This book presents the best and most important writings of J. L. Moreno in one concise and accessible place. This unique collection explores Moreno’s thought in developing psychodrama and sociometry, with his strong emphasis on spontaneity and creativity. The book discusses both basic and advanced concepts and techniques of psychodramatic treatment. Jonathan Fox introduces the book with a brief overview of Moreno’s life and ideas and places him in the context of his time and in the field of psychotherapy. Fox’s notes throughout underscore significant aspects of the selections for the practitioner and student. The essence of sociometry lies in the idea that groups have an internal life of their own and that this life can best be understood by examining the choices members make at any given moment with regard to each other. The book consists entirely of protocols that show Moreno at work directing psychodrama and sododrama, and contains autobiographical fragments. One of the basic instruments in constructing a patient’s psychodramatic world is that of the auxiliary ego, which is the representation of absentee individuals, delusions, hallucinations, symbols, ideals, animals, and objects. The psychodramatic method uses mainly five instruments—the stage, the subject or actor, the director, the staff of therapeutic aides or auxiliary egos, and the audience. All group methods have in common the need for a frame of reference for assessing the validity of their findings and applications. Spontaneity is often erroneously thought of as being more closely allied to emotion and actions than to thought and rest. The sociometric test is an instrument which examines social structures through the measurement of the attractions and repulsions which take place between the individuals within a group.