“Quell’istante dove tutto ritorna possibile”. Le funzioni del negativo tra istituzioni immunitarie e movimenti sociali

Abstract: Luhmann’s sociological theory has been received and criticized in many respects. Among the topics that have not been considered as they deserve, there is one particularly relevant: that of social immunology. In the early 1980s, Luhmann began to imagine society’s immune system as being made up of symbols of rejection – the universe of ‘No’, in relation to that of ‘Yes’. As he wrote in the chapter of Soziale Systeme dedicated to contradictions and conflicts: “the system does not immunize itself against ‘no’, but rather with the help of ‘no’; it is not protected from changes, but thanks to changes”.The immune system does not protect structures (always transient), but only autopoiesis: it protects from annihilation through de-nial. Social contradictions perform the alarm function “destroying for an instant the global claim of the system to be already reduced and ordered complexity. For an instant, the inde-terminate complexity in which everything is possible is re-established”. In the following years Luhmann took up those seminal reflections to develop a theory where the ‘negative’ – where everything is possible – becomes an affirmative form and where the warning signals that soci-ety needs to react to highly problematic situations take on ever greater importance. With the theory of social movements, risk, and danger, Luhmann will then develop the foundations for understanding why and how society generates a real and capillary immune system