 The possibility of madmen pushes us away from a simple functional definition of pain. Some creatures have pains that do not play the pain role. The possibility of Martians pushes us away from a purely neural definition of pains. Some creatures have pains that are not like our neural pain states. Indeed, some of them might have pains without having any neural states at all. Lewis’s way of threading this needle is to say that pains, like all mental states, are defined for kinds of creatures. Pains in humans are certain neural states. They are the neural states that (typically, in humans) have the functional role that we associate with pain. In other kinds of creatures pains are other states that (typically, in those creatures) play the pain role. The details of these views are worked out in “Mad Pain and Martian Pain” (1980c).