J. L. Moreno, M.D., is recognized as the originator of sociometry and psychodrama, and was a prodigious creator of methods and theories of creativity, society, and human behavior. The methods and techniques he authored have been widely adopted; the theories and philosophy upon which the methods are founded have not, as they are frequently couched in language which is not easily understood. Moreno’s ideas about group psychotherapy have pretty well gotten lost, and what he considered his greatest contribution, sociometry, gets paid superficial attention by most psychodramatists . Group psychotherapy and psychodrama are both widely practiced but often based on non-Morenean theory, likely due to the inaccessibility of Moreno’s work. This book outlines Moreno’s early years (his religious phase), the philosophy on which the foundation of his methods are based, and a description of the three major methods Moreno originated: psychodrama, sociometry, and group psychotherapy. It provides a more systematic presentation of Moreno’s work and presents his philosophy and theory clearer, more understandable manner.