Doppelgänger

Doppelgänger literally means “double-goer” in German. In modern use it describes an uncanny living double, sometimes interpreted as an omen or supernatural counterpart. Similar ideas occur elsewhere, including the Irish and English “fetch,” but those terms arise from distinct traditions and are best treated as parallels rather than exact synonyms.

The German term entered literary use around the turn of the nineteenth century and flourished in Romantic and Gothic writing. Its themes—divided selfhood, mistaken identity, and the fear of replacement—made it especially durable in psychological fiction.

Film and television often make a double an evil duplicate or shape-changing infiltrator. Folklore and literature also allow for visions, omens, social confusion, or symbolic divisions within one person.

• Oxford English Dictionary, “doppelgänger,” etymology and usage history.
• John Herdman, The Double in Nineteenth-Century Fiction, Palgrave Macmillan, 1990.