Saturday, July 11, 2009

against the knowledge argument

the knowledge argument is this (taken from Parableman)

Consider a color scientist named Mary who has never seen red. She lived in a black and white environment with special contact lenses all her life, so she'd never seen most colors. Then she went on to learn the neuroscience of color perception. She now knows everything there is to know from science about color perception. She knows what color words apply to which wavelengths of light. She knows what goes on in the brain when people see various colors. But she's never seen red. Then she takes off the contact lenses, and someone gives her a tomato. She now sees red for the first time. Does she learn something? Jackson says she does - what it's like to perceive the color red.

  1. Mary knows every physical fact about color perception.
  2. There's a fact about color perception that Mary learns when she sees red - namely, what it is like to experience seeing that color.
  3. Therefore, there are more than just physical facts (so materialism is false).
I suggest the main intuition tweeked by the mary argument is that mary does not have the brain power to know everything there is to know about experiencing red and to process it at a speed that would give the same feeling as seeing red and that even if she did this activity would occur in a logical part of her brain rather than a visual one so to mary as a whole it would seem different.

Because everyone has these limitations it is hard to imagine mary not having these limitations. But the existance of such limits dont threaten physicalism.

Or more simply we seem very far from being able to imagine "all the physical facts about colour perception". Because we are so far from doing this it seems unclear why we should expect our intuition (sense of implausibility) to be accurate regarding what isn't part of that set.


Anonymous Anonymous said...

This is not the point of Jackson's argument. The main point is that she does not know what it would be like to have an experience of, say, red is, even though, she has all of the physical information that specifies how vision functions. Once she steps outside and actually has the experience, then she learns something new, viz. what it is like to have an experience of the color red. It's also important to recognize that Jackson specifically mentions that the knowledge Mary gains is knowledge concerning how other people experience colors, not just her own experience of them.

2:53 PM  
Anonymous Anonymous said...

I tend to see the Knowledge Argument in terms of the difference between descriptive knowledge such as an equation or the text in your article and conscious experience. As it says in the following link, if descriptive knowledge were the same as the things that are described then by writing e=mc^2 I would vaporize myself! (see Superscientist Mary and types of physicalism.

1:50 AM  
Blogger Genius said...

Anon1 - that might be the point but is that the intuition being tweaked?

ahh I like that example!

10:35 PM  

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