This linguistically oriented article contrasts the linguistic signifier with the psychoanalytic signifier. A signifier, for de Saussure, contained the signified as a concept. The psychoanalytic signifier, however, has the instinctual representative as its content. With this claim in mind, the authors study Freud's five case histories for the use he makes of psychoanalytically important signifiers, such as the word "rat" in the Rat Man case. They claim that Freud made enormous use of this linguistic characteristic to enable him to understand the unconscious conflicts of the individuals he studied.