Incomplete Nature begins by accepting what other theories try to deny: that, although mental contents do indeed lack the physical properties that are assumed to be necessary for something to have physical consequences in the world, they are still entirely products of physical processes. And they have an unprecedented kind of causal power that is intrinsically incomplete and therefore unlike anything that physics and chemistry alone have so far explained. The book’s radically challenging conclusion is that we are made of these specific absences—such stuff as dreams are made on—and that what is not immediately present can be as physically potent as that which is. It offers a figure/background shift that shows how even meanings and values can be understood as legitimate components of the physical world.