Doubling is a literary device that is used to compare or contrast the familiar with the strange. It is most commonly used in Gothic literature where characters are literally or figuratively doubled in order to examine a hidden nature or desire.
An example of literary doubling can be found in "The Strange Case of Dr Jekyll and Mr Hyde" by Robert Louis Stevenson, where the main character physically changes into an evil, carnal and savage version of himself. By doing so, Stevenson is able to examine the question of the presence of good and evil in an individual.
In "Dracula" by Bram Stoker, the characters of Dracula and Van Helsing also exemplify literary doubling in that they are connected and similar to one another through their strangeness. However, they are different in the ideals that they adhere to.
Literary doubling in Gothic literature was also used as a means of examining the break down of the Victorian aristocracy during the 18th and 19th centuries. Prior to this time, the aristocracy in England held unquestioned authority as the head of society. As the aristocracy began to fall apart, the break up began to appear in the Gothic literature of the time such as Mary Shelley's "Frankenstein," in which literary doubling takes the form of a monster and an aristocratic family.