Historical Context

There were three major sources of influence on the psychoanalytic movement: previous assumptions about the unconscious, early notions about psychopathology, and evolutionary theory.

Assumptions of the unconscious

As early as the eighteenth century, German philosopher and mathematician Gottfried Wilhelm Leibnitz developed the notion that there were degrees of consciousness ranging from completely unconscious to fully conscious. A century later, German philosopher Johann Friedrich Herbart refined Leibnitz's concept of the unconscious by stating that only conscious ideas are perceived in awareness. Gustav Theodore Fechner, who preceded Freud but had contact with him in the later part of the nineteenth century, also speculated about the unconscious. Fechner conceived the classic illustration of an...