Frank Jackson’s (1986) Mary is confined in a room in which the visual stimuli are all grayscale, so that her visual experiences have all been achromatic. Nonetheless, from books and television lectures, she has gotten all factual knowledge one can get from any source that pertains to the having of conscious visual experiences. It could indeed be “everything [factual] there is to know about the physical nature of the world,” based on “completed” science. But, Jackson writes, “[i]t seems … that Mary does not know all there is to know. For when she is let out of the black-and-white room or given a color television, she will learn what it is like to see something red, say” (1986, 291; emphasis Jackson’s).