Carol Brightman, who wrote a book on the novelist and critic Mary McCarthy, a traveler in rarefied literary circles, then wrote another on what might be considered McCarthy’s polar opposite , the Grateful Dead, died on Monday in Damariscotta, Maine . She was 80 .

Her daughter, Sarabinh Levy-Brightman , confirmed the death. She said Ms. Brightman had a number of health problems, including advanced dementia.

Early in her varied career Ms. Brightman was known for her involvement in the issues of the 1960s; among other things, she founded Viet Report , an influential newsletter about the Vietnam War, in 1965. She traveled to both North Vietnam and Cuba during that period, one of the few Americans to do so.

But she was perhaps best known for three books. In 1992 she published “Writing Dangerously: Mary McCarthy and Her World,” a biography of the groundbreaking, sometimes controversial author of “The Group” (1963) and other novels. Susan Brownmiller, reviewing “Writing Dangerously” in The Chicago Tribune, called it “a thoughtful, utterly admirable venture, written with the kind of balance and fairness that McCarthy herself was not wont to display.”