Is it possible to imagine an alternative to capitalism? Private enterprise, the free market, cutthroat competition and the survival of the fittest; vast and highly diversified transnational corporations; shopping as a form of sexual satisfaction; shady financial transactions zapping across the globe in fractions of a second; mortgages, student loans, and credit cards that can never be paid off; the proliferation of brand names, corporate logos, and celebrity endorsements; gated communities and suburban McMansions on the one hand, and immense shantytowns and slums on the other: These are the contours of the world we live in. Postmodern capitalism is the very air we breathe; it's the background for every voyage, the setting for every story.

Of course, we know that things could fall apart at any moment. In this age of globalization and genetic engineering, the prospect of catastrophe is never far away. Our heads are filled with doomsday scenarios: terrorist attacks, radical climate change, a pandemic of avian flu or airborne AIDS, even collision with an asteroid. In the wake of 9/11 and Katrina, it's hard not to think that our culture is doomed. As the Slovenian philosopher Slavoj Zizek puts it, we find it easier to imagine the end of the world than the end of capitalism. We are scarcely able to envision a tolerable and pleasant world without money, advertising, and brand names, and without the vast inequities that characterize a competitive economy. We are missing what Fredric Jameson terms "the desire called utopia."

Jameson is America's leading Marxist literary critic. He's had a huge influence on American academia, spearheading the movement to consider things like "theory" and "postmodernism." In his own work, Jameson is a polymath who has more texts at his fingertips—everything from Hegel's Science of Logic to the collected works of Robert Heinlein—than I could even hope to skim in a lifetime. He combines close attention to the most abstruse matters of literary form with an acute awareness of literature's many external contexts: social, political, and economic.

In his new book, Archaeologies of the Future, Jameson takes on the genre of utopian fiction. He analyzes a wide range of texts, from Thomas More's Utopia of 1515, which gave its name to the genre, up to science fiction novels of the past few decades by the likes of Philip K. Dick, Ursula Le Guin, and Kim Stanley Robinson.

In dissecting these texts, Jameson also examines the broader topic of utopian longing: the desire for a better world. It's the urge to imagine a society free from the defects of the one we actually live in; and the drive to begin constructing such a society, not in the afterlife or in the distant future, but right here and right now.

The "desire called utopia" has been defeated again and again in our cruel and bloody history; there are many who would tell us just to forget about it, because human beings cannot achieve perfection. But utopianism springs up afresh after every defeat; eliminating the desire for a better world is finally just as ridiculous and impossible as eliminating sexuality, or irony, or the quest for intoxication. As long as there are jails, prisoners will dream of escaping them; and some will even try to put their dreams into action.

"Utopia" literally means "nowhere." Today, the utopian imagination finds its strongest expression in science fiction (SF). SF novels are thought experiments, exercises in "what if." They don't really claim to predict the future. Rather, they are about potentiality. They explore vectors of change, possibilities of difference. SF worlds are meaningful precisely because of their distance from present-day experience. They displace the known into the unknown, taking things that we recognize and putting them into forms and situations that we don't.

In the pages of Archaeologies of the Future, Jameson works his way through the projects and paradoxes of utopian SF. What he finds most crucial in utopian fiction is not its blueprints of a future existence, but rather its negation of the way things are now: Utopian SF posits "the future as disruption." In science fiction we traverse great stretches of space and time; we encounter alien beings, as well as conditions that are radically alien to our sensibilities. In these ways, SF shows us the contingency and changeability of even those things—like money and markets and multinational corporations—that we most take for granted.

Steven Shaviro is the DeRoy Professor of English at Wayne State University. He is the author of Connected, or What It Means to Live in the Network Society.