Sir Arthur Conan Doyle (2014). “Sherlock Holmes Complete Collection With illustrated Adventures of Sherlock Holmes - 4 Novels, 56 Short Stories and 120+ illustrations”, p.232, Ageless Reads
Address at the Sorbonne, Paris, 23 Apr. 1910. Richard M. Nixon quoted this passage in his address to the nation announcing his decision to resign the presidency, 8 Aug. 1974. See Theodore Roosevelt 1; Theodore Roosevelt 2; Theodore Roosevelt 5