The article is an introduction to a special section in TCS on the work of Niklas Luhmann. The first part of the article provides a general introduction to Luhmann’s work with an emphasis on the basic elements of Luhmann’s general systems theory, in particular Luhmann’s notions of autopoiesis and meaning, and the traditions on which it is based. The second part of the text is a presentation of the articles in the special section.