The cause was lung cancer, said her husband, Stanley Aronowitz, the well-known sociologist and progressive activist.
At her death, Ms. Willis was a professor of journalism at New York University. She also directed the journalism department's cultural reporting and criticism program, which she founded in 1995.
As a writer, she was best known for her political essays, which appeared in The Nation, Dissent and elsewhere. She was also widely recognized for her rock criticism: she was the first pop-music critic of The New Yorker, and wrote regularly about music for Rolling Stone, The Village Voice and other publications.
In addition, Ms. Willis was a vital figure in the women's movement of the late 1960s and afterward. She was a founder of Redstockings, a short-lived but highly influential radical feminist group begun in 1969. In the 1980s, she helped found No More Nice Girls, a street theater and protest group that focused on abortion rights.
At its core, Ms. Willis's work was rooted in the three R's, which for her were radicalism, religion and rock. But little escaped her scrutiny, and over the years, her writings embraced subjects as diverse as psychoanalysis, the O. J. Simpson trial, Monica Lewinsky and "The Sopranos." To Ms. Willis, each of these was a strand in the contemporary social fabric, and her responsibility as critic was to map out the complex ways in which they interlaced.
In an essay in The New York Times in 1999, Ms. Willis wrote:
"The Lewinsky scandal has prompted an impassioned national conversation on the relationship of the political to the personal, public authority to private behavior; on sexual privacy versus 'family values'; on female sexual autonomy and victimization. Granted, the affair has also produced an outpouring of schlock with no redeeming social value. But far from vindicating the eat-your-vegetables school of journalism, the schlock suggests what's wrong with it. Arguably, just as Victorian repression produced a thriving pornography industry, the exclusion of sex from 'serious ' news media produced tabloidism. As this taboo passes into history, there should be more room for a public conversation on sex that is neither coy nor prurient, but simply frank."
Though Ms. Willis liked to describe herself as an anti-authoritarian democratic socialist, she was leery of extremism of either stripe. An outspoken advocate of women's sexual empowerment, she also publicly condemned feminists who wanted to ban pornography. (She was disturbed by what she viewed as their Puritanism, and by the threat to free expression.) She also took some members of the American left to task for what she saw as anti-Semitism thinly veiled as political animus toward Israel.
"My education was dominated by modernist thinkers and artists who taught me that the supreme imperative was courage to face the awful truth, to scorn the soft-minded optimism of religious and secular romantics as well as the corrupt optimism of governments, advertisers, and mechanistic or manipulative revolutionaries," Ms. Willis wrote in an essay collected in "Beginning to See the Light: Pieces of a Decade" (Knopf, 1981). She continued:
"Yet the modernists' once-subversive refusal to be gulled or lulled has long since degenerated into a ritual despair at least as corrupt, soft-minded, and cowardly - not to say smug - as the false cheer it replaced. The terms of the dialectic have reversed: now the subversive task is to affirm an authentic post-modernist optimism that gives full weight to existent horror and possible (or probable) apocalyptic disaster, yet insists - credibly - that we can, well, overcome. The catch is that you have to be an optimist (an American?) in the first place not to dismiss such a project as insane."
Ellen Jane Willis was born in Manhattan on Dec. 14, 1941; her father was a lieutenant in the New York Police Department. Reared in the Bronx and Queens, she earned a bachelor's degree in English from Barnard in 1962 and afterward did graduate work in comparative literature at the University of California, Berkeley.
Ms. Willis was divorced after an early marriage. She wed Mr. Aronowitz, her longtime companion, in 1998. She is survived by Mr. Aronowitz, a distinguished professor of sociology at the City University of New York and the Green Party candidate for governor of New York in 2002; their daughter, Nona Willis-Aronowitz, of Manhattan; two siblings, Michael Willis of Johannesburg, South Africa, and Penny Willis of Queens; four stepchildren, Michael O'Connell of Basking Ridge, N.J.; Kim O'Connell of Montclair, N.J.; Alice Finer and Hampton Finer, both of Brooklyn; and two step-grandchildren.
Ms. Willis's other books include "No More Nice Girls: Countercultural
Essays" (University Press of New England, 1992); and "Don't Think, Smile! Notes on a Decade of Denial" (Beacon Press, 1999).
Despite her anti-authoritarian positions - or perhaps because of them - she confessed to being constitutionally hopeful, however unfashionable that might seem. In the essay from "Beginning to See the Light" she described the condition this way:
"My deepest impulses are optimistic, an attitude that seems to me as spiritually necessary and proper as it is intellectually suspect."