Introduction Daniel Stoljar and Yujin Nagasawa

Mary is confined to a black-and-white room, is educated through black-and-white books and through lectures relayed on black-and white television. In this way she learns everything there is to know about the physical nature of the world. She knows all the physical facts about us and our environment, in a wide sense of 'physical' which includes everything in completed physics, chemistry, and neurophysiology, and all there is to know about the causal and relational facts consequent upon all this, including of course functional roles. If physicalism is true, she knows all there is to know. For to suppose otherwise is to suppose that there is more to know than every physical fact, and that is just what physicalism denies. ... It seems, however, that Mary does not know all there is to know. For when she is let out of the black-andwhite room or given a color television, she will learn what it is like to see something red, say. This is rightly described as learning—she will not say “ho, hum.” Hence, physicalism is false. (Jackson 1986, p. 291, Chapter 2, this volume)