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.