This is Freud's greatest and most important work in which he introduces his theory of the unconscious with respect to dream interpretation, and also first discusses what would later become the theory of the Oedipus complex, and it is widely considered one of his most important works. Freud said of this work, «Insight such as this falls to one's lot but once in a lifetime.» Dreams, in Freud's view, are all forms of «wish fulfillment» – attempts by the unconscious to resolve a conflict of some sort, whether something recent or something from the recesses of the past. Because the information in the unconscious is in an unruly and often disturbing form, a «censor» in the preconscious will not allow it to pass unaltered into the conscious. Freud refers to dreams as «The Royal Road to the Unconscious». He proposed the 'phenomenon of condensation' – the idea that one simple symbol or image presented in a person's dream may have multiple meanings. Content: THE SCIENTIFIC LITERATURE ON THE PROBLEMS OF THE DREAM METHOD OF DREAM INTERPRETATION THE DREAM IS THE FULFILMENT OF A WISH DISTORTION IN DREAMS THE MATERIAL AND SOURCES OF DREAMS THE DREAM-WORK THE PSYCHOLOGY OF THE DREAM ACTIVITIES Sigmund Freud (1856-1939) was an Austrian neurologist and the father of psychoanalysis, a clinical method for treating psychopathology through dialogue between a patient and a psychoanalyst.