In German folklore, every human, bird, and beast had a spirit double, an identical but usually invisible match. These apparitions were not considered ghosts (ghosts only appear after death) and they sometimes were described as the spiritual opposite or negative of their human counterparts. In fact, it was believed that to meet one's double would be a sign that one's death is imminent.

In 1796, German writer Johann Paul Richter, who wrote under the pseudonym Jean Paul, dubbed such specters doppelgangers – literally, double goers. The term was borrowed into English in 1851.