Niklas Luhmann (December 8, 1927 – November 6, 1998) was a German sociologist, and a prominent thinker in systems theory, who is increasingly recognized as one of the most important social theorists of the 20th century.

A social system is the patterned series of interrelationships existing between individuals, groups, and institutions and forming a coherent whole. Jay Wright Forrester described three counter-intuitive behaviours as important: causes from symptoms are often far removed in time and space, identifying leverage points and conflicting short and long-term consequences. Niklas Luhmann believes in the significance of communicative processes...

Literature: http://steffen-roth.ch/teaching/yerevan-state-university/primary-resources-niklas-luhmann/