

Izaak Walton claimed that English metaphysical poet John Donne saw his wife's doppelgänger in 1617 in Paris, on the same night as the stillbirth of their daughter. The doppelgänger is a version of the Ankou, which is a personification of death that appears in Breton, Cornish, and Norman folklore.

In Finnish mythology, this pattern is described as having an etiäinen, "a firstcomer". This memic sense also appears in Euripides' play Helen, and in Norse mythology, a vardøger is a ghostly double who is seen performing the person's actions in advance. The Greek Princess presents an Egyptian view of the Trojan War in which a ka of Helen misleads Paris, helping to stop the war. In Ancient Egyptian mythology, a ka was a tangible "spirit double" having the same memories and feelings as the person to whom the counterpart belongs. However, the concept of alter egos and double spirits has appeared in the folklore, myths, religious concepts, and traditions of many cultures throughout human history. Francis Grose's, Provincial Glossary of 1787 used the term fetch instead, defined as the "apparition of a person living." Catherine Crowe's book on paranormal phenomena, The Night-Side of Nature (1848) helped make the German word well-known. In English, the word is generally written with a lower-case letter, and the umlaut on the letter "a" is usually dropped: "doppelganger"Įnglish-speakers have only recently applied this German word to a paranormal concept. In German, the word is written (as is usual with German nouns) with an initial capital letter: Doppelgänger. The first known use, in the slightly different form Doppeltgänger, occurs in the novel Siebenkäs (1796) by Jean Paul, in which he explains his newly coined word in a footnote the word Doppelgänger also appears in the novel, but with a different meaning.

The singular and plural forms are the same in German, but English writers usually prefer the plural "doppelgangers".

The word doppelganger is a loanword from the German Doppelgänger ( German pronunciation: ), a compound noun formed by combining the two nouns Doppel (double) and Gänger (walker or goer).
