In conversation, then, Hardt comes across less as a relentless firebrand than an engaging idealist. Still, he has had to fend off accusations against his co-author, Antonio Negri. The National Review calls Negri "the brains behind the Red Brigades," the Italian terrorist group that operated in the Seventies. A similarly hostile New Republic declares that "the question of whether Negri was himself a violence-prone terrorist is still open." The evidence makes it a closed question, according to Hardt. He says that Autonomia Operaia, the leftist group with which Negri was associated, was not a terrorist organization. "It was a political group that did some violent things, but it wasn't a terrorist group by any consideration. He's never been charged with nor convicted of any acts associated with terrorism. He's been charged with and convicted of being responsible for acts of political violence. And he's been held responsible for them not on the basis that his writings led to the acts--not owing to his having knowledge of or participation in the acts--but because his writings identified him as a leader of a group."

Hardt says he thinks it's important to be accurate about "the political past," but also to separate it from a contemporary context. "Both in legal terms and in terms of general moral responsibility, his writings supported acts of political violence. That's true. One could think that Negri, in the years since the 1970s, has changed his thinking about such things. Or one could think that the times have changed, and that he views these times differently than he views the past. At least in my mind, our book doesn't promote or condone or even deal with the question of political violence except in the broad sense, in terms of state violence."

He doesn't feel an obligation to crusade on behalf of Negri (now serving a loose form of house arrest in Rome), Hardt says. But he adds that it's satisfying to see his co-author, through the success of the book, being "transformed from an old political leader from the Seventies to an international philosopher."

It was along a zig-zaggy intellectual path that Hardt found Negri as an intellectual collaborator. Hardt grew up outside Washington, D.C.; his father was a Sovietologist specializing in economics at the Library of Congress. At Swarthmore College in Pennsylvania, he studied engineering. This was the late Seventies, when the nation was in the midst of its energy crisis, and Hardt was drawn to alternative energy sources. During vacations, he worked at a factory in Italy making solar panels. "Not only exploring alternative forms of energy, but also bringing technology to different parts of the world seemed like a form of political activity to me," he says. "Then I recognized the limitations of technology; I was working as an engineer and it no longer seemed rewarding to me, partly in a political sense."

Hardt moved to Seattle in 1983, and he later earned a Ph.D. in comparative literature from the University of Washington. In the same period, he worked in Guatemala and El Salvador for the Christian Sanctuary Movement, which gave church shelter in the U.S. to refugees from the "dirty wars" in Central America. "I remember having El Salvadorans telling me, 'it's very nice that you're here, but you should go home and make a revolution at home.' That seemed utterly impossible at the time. But I learned a lot from them. Most importantly they taught me that the process of politics itself is a collective, a joyful activity."

As an academic generalist in a market that values specialization, Hardt found the process of landing a job less than joyful. He applied to French, Italian, English, political science, and philosophy departments. Finally, in 1993, he took a job in the Italian department at the University of Southern California in Los Angeles, and quickly found himself at some intellectual remove from his colleagues. "I went to a conference on Marx and deconstruction," he told The New York Times. "I listened to a series of papers that were so convoluted and abstract. The speakers said they were talking about politics, but I couldn't understand a thing political about them. I was so frustrated after the weekend that on the Monday after, I called the state prison commission and found out how I could volunteer teaching at the local prison."

In 1994, he moved to Duke's literature program as an assistant professor. He says he felt from the start that he had found an intellectual home, that Duke in general and the program in particular "recognize the importance of interdisciplinary studies." Typically, he says, interdisciplinary scholars establish themselves in a particular discipline before they feel comfortable branching out. "I remember thinking when I first came to Duke that I hoped that I could get job where I'd be tolerated. I didn't expect to get one where I'd actually be appreciated."

By that time, he was already collaborating with Negri on Empire. (He says this is a pure kind of co-authorship: "The book is not written in my voice, it's not written in his voice. It's as if there were a third voice that we've adopted for the project. I try to write what he might say, he tries to write what I might say, but we end up talking in a language that's neither mine nor his.") In the mid-Eighties, Hardt had asked a friend to introduce them during a visit to Paris, where Negri had fled to avoid serving his jail sentence. "It seemed to me that he'd found a way to bring together his political interests and his scholarly interests," Hardt says of his collaborator. "I had felt that I had political interests on the one hand and then scholarly interests on the other. They never had anything to do with one another. Even the prospect of combining them seemed completely false."

Some scholars praise Empire for its power of synthesis; they say the book provides a needed spark, even a grand unified theory, to humanities fields like English, history, and philosophy. The writers don't just outline a new political system and new power relationships. They also offer a remarkably sweeping intellectual history, stretching from imperial Rome to Haitian slave revolts, and an equally remarkable range of thinkers, from Machiavelli to Foucault. And Hardt is a quiet proselytizer for the breaking down of barriers between disciplines. "I'd be pleased if we moved toward a more interdisciplinary paradigm. Certainly globalization and questions of empire engage with questions in the humanities and in the social sciences quite directly and quite broadly."

Thoroughly affable in manner, unfailingly graduate-student casual in dress, Hardt, the academic star illuminating this new Empire, is in many ways a traditional academic. He certainly doesn't see himself as a revolutionary. Despite the exuberant prose of his publisher, he resists calling the book a manifesto or a call to arms. The book is essentially "an analysis of the contemporary global situation rather than a proposition for its transformation," he says. It is geared to scholars and students, he says, not to the restless masses.

In the final passage of Empire, he and Negri write about communism, cooperation, and revolution. They also make references to "love," "simplicity," and "innocence," in the context of the teachings of Saint Francis of Assisi. "Francis in opposition to nascent capitalism refused every instrumental discipline, and in opposition to the mortification of the flesh...he posed a joyous life, including all of being and nature, the animals, sister moon, brother sun, the birds of the field, the poor and exploited humans, together against the will of power and corruption."

So that's the end point in this phase of Michael Hardt's political journey: not a looking forward to a utopian vision, but a looking backward to the quiet dignity of an individual.