By a detailed investigation of dreams Freud discovered a way of exploring the unconscious, recognized that dreams, like neurotic symptoms, are products of a conflict and compromise between conscious and unconscious impulses and was able to classify the differences between the primary and secondary processes of thought - between the modes of functioning in the unconscious and conscious regions of the mind. In addition, Freud was led to revise his methods of treatment for neurotic patients by introducing the valuable technical adjunct of dream-interpretation and to develop, largely based on this work, his revolutionary theories of the Oedipus complex and on the profound importance of infantile life and sexuality for the development of adults.