<P> Van Rilliaer could have also mentioned that Eduard von Hartmann published a book dedicated to this topic, Philosophy of the Unconscious, in 1869--long before anybody else . </P> <P> Furthermore, 19th century German psychologists, Gustav Fechner and Wilhelm Wundt, had begun to use the term in their experimental psychology, in the context of manifold, jumbled sense data that the mind organizes at an unconscious level before revealing it as a cogent totality in conscious form ." </P> <P> Sigmund Freud and his followers developed an account of the unconscious mind . It plays an important role in psychoanalysis . </P> <P> Freud divided the mind into the conscious mind (or the ego) and the unconscious mind . The latter was then further divided into the id (or instincts and drive) and the superego (or conscience). In this theory, the unconscious refers to the mental processes of which individuals make themselves unaware . Freud proposed a vertical and hierarchical architecture of human consciousness: the conscious mind, the preconscious, and the unconscious mind--each lying beneath the other . He believed that significant psychic events take place "below the surface" in the unconscious mind, like hidden messages from the unconscious . He interpreted such events as having both symbolic and actual significance . </P>

Psychologist who focuses on the role of the conscious and unconscious mind