Luhmann's theory is fascinating and complex. It offers incomparably enlightening insights, references and research opportunities, but reveals its utility only after a quite high competence threshold. Using the reticular form of the glossary, this book makes the theory accessible while maintaining its complexity. Without being obstructed by knowledge gaps or by references to concepts presented elsewhere, readers inside and outside sociology get the required support to explore sociological systems theory and to engage with it. Luhmann himself, in his introduction, praises the form of the glossary to cope with the challenges of the theoretical description of our highly complex society.

Claudio Baraldi published several works in international books and journals on communication systems. His research concerns interaction systems related to facilitation of children's participation, interlinguistic and intercultural mediation, conflict management. Giancarlo Corsi worked and published intensely on the theory of social systems, public opinion and communication media, education, career and social inclusion. His current research deals with the relationship between public sphere, mass media, and new communication technologies. Elena Esposito published many works on the theory of social systems, media theory, memory theory, and sociology of financial markets. Her current research on algorithmic prediction is supported by a five-year Advanced Grant from the European Research Council. She is a member of the scientific advisory board of Bielefeld University Press.