Since "sight" occurs in the mind, how do you know that you're really seeing what's in front of you?

Question

Sight has been proved to be a function of the brain. The simplest demonstration of this is to look at an object and then close your eyes and visualize the object. You "see" the object -- in your mind. This is because the brain learns to "see". If the brain is presented with something it does not know, has not learned to see, it does not "see" it, or "sees" it as something else. This is a fundamental concept with far ranging implications.

Yes, Chris M, you're onto it now. We do take in "packets" or "bits" of visual info.

Yes, all who mention it, it does have lots to do with the phenomena of illusions.

Sorry, Calivane, you missed the boat entirely. Have fun sniping back there in Tree Falls. Durrr durr durr.

Mereological fallacy -- valid point and one of many arguments/debates. I should add here that I've had a lifelong fascination with
the mind-body (brain especially but not exclusively -- look at the "houses of pain"
for example).

Answer 1

Hi ttoflea.

This is a really interesting question that you've hit on here, and in philosophy we call it "the problem of illusion". As an example, take a glass of water and put a straw in it - no matter how well your brain has "learned to see", you'll see the straw appear to break instead of go straight as it should.

AJ Ayer said that this proved that we never really see anything, but instead that our mind only senses what he called "sense data", that is, information that comes to us from our senses. So, when you look at the computer screen, you don't perceive the screen itself, but little packets of sense data that are passed from your sense organs (eyes, in this case) to your brain.

However, is this what we really mean when we say that we 'see' something? John McDowell doesn't think so (and I agree with him). Think about the double meaning of the word 'appear': if a beautiful woman appears to be in front of you, then perhaps she is, but perhaps she isn't; if a beautiful woman appears in front of you, then it could also mean that she has really appeared, that she is there. From this we can go on to realise that it's not possibly to actually see a beautiful woman unless one is really there - if one is not there, then in fact you saw something different, but mistook it for a beautiful woman.

The sense-data theory of perception depends upon the use of appearance as mere appearance, but this use is not necessary. Instead, a simpler explanation is that objects make themselves manifest to us when we have true perceptions. Though in a deceptive case, experiential intake falls short of the fact, in the sense that it is consistent that there is no fact, in veridical perception the object is actually manifesting itself, and thus the object of experience does not fall short of the fact. This enormous difference between illusions and hallucinations as opposed to veridical perception leaves no need for sense-data a “highest common factor” explanation, since there is no need to look for any common factors at all.

Hope that that helps: read JL Austin's book "Sense and Sensibilia" for a really accessible account of the theory (often called disjunctivism).

Answer 2

You know you are seeing what is in front of you from learned behavior and experience. That is why when we are babies, we put everything in our mouths and reach out to touch everything. Soon, you learn that the object you 'see' has dimension and is taking up a space and understand spatial concepts. You can find much research on this topic under the developmental stages of humans.

Answer 3

Sight might be the most powerful sensory input, but it is not the only one. Looking at a hot stove might not clue you in to the true nature of the stove. Touching the burner, hearing your flesh sizzle, and smelling it, will give you total awareness of the nature of the stove. Sight is an important tool to help us understand the underlying reality of the universe, as all our senses are. Learn how to use them, or perish.

Answer 4

It's a good point. If I shut my eyes, I can still see things, so how do I know I'm not "seeing things" with my eyes open?

We used to play a game with my dog. We would show him a toy and place it on the back of a chair or something, he followed it with his eyes and fetched it when told. When we just as deliberately and plainly put it on top of our heads (it was still clearly visible to us) it simply disappeared as far as he was concerned. He had watched it, in our hand, go up and appeared to have seen what we did with it but when asked to fetch it, he would look wildly around the room. Because he didn't expect toys to be on top of people's heads it had, to all intents and purposes, vanished.

Answer 5

If sight was only in the mind we wouldn't have blind people and white sticks. The brain interprets what the eyes see and stores it in memory - like your computer stores a picture from a digital camera. take away the digital camera and the computer only sees what it has stored - nothing new.

Answer 6

Well, let's see. I can also touch, feel, hear, smell, and sometimes taste things in front of me too, so I assume it is actually there.

These stupid "IF A TREE FALLS AND NO ONE HEERZ IT WIL IT MAKE A SOUND LOLZ" type questions piss me off. Back to the other questions that anger me. Later.

Answer 7

It becomes the philosophical problem with what do you mean by "Reality".
I think most humen beings accept its real if we can interact with our senses. But like in your question, we can also imaging the things what we interact in the past with our experience.
But there's the answer outcome, we can accept most of our senses are real if it also interact with others human as well as us. That's why someone ask to other "I don't believe it, Is it real??" to confirm, or make sure , s/he faced with reality.
But there'll be other definations as well.

Answer 8

You should read "The philosophical foundations of neuroscience," it deals with exactly this problem, which is called the mereological fallacy.

Answer 9

Ah yeah far ranging...go outside find a flower smell it see it touch it. Go back inside stop thinking about this stuff...

Answer 10

You get data from the other senses, so learn to trust your vision.