elementary, my dear Watson

A statement apparently addressed by Sherlock Holmes, the fictional detective and protagonist of many stories by the British author Arthur Conan Doyle (1859–1930), to his friend Dr. John H. Watson. Although Holmes occasionally states that his conclusions are “elementary” and often addresses his friend as “my dear Watson”, the exact phrase does not appear in any of Doyle’s stories. The closest is the following passage from “The Crooked Man” (1893): “‘I have the advantage of knowing your habits, my dear Watson,’ said he [Holmes]. […] ‘Excellent,’ I [Watson] cried. ‘Elementary,’ said he.”

The phrase probably originated from the play Sherlock Holmes (1899) by the American actor and playwright William Gillette (1853–1937), based on Doyle’s stories, which featured the phrases “Elementary, my dear fellow” and “my dear Watson”. The play was revised many times, and thus it has been suggested that over the course of many performances “Elementary, my dear Watson” was also spoken. Subsequently, the phrase was probably popularized by its use in the series of 14 Sherlock Holmes films (1939–1946) starring the British actors Basil Rathbone as Holmes and Nigel Bruce as Watson.