In the 40 years since Ruth C. Cohn developed theme-centered interaction (TCI), it has grown from an educational-therapeutic model to a comprehensive concept aimed at addressing personality development and group leadership. TCI allows the learning and working processes of individuals, groups, teams and organizations to be reflected on, controlled, and managed. Processes of life-work balance can also be coordinated with TCI and empowerment furthered. Today, TCI is successfully being employed in adult education, schools, businesses, counseling and pastoring settings, manager development and training, and in many other areas. This volume contains 53 short contributions highlighting the central concepts of TCI, their origin, and further development. It thus provides a state-of-the-art look at this concept in a clear, systematic, and scientifically sound manner. This handbook represents at once a theoretical treatise, a textbook for anyone desiring information about TCI, for persons presently undergoing TCI training, who are teaching TCI, applying it or doing scientific research on this subject. A uniform structure in most texts enables the reader to quickly and efficiently compare different subjects.