Wikipedia notes a definition of qualia: …qualia are properties of sensory experiences by virtue of which there is something it is like to have them.
Much of the debate over the existence of qualia lies in the definition of the term, so I’ll give my conception and subsequently refute it. Qualia are the things like “seeing a blue sky” or “experiencing jealous rage” which it is thought that people have in their minds when perceiving or partaking of such phenomena. They are the incommunicable “what it’s like” part of any perceptual experience.
To be fair, thinking that there are such physically intangible phenomena is probably a majority common sense view. If a man is born blind, how would you explain to him what it’s like to see? Indeed, doesn’t it seem plainly impossible that we could ever communicate such knowledge to him? The answer, of course, is no1. But even so, let’s take Frank Jackson’s example2: Fred. Fred has an unusual ability to distinguish between two different parts of the “red” segment of the light spectrum. He sees “red1” as distinct from “red2” just as he sees blue as distinct from yellow. These circumstances aren’t too far fetched and we can accept that Fred has a plausible ability.
Using Fred as an example, Jackson will try to present what he calls the Knowledge Argument for the existence of qualia. Jackson’s assumptions are very important because they deal with the very things his refutation involves, namely, physical things. He says he will call all physical data and things that come along with them “physical information” and then assumes that we know all “physical information” about Fred. We know Fred’s internal physiology, everything about his history and relations to others, the structure of his optical components, et cetera. Still then, Jackson claims, there is something we don’t know. We don’t know what it’s like to see red1 as distinct from red2. In fact, we will never know no matter how much we study Fred and his physical parts, the argument goes. Therefore we are to conclude that there are things left out about our knowledge of Fred even though we have all physical knowledge of him. Thus physicalism is false.
It is a valid argument and it might even be compelling. That is, if we were to overlook the fact that knowing “everything physical about Fred” is something we (as humans) currently do not have the power to do. This refutation is almost trivial for the common physicalist because most physicalists readily admit that we do not know everything there is to know about the physical world, especially matters involving the brain.
We could conceive of neural monitoring equipment sophisticated enough to isolate the brain activity while Fred perceives two different reds. We would then have physical evidence for his perception, but moreover if we had additional equipment, we could stimulate analogous areas of another person’s brain who had normal visual abilities. It seems entirely plausible that this person would then too see the difference between red1 and red2.
The problem with Jackson’s argument is that he assumes he has all physical knowledge about Fred and that he still doesn’t know the result of Fred distinguishing between two reds. This assumption is simply not compatible with physicalism and so can’t support the rest of his argument. Jackson even goes so far as to say that if someone else were to receive Fred’s optical equipment as a transplant, the new subject would then know what it’s like to distinguish between two reds. He does this with knowledge that Fred’s optical equipment is the reason that Fred can distinguish between two reds, but fails to recognize that the physicalist would say that the optical equipment merely causes changes in the brain that represent what the equipment perceives.
So it seems Jackson falls short for the physicalist with this argument, but I’ll examine his next argument, the Modal Argument, in a later article.
References
- Towards a Cortical Visual Neuroprosthesis for the Blind [pdf]
- Jackson, Frank. Epiphenomenal Qualia, from Mind and Cognition, Second Edition pp. 441-442, ed. Lycan. Blackwell Publishing, 1999.
You’re silly. ^_^
Knowing all physical information is a sufficient but not necessary condition for the argument. It is an “even if”, not a basic assumption. “Even if” we know all physical information, we do not understand what it is to feel. If we know less than all physical information, it’s even less likely we understand the feeling. If we don’t know all physical information, that does not negate the argument. This ain’t no contrapositive.
You also fall into a more obvious trap. When you say “something we (as humans) currently do not have the power to do”, you are discussing current technological sophistication, not theoretical limits. That has no place in Jackson’s argument which is, of course, about what we can theoretically know. His argument is unaffected by how much we know about brain anatomy at this moment. Consider: if it were true now, it would be true a hundred years ago.
It would not be enough to stimulate the appropriate areas of another person’s brain; the structure of the two brains would be fundamentally different in the visual cortex. The red1 and red2 areas would be one and the same in a normally-sighted person. The pathways would be intermingled, because there was never cause for them to dissociate.
On another note, a woman was found in Britain a couple of years back who has an extra set of optical receptors. She can, in fact, distinguish more colors than most people. She is to normally-sighted people as normally-sighted people are to colorblind people. She, effectively, is Fred.
Also, the knowledge argument is just as true from the angle that: a red-green colorblind person will never know what it is like to distinguish red from green. That makes it, to me, a lot more concrete.
Quite true.
Your assesment of Jackson’s presentation is accurate, but without this premise (whether he realizes it or not), his argument is dead in the water for begging the question. If this premise were not present, he would essentially be saying, “Let us define qualia as some non-physical mental phenomena. Therefore there is more to mental phenomena than what is physical. QED.”
One can’t define qualia as something non-physical when that’s the goal of the argument, so instead one must have some alternate way of showing qualia are non-physical. Jackson attempts to do this by assuming that he has all physical knowledge about Fred, but, as I already pointed out, if he actually had that knowledge, he would be able to represent the qualia as something physical. Of course this is physicalist speculation, but that doesn’t matter because the point of the argument is proving that qualia are not physical.
This is off the mark because it doesn’t matter what Jackson’s argument requires in this instance, but simply what my refutation requires. My refutation hinges on the fact that Jackson does not in fact know all physical information about Fred, for if he did, he would already have qualia as physically represented. Thus the point about what we (as humans) are currently incapable of is simply meant to illuminate the implausibility of Jackson’s first assumption, not to directly refute any claim of his own with regard to current or theoretical human capabilities.
This is pure speculation, but even as such it only helps prove my point. If Fred’s brain has a different structure because of his unique optical equipment (which is something I allow for), then there is a physical result of his condition. It is then still entirely conceivable that someone else (even, say, a baby for simplicity’s sake) could receive a transplant of Fred’s optical equipment and undergo the same brain changes. That person would eventually know what it’s like to see red1 and red2 as distinct from one another.
Realize also that I’m taking a functionalist perspective on the physical correlates of qualia. If there is some brain pattern or series of unrelated patterns in different people that achieve the same end, they represent the same qualia that I am after.
Again, it seems entirely plausible (and not disproved) that a red-green colorblind person could undergo some changes in his or her visual cortex and eventually be able to distinguish between red and green. Whether or not this would be done by direct stimulation of the brain or by a transplant of normal optical equipment followed by a long “training” period is irrelevant. The point is that the qualia could still be represented physically in the brain.
Thanks for your contribution! :)
Wow, very interesting article, Brad. I hope to see you as a new 9rules member, soon! Thanks for stopping by. :-)