Armchair detective an arm-chair, my brother would be the greatest criminal agent that ever lived." "The first example of armchair detecting can be found in the work of Edgar Allan Poe. In "The Mystery of Marie Rogêt" (1842), C. Auguste Dupin, working wholly from newspaper accounts, arrives at the correct explanation for a young woman's mysterious disappearance." Baroness Orczy's Old Man in the Corner sits in a restaurant and talks to an acquaintance about cases, almost always finishing by revealing that he has solved the crime. A more literal use of this term can be found in Rex Stout's Nero Wolfe novels
Louis Ellies Dupin Louis Ellies Dupin Louis Ellies du Pin, or Dupin (17 June 1657 – 6 June 1719) was a French ecclesiastical historian, who was responsible for the "Nouvelle bibliothèque des auteurs ecclésiastiques " Dupin was born at Paris, coming from a noble family of Normandy. His mother, a Vitart, was the niece of Marie des Moulins, grandmother of the poet Jean Racine. When ten years old he entered the college of Harcourt, where he graduated M.A. in 1672. At the age of twenty Dupin accompanied Racine, who made a visit to Nicole for the purpose of becoming reconciled to the gentlemen