A psychoanalyst, through training and experience, directs the en- tire focus of his attention to registering and internalizing the in- put of a patient's communications, listening intently for their implied meanings. It is only by umaveling the mysteries of an un- conscious realm of mental activity that it becomes possible to fully comprehend the way in which mental productions are finally ob- servable. The psychoanalyst's total personality is the listening in- strument, and the messages emanating from this hidden sector most clearly heard, deciphered, and understood are those most resonant with the contents of the psychoanalyst's unconscious. It is probable that a variety of psychoanalysts adopting a listening posture with a given patient would hear and understand a mul- tiplicity of different meanings. Over the years, sensitive, well- trained psychoanalytic investigators have formulated concepts con- cerning mental functioning from disparate and often opposing points of view. These contradictory ideas are offered from a ba- sic theoretical foundation placing unconscious mental events as the most important force shaping human experience. Divergent opin- ions may at times appear irreconcilable and then serve as the grounds for developing a separate psychoanalytic school of thought. It is not surprising that an exploration of unseen powerful and regressive forces, by a group of scientists with unique in- dividual experiences, would yield insights sensitively attuned to a wide variety of important factors determining human develop- ment and behavior.