Qualia
The felt qualities of experience: the redness of red, the bitterness of coffee, the sting of pain — what no description seems to convey completely.
Definition
The word (singular: quale) was introduced in its modern sense by C. I. Lewis in 1929. The most famous thought experiment is Frank Jackson’s (1982): Mary, a scientist who knows everything about the physics of colour, has spent her whole life in a black-and-white room. The day she sees a tomato, does she learn something?
If so, there would be something in experience that escapes even a complete physical description. The argument has been debated for forty years. It takes on new relief with machines that can say everything about colours without, perhaps, ever having seen one.
See also
Related notions
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