' red even when it's in the cupboard. The mind just allows one to have access to how the cup looks in itself.
From Stanford Encyclopedia of Philosophy:
[quote=SEP]Direct Awareness of Material Objects
Before considering whether a case can be made for the second direct realist thesis, we need to look a bit further at the first thesis. How are we to understand the claim that we are “directly” or “immediately” aware of material objects? Here there are at least two initially plausible things that a direct realist can say. First, contrary to what a representative realist view might seem to suggest, our perceptual awareness of material objects is obviously not, at least in ordinary cases, arrived at via anything like an explicit inference from either beliefs about or awarenesses of subjective entities such as sense-data. On the contrary, in most ordinary situations, it is material objects and situations that are the primary and usually the exclusive objects of the perceiver's explicit awareness and thought, with no hint that this awareness has been arrived at via any sort of transition from anything else. Second, as Searle and others have argued, there is an obvious and intuitively compelling way in which perceptual experience seems to directly present physical objects and situations. Direct realists have sometimes spoken here of “openness to the world,” a locution that suggests the way in which such objects and situations seem to be simply present in their own right in experience. The direct realist need not deny (though some have seemed to) that sensory experience somehow involves the various qualities, such as complicated patterns of shape and color, that sense-datum or adverbial views have spoken of, nor even that the perceiver is in some way aware or conscious of these. His point is that whatever may be said about these other matters, from an intuitive standpoint it is material objects and nothing else that are “directly before my mind” — and that any view that denies this obvious truth is simply mistaken about the facts.[/quote]
The direct realist is not aware of perceptions which are located within a brain. When he sees a red cup, the 'redness' which he perceives is literally located within the external world. The eyes, brain etc are just a mechanism that allows one to have direct access to the externally existing 'redness'. The redness is NOT located within a perception within a brain! That's the position of representationalism or indirect realism. It does not matter at all how accurate the perception which is located within the brain is. It could literally be a 1:1 copy of the external world. Because it's still a copy!
Anyway, this debate has gone so far off topic. The direct realist would see an image on the surface of clear objects, which is located in the external world. For the direct realist the image would still be there even if nobody was around. (He doesn't realize it's an image though, because it's so 'crisp'). You might say you can't believe there is an image there because there's no plausible physical way by which glass could display an image. But, it is uncontroversial that this is exactly what ulexite does. Ulexite has fiber optic properties which cause an image to displayed on its surface. Same sort of thing is happening with all other physically transparent objects (objects which allow lightwaves to travel through them).
No. Sounds only exist in the mind. Vibrating air molecules are located within the world and sound is a representation of those wavelengths of air molecules. Just as colors don't exist out in the world, they only exist in the mind as representations of wavelengths of light. We don't see wavelengths of light, nor hear vibrating air molecules. If we did, that would be direct realism. We don't, which is why indirect realism is the case.
Quoting Terrapin Station
And what I've been saying is that perception comes in many different forms. We can perceive the world visually, audibly, and via our sense of touch, taste and smell. I have already pointed out that different perceptions can give us different information about an object - like the straw visually appearing bent, but our tactile perception informs us it is straight. If direct realism is true, then why would we have two different perceptions of the same thing? Which perception is accurate?
Direct realism conflates the way things appear and the way they actually are. We don't see wavelengths of light. We see colors.
When Nagel asks "What is it like to be a bat?" Is he asking what it is like to actually be a bat, or what is it like to appear to be a bat?
Well, first it's important to remember that direct realism doesn't claim that there are no illusions, or that there is no faulty perception. But aside from that, re "which perception is accurate," the answer is "all of them."
There seems to be another popular straw man in discussions about direct realism online that has it that direct realists are for some reason asserting that one perceives the "entirety" of the objects and phenomena that one perceives. No one is claiming this. For example, when we say that we directly/accurately perceive the moon visually, no direct realist is saying that they also perceive the dark side of the moon visually (with the naked eye on Earth).
So it's rather the case that we're perceiving some subset of properties of the objects and phenomena at hand, and per my idiosyncratic views here, we're perceiving a subset from a particular reference point, where what we're actually talking about is a complex or system, because we're talking about a lot of interacting factors, such as light traveling through an atmosphere. Continuing with my idiosyncratic views, it's also the case that everything is always a particular way at one reference point and (at least some) different ways at different reference points (where I'm talking about actual properties, not (just) perceived properties), and "there are only reference points," or in other words, it's impossible to escape reference points.
So per touch, x is like a, and per vision, x is like b, and so on, and all of those are accurate (ceteris paribus) because they're different subsets of properties. And also, per touch, x is like a to S at reference point 1, and per touch, x is like f to Q at reference point 2, and so on. No two people can experience something from the same reference point, and even the same person can not experience something at the same reference point multiple times, because reference points are unique to time-slices as well as spatial locations.
