Diane Arbus’s photographs were already famous to people who follow photography when she killed herself in 1971; but, as with Sylvia Plath, the attention her work has attracted since her death is of another order—a kind of apotheosis. The fact of her suicide seems to guarantee that her work is sincere, not voyeuristic, that it is compassionate, not cold. Her suicide also seems to make the photographs more devastating, as if it proved the photographs to have been dangerous to her.

— Susan Sontag, On Photography, 1977