The book is devoted to the analysis of the legacy of G. P. Shchedrovitsky (1929–1994) - an outstanding Russian thinker, philosopher, methodologist, public and cultural figure, organizer and leader of the Moscow Methodological Circle (MMK). The collection includes articles by MMK participants, students and followers of G.P. Shchedrovitsky, which consider only the main topics from his extensive and still little-studied heritage: problems of the theory of thinking and activity, semiotics and epistemology, the system-thought-activity approach, organizational-activity games. The book publishes for the first time a report by G. P. Shchedrovitsky in 1972, dedicated to the idea of activity and the activity approach, as well as a complete bibliography of the works of G. P. Shchedrovitsky and works about him. The book is recommended for specialists in philosophy, methodology of science, students, graduate students, and also to a wide range of people who are interested in the intellectual history of modern Russia.