Just splitting hairs here but this is not entirely true. Check out this illusion for example, the same wavelength of orange is striking our retinas but we perceive two different colours:
Objects which appear blue in the day still emit the same 'blue' wavelengths of light at nighttime, just not enough for the cones in our retinas to respond to.
[quote=]No. Sounds only exist in the mind. Vibrating air molecules are located within the world and sound is a representation of those wavelengths of air molecules. Just as colors don't exist out in the world, they only exist in the mind as representations of wavelengths of light. We don't see wavelengths of light, nor hear vibrating air molecules. If we did, that would be direct realism. We don't, which is why indirect realism is the case.[/quote]
Ok. Getting back to the thread topic the question is then, does the brain internally represent physically transparent objects by producing a visual perception of an image displayed on the surface of a transparent object, in much the same way as the brain internally represents ulexite? Or, is the depth which we perceive in glass not an illusion, and the brain is producing a visual representation of the physical objects which exist behind the physically transparent object?
Or, to speak poetically, what is the 'length' of the visual field which the brain produces. Does the visual perception span from your eyes to the surface of the glass, or does it span beyond the glass to the objects behind it? So, when the brain internally represents ulexite, the 'length' of the visual perception is from the eye to the surface of the ulexite. Is it the same for other physically transparent objects (physical objects which allow light to pass through them).
Well, how do you know you're touching an object? Through sight. But if your sight is indirect then the object you are touching is an internal representation. If you look at the biology of the sematosensory system this makes sense as well. There's nerve cells in your skin which fire off neuronal impulses (in response to various stimuli) to the spinal cord, where some processing may occur, the impulses then travel to the brain for further processing. In much the same way as there's only an incoming process for the visual system (retina responds to light and sends impulses into the brain where a visual perception is produced, i.e. an outgoing gaze isn't then produced which goes in the opposite direction beyond the brain and into the external world beyond), likewise nerve impulses don't travel from the sematosensory receptors to the brain, and then you directly feel the physical object. It's more like in the brain there's an internal model of the body and the brain collates all the different data coming from the various sensory organs into this model. The touch perception exists internally within the brain, the objects which you see yourself touching are internal visual representations of physical objects in the external world.
Heres a representation of a cortical homunculus. It shows the parts of the brain which are devoted to sematosensory data coming from those particular regions of the body. Note how the fingers take up far more brain power than say, the back. There's a far higher density of sematosensory receptors in the fingers compared to the back.
This is what's entailed by indirect realism. You don't have indirect access with some senses and direct access with others. Rather the brain produces a cohesive onboard self/world model, which is what you have epistemic access to only. The world around you, your body, other people, it's all an internal (private) representation. You exist entirely cut off from the physical world.
Direct realism redefines illusions out of existence. If illusions are what you are suppose to experience as a result of particular causes, then you aren't experiencing an illusion. In fact there are no illusions. There are simply misinterpreted sensory experiences.
Quoting Terrapin StationThat isn't my argument. I'm not arguing that we don't see an object in it's entirety and that entails indirect realism. I'm arguing that we have contradicting information about one object and that is evidence of indirect realism.
If I were entirely cut off from the physical world, then how do I experience it? You are promoting dualism without the explanation as to how the mental can interact with the physical.
There is no mental vs. physical in the world other than as categories in the mind. The world is just one substance - one of information - where information is simply the relationship between cause and effect. The cause is not the effect but they are linked by time and space and exist together within the same medium. What we experience is the effect. The cause is "out there" in a different place and time. We can only experience the effect and never the cause, which is why indirect realism is the case, yet they are linked so as to prevent any separation that would require an explanation of how one can rely on their experiences being informative.
Quoting dukkhaThen how does a congenitally blind person know when they are touching an object?
The point is, and this would have been clear had you understood all of my comment, that the information doesn't contradict. For one, when we're talking about different senses, obviously we're talking about different information-- visual information is different than tactile information, for example; light waves are different that surface textural properties, etc. Hence why I noted that we perceive information about some properties, where that's different on different occasions, etc., and via a "complex" or a system--things aren't in, and we're not perceiving them in, vacuums.
I don't know why you're claiming that direct realism dispenses with illusions. It explicitly does not.
Re the comment about it being something other than direct realism, again, this appears to be a case of simply not being familiar with or not understanding what the conventional distinctions between the two are.
We're not talking about different information. Both senses provide different representations about the same thing - the shape of the stick. What is the shape of the stick?
