Thread: Can the brain explain perception?

Originally Posted by Dianeva

I don't see a problem with consciousness not existing. What do you think would happen if all life just died? The universe wouldn't cease to exist.

I'm not sure what this has to do with what I said. Without consciousness there would be no knowledge or subjectivity, which is what this conversation is about.

Originally Posted by Dianeva

I'm not assuming anything. I have reasons for thinking that consciousness is different, and I've explained them in multiple ways. Since I don't know how to explain it anymore clearly, I suppose we're done with this conversation.

You actually didn't. You just assumed it was and then wrote the reasons why we cannot figure it out.

Originally Posted by Wayfaerer

I'm not sure what this has to do with what I said. Without consciousness there would be no knowledge or subjectivity, which is what this conversation is about.

I read it wrong then, sorry. I was mostly responding to the last sentence, I was tired as hell though.

Originally Posted by tommo

You actually didn't. You just assumed it was and then wrote the reasons why we cannot figure it out.

Do you still think that if we knew everything about how a bat works, we'd be able to tell exactly what it feels like to be a bat? What if it were determined that a different thing happens in the brain than happens when we experience vision? It would be an experience incomprehensible to us, no matter how much we knew about the bat's brain. The sensation of the colour red cannot be explained to a red-green colourblind person. Whatever the colours red and green appear to colour-blind people is still a mystery even to optometrists and scientists with knowledge about the human eye.

It is not a mystery at all.

There are simple images you can get the colour blind person to look at, which indicates they would just see green as we see red or whatever.

And I already said, no we cannot tell what it would FEEL like to be a bat.

That's assuming a bat is vastly different from us. Which it really shouldn't be. Assuming it is conscious, we know what that feels like.
We know that it "sees" in the sonar spectrum, so it would be like we see, or hear, but just higher in the spectrum.

And I said there is no reason why that is weird, or an anomaly or anything. Of course you can't, because you are lacking some knowledge.
If you had all knowledge about it, you would have to have experienced being a bat.

The images shown to red-green colourblind people show that they can't distinguish between certain shades of red and green. They don't tell us how they perceive them. I had a colourblind bio teacher who said he can tell the difference between red and green, that they're different colours, but he has trouble distinguishing between them when the shades are close. We're shown images of sort of a murky green colour, which are the best guesses as to what they see red as, but they're really just guesses.

Why would we only not be able to tell what it feels like to be a bat, if bats are vastly different from us? What if they are? Then we wouldn't know what it's like to be a bat, and that would pose a problem. I can't figure out whether you think what things feel like should be determinable from knowing everything about the object, or not. You seem to keep changing your stance on it. One post you're saying conscious states should be determinable, and they are. The next you're saying conscious states shouldn't be determinable, and they aren't.

What about the light spectrum, and certain species' abilities to see UV light? No matter how much we knew about those species' brains, we'd never know what UV light looks like, even if we had all information.

Originally Posted by Dianeva

You seem to keep changing your stance on it. One post you're saying conscious states should be determinable, and they are. The next you're saying conscious states shouldn't be determinable, and they aren't.

No, you're missing my point.

"If you had all knowledge about it, you would have to have experienced being a bat."
By knowing how a bat's brain works, we obviously cannot know what it would feel like, because we couldn't FEEL it ourselves.

But that's because we can't get all the information, we can't know everything there is to know, unless we can become a bat.

The best we could do is relate it to something we feel based on how the bat's brain works.

Okay. Well it's been confusing because, when I've discussed knowing everything about a system, I've meant physically. When we know everything going on in a bat's brain - with the exception of having experienced what it's like to be a bat - we would not know what it's like to be a bat.

Subjective 'feelings' are necessary results of the physical components working together as they are. Seeing red as the redness that we do is a necessary result of those physical components.
So, we should be able to determine the effect, that redness, by examining the physical components.
But we can't.

You argue that we shouldn't know what redness feels like to perceive, if we know everything physically.
But that's only because you're taking for granted that there is a sensical difference between physical stuff, and what things feel like subjectively. You don't understand the problem - that subjective experiences don't make sense in the first place. If everything is physical, then whence comes this 'subjectivity', these real things like blueness that exist but which we can't have knowledge of no matter how much we know physically?