Wednesday, November 17, 2010

Science and the Color Red

One of the problems physicalists have to deal with is how what are called qualia can be physical. (Qualia are mental states that involve sensations, or "raw feels," like the feeling of pain, an itch, or nausea, or the experience of redness.) The worry for physicalism is that it is unclear how physicalism can account for qualia. How can the feel of pain simply be a state of the brain or an event going on in it (the organization or firing of neurons, for example)?

An argument called "The Knowledge Argument" was put forward by philosopher Frank Jackson years ago, and it claims that qualia cannot be physical. The basic idea: Mary, a brilliant neuroscientist, knows everything physical that goes on in a person's brain when a person sees something red. However, Mary herself has been locked her whole life in a black-and-white room and prevented from seeing anything red herself. Now suppose she is released and allowed for the first time to see a red tomato. At this point, so the argument goes, she learns something new. She knew all the physical facts about color-vision, but she didn't know all the facts about color vision--she didn't know what red looks like! Hence some of the facts about color-vision aren't physical, and hence physicalism is false.

This argument has been much debated, but despite increasing advances in cognitive neuroscience, the question of how physicalism can account for qualia, or for consciousness more generally, will not go away. It is raised again, nicely, in the Toronto Globe and Mail, in an article "Science still can't explain the colour red," which quotes some top contemporary philosophers and cognitive scientists who have done work on the subject.

Speaking of philosophers and cognitive scientists, here at Bethel our very own Dan Yim is co-teaching a course on consciousness this spring with a member of the psychology department. The course is called "Consciousness: Psychology and Philosophy in Dialogue." No doubt it will discuss the question raised in the Globe and Mail article: how much can science tell us about the mind?


Cartesian said...

The case of colour-blind persons is very interesting.

Ray said...

Yes, it is. (I perceive the apple to be red, the color-blind person perceives it to be gray: what color is the apple, REALLY?) Even color-blind people, however, are having qualitative experiences--qualia--that are difficult for physicalists to account for. Science has the same problem with the color gray as with the color red.