So the real question is, is how something appears how it really is? We're asking about the difference between a representation and reality. What we have direct access to is the representation, not the reality. The reality can only be accessed indirectly through it's representation. So if it is your argument that we see exactly how some thing appears then you are still saying that all we have direct access to is a representation, not the reality. So, at best you can call your stance direct representationlism, not direct realism. There could never be anything like direct realism. Effects are not their causes. Effects are the result, or the emergent property, of various causes coming together.
How an object appears doesn't just provide us information about the object, but also about the amount and wavelength of light in the environment and also about the state of your visual system. All of these things are represented in the experience of the color blue.
If you can only get at the "realness" of an object by how it interacts with other things then either the object doesn't exist independently of it's interactions with other things, or you can never get at the object as it exists independent of it's interactions with other things. This why direct realism can never be the case.
But this is just what I was talking about in my comment. The properties of everything extant are relative to the reference point we're talking about, and there are no "reference point free reference points." In other words we're always talking about some reference point or other, and that reference point is different than other reference points.
And we are talking about different properties, because we're talking about light waves and how they react with something as part of a system versus "topological" surface qualities and how they interact with different things. That's what the world is really like. It's not really like some abstracted simplification where you pretend that properties are not relative to reference points and so on.
We're not talking about different properties. We're talking about one property - the shape of the stick. What is the shape of the stick independent of any senses accessing it? Does the stick have a shape independent of any sensory system accessing it? Does the stick exist how it appears in my mind or is it something else? Does the stick exist when I'm not accessing it via any sensory system?
If that is what the world is really like then you're an idealist/solipsist? It seems to me that it is what perception is like, not the world, and perception is only one process out of many that make up the world - a process that creates colors and sounds which don't exist in any other part of the world except right here in our heads.
I don't believe that you're understanding me. Let's try it this way:
We're talking about the shape of the stick from what reference point?
No, it's you who aren't understanding me. I've asked this question numerous times and you've ignored it.
From no reference point. What is the shape of the stick when no one is using any senses to observe it?
As I explained a couple times, "from no reference point" is impossible.
So then the stick doesn't exist outside of a reference point? You aren't arguing for direct realism at all. You are arguing for solipsism.
Reference points have no necessary connection to minds, persons, etc.
Imagine that no people exist whatsoever. Everything that exists still has (at least some) unique properties at each unique reference point, and it's impossible to escape reference points.
Any "the stick is such and such" fact is from some reference point. Again, this has nothing (necessarily) to do with minds or people or anything like that. So it has nothing to do with solipsism.
This creates an infinite regress of reference points. Do reference points need other reference points for any reference point to exist?
What you are saying is that for anything to exist, there must first be a reference point. But what is a reference point without a perspective, or without a mind?
What about a view from everywhere (God's-eye view)?
Hence you not understanding my comments--which is what I said in the first place, but which you denied.
Quoting Harry Hindu
I'm not saying anything about temporal or logical priority.
Quoting Harry Hindu
Reference points are non-null sets of spatio-temporal locations.
Quoting Harry Hindu
The set of all spatio-temporal locations is a reference point, and not a privileged one. It's just one set of many. We can only talk about properties from the context of a particular set rather than subsets (of the given set) when the properties of the object or phenomena in question are consistent among those spatio-temporal locations. You can still call a larger set a reference point, but an object or phenomenon can have conflicting properties per subsets of a larger set. It's not that some of those properties are incorrect; it's just that they're relative to particular subsets of spatio-temporal locations.
Me not understanding isn't the same as someone writing gibberish. Non one can understand gibberish, except for maybe a lunatic.
Quoting Terrapin Station
What does this even mean? Care to clarify? It seems to me that you are describing reference points as something that doesn't need other reference points to exist. Is a reference point material, mental, or something else? Obviously our own reference points can interact, so reference points are something tangible.
Actually both of those would be situations where you're not understanding something. It's just that you're hinting at the idea that if something is understandable, then you'd understand it. It's always amusing when someone is that arrogant, although I don't find it as amusing that that is such a common attitude on message boards.
Quoting Harry Hindu
You'd need at least two for location to make sense.
Quoting Harry Hindu
Mental is material first off, so there's no difference there. Spatio-temporal locations are properties of and/or supervene on material and structures and dynamic relations of material.
The stick is straight. Looking at a stick does not change its shape.
Quoting Terrapin Station
Okay then reference points exist apart from each other. What is the medium in which reference points exist? What is it that ties two reference points together for location to make sense?
Quoting Terrapin Station
The god's eye view must be a privileged one for it is the one that maintains the properties of reality for other smaller reference points to access. This is no different from the idealist view that God is necessary as the eternal observer to maintain the properties of reality that the smaller reference points access. For if there is no eternal reference point from everywhere, then how is it that your post maintains it's properties until someone else reads it? Your post isn't being read non-stop 24-7, that is unless you want to amuse me with your arrogance that your posts are constantly being read.
