Abnormal psychology has also its practical aspects. Its discoveries have made possible the psychic treatment of certain functional nervous disorders. Technically, this is known as psycho therapeutics. The interpretation Of these func tional states is based on the principle of the dissociation Of consciousness. But psychothera peutics would be in a very chaotic condition and barren Of results, were it not for abnormal psychology, for a scientific psychotherapeutics must be based upon a. Sound psychopathology.