Robert A. Heinlein began publishing in the 1940s at the dawn of the Golden Age of science fiction, and today he is considered one of the genre's 'big three' alongside Arthur C. Clarke and Isaac Asimov. His short stories were instrumental in developing its structure and rhetoric, while novels such as Stranger in a Strange Land and Starship Troopers demonstrated that such writing could be a vehicle for political argument. Heinlein's influence remains strong, but his legacy is fiercely contested. His vision of the future was sometimes radical, sometimes deeply conservative, and arguments have flared up recently about which faction has the most significant claim on his ideas. In this major critical study, Hugo Award-winner Farah Mendlesohn carries out a close reading of Heinlein's work, including unpublished stories, essays, and speeches. It sets out not to interpret a single book, but to think through the arguments Heinlein made over a lifetime about the nature of science fiction, about American politics, and about himself.