Thank you, tom. I've been trying to make this clear to Terrapin, but he seems to be bent on tip-toeing around the answer by writing nonsense.
Reading comprehension assistance: "if something is understandable (to anyone), then you'd (personally) understand it.
Since you needed that reading comprehension assistance, clearly something being understandable to some people doesn't imply that you'd understand it.
Quoting Harry Hindu
Well, there's not just one, yeah. The fact that I've used the term in plural denotes that.
Quoting Harry Hindu
No medium.
Media are material, structures of material and dynamic relations of materials and structures. But that's all reference points.
Quoting Harry Hindu
People thinking about them being "tied together."
Quoting Harry Hindu
That's false though. There are no privileged reference points. What would privilege them? Nothing objectively.
Quoting Harry Hindu
Here you're suddenly talking about it as if it's your theory, which is weird. I don't know where you're getting the ideas from that you're forwarding there, but they're certainly not my ideas. "Smaller reference points" (as well as "larger" ones) don't "access" anything. And none of them are not reality. At least not on my theory. If you're instead forwarding your own theory, then okay. That's your theory and I disagree with it.
Quoting Harry Hindu
Okay, if that's your theory, but it has nothing to do with my theory.
Quoting Harry Hindu
If you want me to think that it's worth talking about this to you--which is something that I don't really believe at this point--you need to make some effort to read and try to understand my views. I explained way back there, and I explained more than once, that there at at least some different properties of all things from each unique reference point, each unique spatio-temporal location. So it follows from that that I'd not be arguing that a post has identical properties through time, from various spatial locations.
Haha re my comment about your arrogance getting to you, by the way.
Get your head on the rocks about 50 cm away from the edge of the rock pool, as close to horizontal with the surface of the rock pool. Basically lie down on the rocks next to the pool with your head sideways resting on the rocks. Get a stick, and poke it into the rock pool in and out of the rock pool while watching it refract.
Sounds fairly stupid, but from this angle it's really clear that the what you see as the lower half of the stick is actually an image on the surface of the rock pool. The water is not see through, and as the lower half of the stick goes into the water, it disappears below the surface. What happens is an image is displayed on the surface of the rock pool of the light travelling from the stick below the surface (light which is refracted) up to the surface. And this image is what you see.
It looks like the water magically melts and bends the stick. But in reality the stick stays straight and disappears below the surface and you see an amalgamation of the top half of the stick out of water, and an image of a (refracted) stick on a surface of water.
From the angle you're viewing the rock pool surface from (while having your head close to the rocks), the image loses a lot of it's depth, so that it becomes a lot clearer that what you are seeing is an image on the surface, and from this angle the degree of refraction is a lot greater than if your standing above the rock pool looking downwards and poking the stick in. The greater the amount of refraction, the more skeptical you become that what you are still seeing is the actual stick.
I think perhaps that what I'm outlining in this thread is just one of those things which you can't just debate someone into believing, they have to figure it out and learn for themselves. That clear things are see-through is such a fundamental belief we hold that it takes something pretty significant happening before you shed that belief.
Personally what happened is I became pretty obsessed with glass and mirrors for like two months, especially mirrors in the beginning. I just couldn't understand how the mirror could teleport my gaze behind myself, so that I could look forward at the mirror, and yet see something behind myself. Eventually I figured out a mirror just displays incoming light as an image on it's surface, but glass refraction still confused me. I remember, I would sit in my car and wind the window down halfway. And I'd look at the side mirror so half was seen through the air and half was seen through the glass. I'd move my head side to side and watch the glass bend the mirror, and wind the window up and down and notice the position of the side mirror shifts as you roll up the window. It kind of 'jumps' back and forward. Anyway, eventually I finally had the revelation while the window was halfway down that the side mirror seen through the air continues behind the window. I can't see it because the window displays an image on it's surface of the light coming from behind it, and I can't see past this image at the rest of the side mirror behind it. You have to roll the window down to actually see the rest of the side mirror. Absolutely blew my mind.
But now, I feel like I drive blind. I just sit in the drivers seat looking at an image on the windscreen, and I can't see past it. I wish it wasn't illegal to smash my windscreen out so I could actually see the road!
Sounds psychotic, I know :D But this is actually how glass works. Looks like it's just one of those things where you have to figure it out for yourself. Have your own 'eureka' moment.
(disguised bump)
The true believer speaks.
Just wait until your legal guardians let you plug in electronic devices. You'll be staring at the cords, the outlet etc. for years.