Early in the twentieth century a new character type emerged in the crime novels of American writers such as Dashiell Hammett and Raymond Chandler: the "hard-boiled" detective, most famously exemplified by Sam Spade in The Maltese Falcon. Unlike the analytical detectives of nineteenth-century fiction, such as Edgar Allan Poe's Dupin, the new detectives encountered cases not as intricate logical puzzles but as stark challenges to manhood. In the stories of these characters and their criminal opposites, John T. Irwin explores the tension within ideas of American masculinity between subordination and independence and, for the man who becomes "his own boss," the conflict between professional codes and personal desires.