Susan Sontag came of age during the late 1940s and early 1950s, as the United States was exploding into a new era of prosperity, artistic and cultural transformation, urban development and suburban growth, political upheaval, and the beginnings of the modern civil rights movement. After emerging victorious from World War II, the U.S. had become a major superpower, as well as the world’s police officer. It quickly moved into the Cold War with the Soviet Union: an arms race and fierce ideological battle. It was a period of hope and transformation, but also of bullying and deception: at home, McCarthyites spread fear through communist- and gay-baiting “witch hunts.” The 1950s were the height of what Henry Luce of TIME deemed “The American Century.”

Then the ‘60s arrived. The jazz was cool, the world felt young again, and New York was the place to be. At thirty-one, Sontag entered the New York literary and intellectual world and changed all the rules, becoming an instant star. Her image graced the covers of magazines. She posed in Ray-Bans for Andy Warhol. Like Bob Dylan, she defined her times, ushering in a new vogue. In the electrifying years between 1960 and 1966, she defined intellectual chic and transformed what could be taken seriously in the world of art and ideas

Susan Sontag was born in New York City in 1933, and raised in Arizona and Los Angeles. A precocious, bookish child, she graduated high school at fifteen, attending the University of California, Berkeley, briefly, and then the University of Chicago. Sontag was 17 when she met sociologist Philip Rieff and quickly married him; their son, David, was born two years later. She received a master’s degree in philosophy from Harvard, and continued her studies at Oxford and the Sorbonne. But after teaching briefly at Columbia University, Sontag left academia and captivated the New York literary scene with an ambitious first novel, The Benefactor, and a series of essays for Partisan Review. She wrote radically about low culture from a position within high culture, in an effort to expand what could be taken seriously in the arts. Later, she made waves with On Photography, presciently outlining the art form’s central role in modern consumer culture, and calling for an “ecology” of images. After surviving a terminal breast cancer diagnosis and a mastectomy at the age of forty, Sontag turned to the subject of illness, becoming a role model to many who struggle with disease.

Sontag did not shrink from political controversy, confounding her literary colleagues with political stands that changed radically over time. Yet even her detractors—who called her inconsistent and elitist—acknowledged her bravery. She was vehemently opposed to the Vietnam War, and famously visited Hanoi in 1968, in the midst of heavy American bombing, notoriously proclaiming, “the white race is the cancer of human history.” Sontag continued bearing witness to war and violence throughout her life. Decades later, her brief comments in The New Yorker in the aftermath of 9/11, about the underlying causes of the tragedy, unleashed a firestorm of anger. For her willingness to criticize American foreign policy, she was labeled a traitor. Her last book, Regarding the Pain of Others, examines our responses to images of war and torture.

Sontag embodied an ideal, a zenith that none could equal but many aspired to: the possibility of a committed life, an intellectual life, and a life of thinking and writing outside of the academy. She was the foremost female intellectual of her day, and refused to be reduced to her gender, but was also perfectly willing to use her beauty and sensuality to advance her career. Publicly, she was the fierce “dragon lady” of American letters; in private, she was as confused and vulnerable as the next person. Since girlhood, Sontag had been pushing socially acceptable boundaries to make room for herself as a brilliant woman in a circle of men, yet she was unwilling to reveal her vulnerabilities, for fear of being dismissed as weak. She kept her sexuality private, assuming it would be used against her. Before her death, she hesitatingly admitted to being bisexual, though her diaries are much more explicit. “My desire to write is connected to my homosexuality,” she confided in a 1959 journal entry. “I need the identity as a weapon to match the weapon that society has against me. I am just becoming aware of how guilty I fear being queer.”

Susan Sontag died on December 28, 2004, of acute myelogenous leukemia, after an intense struggle with the disease, her third form of cancer. Although her eloquent voice has been silenced, she lives on in her books, essays, letters, and in the dramatic interviews and footage she left behind.