University of Minnesota

Sherlock Holmes, the self-proclaimed world’s only consulting detective, is the paragon of clever reasoning, famous for startling leaps of inference. Any of his appurtenances—the deerstalker hat, the pipe, the magnifying glass—is enough to evoke observation and cool-headed rationality. And, despite his singular occupation, he offers a lesson for the rest of us on the uses of scientific thinking in everyday life.

Arthur Conan Doyle draws readers into the process of detection with what his biographer John Dickson Carr called “enigmatic clues.” Holmes signposts a piece of evidence as significant but doesn’t immediately reveal its use, leaving it as an exercise for the reader. “The creator of Sherlock Holmes invented it,” Carr wrote in 1949, “and nobody … has ever done it half so well.” In one of the most celebrated examples, Sherlock Holmes quizzes a client about the “curious incident of the dog in the night-time.” “The dog did nothing in the night-time,” the man says. “That was the curious incident,” remarks Holmes.

Spectacular detective An illustration by Frederic Dorr Steele that accompanied the 1904 publication of ‘The Adventure of the Golden Pince-Nez’ in Collier’s magazine.