Mary's room
Frank Jackson · "Epiphenomenal Qualia" · 1982
Mary is a brilliant vision scientist: shut all her life in a black-and-white room, she has nonetheless learned, on a monochrome screen, everything physical science can say about color. Every wavelength, every cell of the retina, every circuit of the brain: no part of the mechanism escapes her. One day she is let out, and for the first time she sees a red rose. Does she then learn something? If she does, then a complete knowledge of the still left a remainder: what it is, for a living being, to see red.
On seeing red for the first time, does Mary learn something that science had not given her?
What it does in the debate
Objects to Scientismattacks the position
Mary knows all the physical facts about color without having seen it; on seeing red, she learns something. A complete physical knowledge thus left a remainder: science does not exhaust the real.
- Mary knows everything physical science says about color, but has never seen anything except in black and white.
- The day she comes out and sees a red rose, she learns something new: what it is to see red, which no textbook contained.
- There are, then, truths that a complete physical knowledge let slip: the real overflows what science, however accomplished, can put into statements.
Therefore So science does not exhaust the real: against scientism, lived first-person experience gives an access of its own, irreducible to objective knowledge.
Objects to Physicalismattacks the position
Mary knows all the physics of colour and yet learns something on seeing red: experience was therefore not contained in the complete description of the brain.
- Mary knows every physical fact about colour vision, down to the last cerebral circuit, without ever having seen anything but black and white.
- On coming out, she sees a red rose and learns what it is to see red: something she did not know, and that no further physical information would have given her.
- If experience were identical with the cerebral state, she would have nothing to learn: she already possessed, in principle, the complete description of that state.
Therefore So experience is not exhausted by the brain's workings: a fact remains that the complete physical description did not contain.