Carl Sagan wrote The Demon-Haunted World at the end of his life, completing it roughly a year before he died of cancer. The book exemplifies well one of his major roles—being a communicator and promoter of science and skeptical thinking to lay audiences. As he makes clear in the preface, Sagan considers the course of his life shaped by his teachers, so the task of instructing others is of extreme importance to him. After achieving his PhD, Sagan worked as a professor of astronomy, first at Harvard, and then Cornell, where he taught until his death.

Outside of his academic research, Sagan wrote many popular science books, beginning with The Dragons of Eden (1977), a cross-disciplinary examination of the evolution of human intelligence that won him the Pulitzer Prize. Because of the book’s success, Sagan was asked to write and present a 13-part PBS special, Cosmos: A Personal Voyage, in 1980. The show was a huge hit, becoming the most widely watched public television series in the history of American television; it made Sagan a household name. His famous line from Cosmos—“Extraordinary claims require extraordinary evidence”—now known as the Sagan standard, encapsulates the argument he makes in The Demon-Haunted World.