A Freudian slip, also called parapraxis, is an error in speech, memory, or physical action that is interpreted as occurring due to the interference of an unconscious subdued wish or internal train of thought. The concept is part of classical psychoanalysis.
Classical examples of parapraxes involve slips of the tongue and , but psychoanalytic theory also embraces misreadings, mishearings, temporary forgettings, and the mislaying and losing of objects.
The Freudian slip is named after Sigmund Freud, who, in his 1901 book The Psychopathology of Everyday Life, described and analyzed a large number of seemingly trivial, bizarre, or nonsensical errors and slips, most notably the Signorelli parapraxis.
Freud, himself, referred to these slips as Fehlleistungen (meaning "faulty actions", "faulty functions" or "misperformances" in German); the Greek term parapraxes (plural of "parapraxis", from the Greek παρά [para] and πρᾶξις [praxis], meaning "another action" in English) was the creation of his English translator, as is the form "symptomatic action".
Freud's process of psychoanalysis is often quite lengthy and complex, as was the case with many of the dreams in his book The Interpretation of Dreams (1899). An obstacle that faces the non-German reader is that Freud's emphasis on 'slips of the tongue' leads to the inclusion of a great deal of material that is extremely resistant to translation.
As in the study of dreams, Freud submits his discussion with the intention of demonstrating the existence of unconscious mental processes in the healthy:
In the same way that psycho-analysis makes use of dream interpretation, it also profits by the study of the numerous little slips and mistakes which people make—symptomatic actions, as they are called [...] I have pointed out that these phenomena are not accidental, that they require more than physiological explanations, that they have a meaning and can be interpreted, and that one is justified in inferring from them the presence of restrained or repressed impulses and intentions. [Freud, An Autobiographical Study (1925)]