Take the famous thought experiment of Mary, a neuroscientist trapped in a black-and-white room. She has learned every physical and mathematical fact about the color red — specific wavelengths, codes for different shades, rules for mixing other colors to create red, and so forth — but has never seen the color red herself. If she steps outside one day and sees red, the question is: does she learn something new? This experiment (the “knowledge argument”) was originally devised by philosopher Frank Jackson in 1982 as an argument against physicalism — the intuition being that Mary does learn something new, which would imply that physical facts alone don’t capture everything about conscious experience. Intuitively, most of us are inclined to answer “yes”, because we give importance to our subjective experiences.