Vision is the most vital step in the policy process. If we don’t know where we want to go, it makes little difference that we make great progress. Yet vision is not only missing almost entirely from policy discussions; it is missing from our whole culture. We talk about our fears, frustrations, and doubts endlessly, but we talk only rarely and with embarrassment about our dreams. Environmentalists have been especially ineffective in creating any shared vision of the world they are working toward — a sustainable world in which people live within nature in a way that meets human needs while not degrading natural systems. Hardly anyone can imagine that world, especially not as a world they’d actively like to live in. The process of building a responsible vision of a sustainable world is not a rational one. It comes from values, not logic. Envisioning is a skill that can be developed, like any other human skill. This paper indicates how.