In this thought experiment, known as Mary's room, he asks us to consider a neuroscientist, Mary, who was born, and has lived all of her life, in a black and white room with a black and white television and computer monitor where she collects all the scientific data she possibly can on the nature of colours.
Oma mõtteeksperimendis (nn Mary tuba) räägib ta neuroteadlasest Maryst, kes on sündinud ja kogu elu elanud mustvalges toas, kus on mustvalge televiisor ja mustvalge arvutiekraan, ning on seal kogunud kõik andmed värvuste loomuse kohta, mis tal oli võimalik saada.