Mary’s Room
Mary’s Room
Also known as: The Knowledge Argument
Description
Mary’s Room is a thought experiment by philosopher Frank Jackson (1982) to challenge physicalism—the belief that all knowledge is physical knowledge. Mary is a brilliant scientist who knows everything about the science of colour (wavelengths, optics, neurology) but has lived her entire life in a black-and-white room and has never seen colour herself.
Key Question
When Mary sees the colour red for the first time, does she learn something new?
Purpose
To argue that there are non-physical aspects of knowledge—specifically qualia (subjective experiences). If Mary learns something new (what red looks like), then not all knowledge is physical, suggesting that consciousness involves more than physical facts (see the Hard problem of consciousness).
Notes:
- I believe that Mary learns something, but not about the colour red; she learns how her eyes and brain react to the presence of the wavelengths of light in response to the colour red. She learns about her subjective experience, first-person knowledge of her own perceptual response. This is new information about her brain, not about redness, and it is entirely physical.
- If shown two colours upon leaving the room, Mary would not, a priori, know which if any was the colour red.
- Jackson himself later abandoned the argument and accepted physicalism.
Source
Jackson, F. (1982). Epiphenomenal Qualia, Philosophical Quarterly.