The Future is Fiction is the first cultural history of the idea that people have an obligation to protect the world for future generations. While political philosophers have regarded intergenerational justice as an important field of study since the 1970s, the history of modern forms of obligation to the future has received almost no attention. This book traces the evolution of the Anglo-American concept of intergenerational justice, from its origins in eighteenth-century democratic revolutions to its flourishing in the 2000s. Thus, it illuminates the contours of a political conviction that has shaped modern culture. Margolis's central claim is twofold: first, that fiction's capacity to imagine counterfactual worlds has made the most significant contribution to contemporary understandings of intergenerational justice; and second, that this contribution has been misunderstood. Rather than inspiring political change, fiction demonstrates that complex societies will inevitably clash over what counts as a good future and what should be done to bring this future into being. From nineteenth-century utopian novels like James Fenimore Cooper's The Crater and Mary E. Bradley Lane's Mizora, to post-nuclear war dystopias, like Russell Hoban's Riddley Walker, and Walter Miller's A Canticle for Leibowitz, to recent fiction about endangered children like Toni Morrison's Paradise, Suzanne Collins's The Hunger Games, and Kazuo Ishiguru's Never Let Me Go, the tradition of future-oriented fiction recognizes that our obligation to the future is not the solution to an ethical problem, but an ethical dilemma in its own right.