What will the future be like? Our inability to answer this question with certainty has never stopped us from wondering and guessing, both about our personal futures and the future of the world. During the past century, the speculations about the latter have grown more numerous, diverse and elaborate than ever. Stories set in some projected time after our own have created such powerful images of the future that they shape our culture in the present, for better or worse. Although no expert on futuristic stories, I find the ideas underlying them intriguing and sometimes troubling. What do our imaginings do for us—or to us—now?