The author of this book explores a particular mode of mental functioning expressed through a series of clinical symptoms and highlighted by contemporary psychosomatic research. Smadja's concept, a true clinical and conceptual invention in the field of psychopathology, has evolved from work originally carried out by Pierre Marty, Michel de M'Uzan, Christian David and Michel Fain, pioneers of the psychoanalytic approach to subjects with somatic illnesses. These authors, internationally known as the "psychosomaticists of the Ecole de Paris," have contributed extensively to our understanding of the relations between the life of the psyche and the working of somatic disease. Using his own clinical experiences as a psychoanalyst and psychosomaticist, the author significantly extends the study of "operational states" and their metapsychological implications.