Susan Sontag was born Susan Rosenblatt in New York City. Her businessman father died in China when she was only five, and her mother moved the family to Arizona, where she hoped the climate would alleviate her daughter’s asthma. Sontag and her sister Judith spent their early years in Tucson, where they were educated in the public schools. Already evincing signs of her formidable intellect, Sontag began school in the third grade.

She drew on memories of her early years in her short-story collection, I, Etcetera (1978), where she mourns the loss of her father and describes herself in her Tucson backyard trying to dig a hole to China. In “Project for a Trip to China,” included in this volume, she imagines going to the land where her father died—a trip she later took after she wrote this autobiographical story, which reveals how as a young girl she tried to fill the emptiness and loneliness of her childhood through reading and an intense imagination. Sontag felt the need to draw deeply on her own resources because of what she described as an aloof and alcoholic mother.

Sontag’s mother remarried Nathan Sontag when her daughter was twelve, and both Susan and Judith were given their stepfather’s last name. The family moved to Canoga Park, California, where Sontag attended North Hollywood High School. A brilliant student who wrote for the student newspaper and was already developing an avid taste for music, art, and literature, Sontag was easily bored—as she recounts in her autobiographical essay “Pilgrimage,” published in The New Yorker on December 21, 1987.

The precocious Sontag graduated from high school at the age of fifteen and spent a semester at the University of California, Berkeley, a compromise choice because her mother feared her daughter was too young to attend the University of Chicago, her daughter’s first choice because of its radical reputation.

However, after only one semester, Sontag departed for Chicago, attracted to its intense intellectual atmosphere and the chance not only to enroll in philosophy and literature classes but also to audit as many other classes as she liked—including one in psychology taught by a brilliant sociology instructor, Philip Rieff, whom she married at the age of seventeen. Their intense relationship and their efforts to educate their son David are explored in “Baby,” a story in I, Etcetera.

Sontag worked with her husband on a ground-breaking book, Freud: The Mind of a Moralist (1959), but her role in this important study was acknowledged only in the first edition and then omitted in subsequent printings of the book following the couple’s divorce—a painful episode that Sontag alludes to in “Zero,” the prelude to her novel In America (2000).

After receiving a master’s degree in philosophy from Harvard and teaching at several colleges and universities, including Columbia University and Sarah Lawrence College, Sontag embarked on a career as a freelance novelist and critic. Her first two novels, The Benefactor (1963) and Death Kit (1967), received respectable but mixed reviews. To many critics, this work seemed to slavishly imitate the French “new novel” pioneered by writers such as Natalie Sarraute and Alain Robbe-Grillet. Sontag’s fiction tended toward the surrealistic, and her literary criticism rejected the social and psychological realism of contemporary American novelists.

Sontag made her reputation as a public intellectual with two collections of criticism, Against Interpretation, and Other Essays (1966) and Styles of Radical Will (1969). These two works summed up her aesthetic and political positions as an ardent advocate of avant-garde art and as an adversary of U.S. foreign policy in Vietnam, South America, and developing countries, where the...