Excerpted from Dan Berrett:

“Occupy Wall Street’s most defining characteristics—its decentralized nature and its intensive process of participatory, consensus-based decision-making—are rooted in other precincts of academe and activism: in the scholarship of anarchism and, specifically, in an ethnography of central Madagascar.

It was on this island nation off the coast of Africa that David Graeber, one of the movement’s early organizers, who has been called one of its main intellectual sources, spent 20 months between 1989 and 1991. He studied the people of Betafo, a community of descendants of nobles and of slaves, for his 2007 book, Lost People.

Betafo was “a place where the state picked up stakes and left,” says Mr. Graeber, an ethnographer, anarchist, and reader in anthropology at the University of London’s Goldsmiths campus.

In Betafo he observed what he called “consensus decision-making,” where residents made choices in a direct, decentralized way, not through the apparatus of the state. “Basically, people were managing their own affairs autonomously,” he says.

The process is what scholars of anarchism call “direct action.” For example, instead of petitioning the government to build a well, members of a community might simply build it themselves. It is an example of anarchism’s philosophy, or what Mr. Graeber describes as “democracy without a government.”

He transplanted the lessons he learned in Madagascar to the globalism protests in the late 1990s in which he participated, and which some scholars say are the clearest antecedent, in spirit, to Occupy Wall Street.

Soon after the magazine Adbusters published an appeal to set up a “peaceful barricade” on Wall Street, Mr. Graeber spent six weeks in New York helping to plan the demonstrations before an initial march by protesters on September 17, which culminated in the occupation.

It is far from clear, of course, how attuned the protesters are to the scholarship of Mr. Graeber, other critical theorists, or academics who study anarchism. A growing collection of fiction and nonfiction books, however, has a post-office box to which supporters are invited to send books. “The People’s Library” in New York City, which has been copied at other Occupy protest sites, houses nearly 1,200 books in cardboard boxes that are protected against the elements by clear plastic sheeting.

“I really am amazed for the respect they have for the word,” Eric Seligson, the librarian at the protest site on Wall Street, told Esquire. “There’s a real reverence for what has been written that has surprised me, since they eschew whatever came before, all the thought that came before.”

The defining aspect of Occupy Wall Street, its emphasis on direct action and leaderless, consensus-based decision-making, is most clearly embodied by its General Assembly, in which participants in the protest make group decisions both large and small, like adopting principles of solidarity and deciding how best to stay warm at night.

This intensive and egalitarian process is important both procedurally and substantively, Mr. Graeber says. “One of the things that revolutionaries have learned over the course of the 20th century is that the idea of the ends justifying the means is deeply problematic,” he says. “You can’t create a just society through violence, or freedom through a tight revolutionary cadre. You can’t establish a big state and hope it will go away. The means and ends have to be the same.”

When 2,000 people make a decision jointly, it is an example of direct action, or direct democracy, Mr. Graeber says. “It makes you feel different to go to a meeting where your opinions are really respected.” Or, as an editorial in the protest’s house publication, Occupied Wall Street Journal, put it, “This occupation is first about participation.”

Three days after the protests began, Mr. Graeber left. Since then, he has kept a low profile because he wants to avoid what he calls an “intellectual vanguard model” of leadership. “We don’t want to create a leadership structure,” he says. “The fact I was being promoted as a celebrity is a danger. It’s the kids who made this happen.”