ABSTRACT
In Niklas Luhmann's vision of the modern functionally differentiated society, health presents one of the essential function systems, along with politics, law, economy and science. While he devoted much effort to elaborating the theoretical foundations of the latter function systems, his work on the health system was relatively sparse. This research gap has been rendered particularly acute by the recent COVID-19 crisis. In reconstructing and updating the Luhmannian analysis of this system, this article presents a three-dimensional concept of organic, psychic and social health and highlights the risks raised by a potential overexpansion of the health concept to the planetary level. The most important of these risks is shown to be the potential rise of totalitarian social control that exceeds classical forms of medical social control. The proposed argument not only contributes to the public criticism of the political responses to the COVID-19 crisis but also fills in some missing pieces of Luhmann's seminal elaboration of the health system.