Intervenientes:
Ou aqui.
Ou aqui.
RLK:
Ned, I think consciousness is really important. What do I do with some very smart philosophers who tell me that consciousness is an illusion?
NB:
Well. The recommendation is to realize, first of all, that there are some casts of mind that want to regard anything that they don’t know how to understand, in their favourite way, as an illusion.
I think the thing to realize about consciousness is thst there are some very difficult problems.
One, is what is often called the “hard problem of consciousness”. That’s David Chalmers’ term (http://en.wikipedia.org/wiki/David_Chalmers) . Earlier than Chalmers it was called the “Explanatory Gap”, by Joe Levine. That is the problem of how i tis that the neural basis of a conscieous experience is the neural basis of that experience as opposed to some other experience or no experience at all.
There’s another problem I call the “harder problem”, which is the problem of other minds, basically, and that’s a problem of how we could tell, what would make it the case, that a creature made of very different material from us, made in a different way, like the famous commander Data of the Star Trek series. How we would know whether that creature is conscious. These are very tough problems, but they’re not problems that should make you think that consciousness doesn’t exist (1:28), that it’s an illusion!
Dan Dennett (ou aqui) wants to say that there’s nothing to consciousness other that a certain kind of function, but I that what’s important in understanding a hard phenomenon like consciousness is understanding what you know and what you don’t know and nos regarding what you don’t know how to explain as, therefore, illusiory.
RLK (1:54):
Well, he would say that we have these, so called, multiple drafts; that conscious is, sort of, “fame in the brain”, that whatever aspect of our sensory or thought processes gains priority for the moment, has the illusion of consciousness, but you really have all the paralel things going on that is all quite natural and normal and that we have imbued this activity with mystical consciousness idea as a kind of a cultural construct.
NB:
So what he calls “fame in the brain” is what I call “access consciousness”, which is jus tone kind of consciousness... It’s the aspecto f consciousness that plays a role in one’s cognitive life: thinking, noticing, etc. What he leaves ou tis what I call phenomenal consciousness: what it’s like to experience red as opposed to experience green. A familiar conundrum might be useful to explain the inverted spectrum, the possibility that things we both agree are green, look to you the way things we both agree are red look to me. We can all understand that. Children can understand it. My daughter at age seven, when I first mentioned this to her said (3:13), ‘Ah! That explains why some people don’t have the favourite colour purple!’ Really everybody’s favourite colour was purple, but for some people they just call it some other name because their spectra are inverted. So we all understand this idea. There’s no way it’s an illusion. What we have to do is we have to just clearly distinguish the cognitive aspects of consciousness from the basic biological phenomenal aspects.
RLK:
The argument to your argument says that what you’re doing is artificially inflating the concept of consciousness. Inflating a difference in degree, so that you now imagine a difference in kind.
NB (3:59):
Right. Well, if you look at differences in degree we can think about people, for example, who see, to one degree or another, on one extreme where people see perfectly and another extreme where people who are, so called, legally blind, that is, that they can just distinguish a few shades of light and dark. But that difference of decree is very different from what’s phenomenal and a good example to illustrate that is the phenomenon of blind sight (4:29). This ia a completely unconscious kind of visual detection. Someone who has the very back of the brain visual área, parto f ir destroyed, it’s called the área V1, in the back of the head, the first cortical área. Some people who had those áreas destroyed can, nonetheless, distinguish an “X” from an “O” or “up” from “sideways” in their blind field. If you ask them what they see, they say, ‘I don’t see anything’, and if you ask them to guess whether it’s an “X” or an “O”, they can guess almost perfectly!
RLK:
But they still think it’s a guess?
NB:
They still think it’s a guess. One of those patients had far better discrimination in His blind field, where there was no consciousness, than in His sighted field which was on the order of legally blind. So the difference of degree is the difference in phenomenology. Not a difference in detection or acuity. So I think Dennett is just wrong. The difference of degree in phenomenology is one that is quite orthogonal, different from the difference in accuracy which doesn’t go together with phenomenology.
RLK (5:41):
But wouldn’t that same discription of these differences show that, as we see different kinds of brain injury and radically different kinds of efects on consciousness and perception, indeed give credence to this multiple draft thing, idea, because you have all these different kinds of systems and inputs and if one or two get destroyed you see odd results, so doesn’t that actually support that view?
NB (6:10):
Well, the interesting thing is that some of those systems that you describe, some of them are conscious and some of them are unconscious. A dramatic example is the fact that all humans (6:21) and all higher primates have two different visual systems. This was basically discovered in this form by two neuroscientists, Mel Goodale (ou aqui) and David Milner (ou aqui) . What they were able to show is that there’s a system they call dorsal system at the top of the head that is oriented around action, towards planning, towards controlling your visually guided actions. But it’s unconscious! And another system, the ventral system (6:53), in the lower part, it goes from the back of the head into the side of your head. That is a conscious system that doesn’t have a direct controlo f action. So we have two different systems that do two different things. Maybe a way to see the systems is to notice that there are different brain injuries that have different effects. Somebody who has the top axial (?) oriented system destroyed can see things perfectly, in the sense of conscious vision but can’t act towards them. For example, if you have a male slot that can be tilted, the person can’t insert the card into the male slot, they’re completely at chance with that, whereas the other injury, which is a sad injury, and there’s a famous patient known as a “DF”, it’s called a visual form agnosia, she can post that card perfectly in the slot, but if you ask her what angle the slot is she doesn’t even see it. She doesn’t know! But she can act towards it perfectly. Some of those systems Dennett is talking about in multiple drafts, some of those systems are conscious and some are unconscious, which shows that the idea of multiple drafts doesn’t capture the essence of consciousness.
RLK (8:08):
So what, then, can we say about consciousness being an illusion? And what are the implications in either direction, if i tis an illusion or if it’s nota n illusion? What follows?
NB:
Well, if i tis an illusion in the way that Dennett thinks, then there is no hard problem of consciousness, there’s no harder problem of consciousness that I described. No problem whether how we would tell comander Data is conscious, we just look at the behaviour and the cognitive processes that produce it (8:40). Dennett is basically a behaviourist. He was taught by the famous philosopher Gilbert Ryle, who is an... Behaviourist. Dennett, sometimes, allows that he is. If consciousness is an illusion in that way, then there is no difficult problem with consciousness. It’s just a matter of doing what Chalmers calls the easy problem for just studying the function consciousness. On the other hand, if consciousness is nota n illusion, as I think, and some other philosophers and scientists think, then it’s really a matter of trying to work on those functions with an eye towards on how we might solve these very difficult problems. If... my advice to any scientist who wants to win the Nobel Prize, thinking about consciousness, is it’s better to recognize what you don’t know and not call consciousness an illusion.
Sem comentários:
Enviar um comentário