In a time in which an exuberant, trans-classical, non-trivial machine culture redesigns terminologies, remodels logics, produces new evidence, and reorganizes semantic resources, a new, neocybernetic regime of truth is taking shape. Many of our recent self-descriptions and theory formations are coined by our media-technological condition. Nowhere is this more apparent than in the work of Niklas Luhmann, especially in his inherent narrative of the history of rationality. This essay attempts to reconstruct Luhmann’s redescription of European rationality, especially the media- and machine-historical conditions that remain apparent in Luhmann’s account. The decisive issue is that Luhmann’s history of rationality reveals the technological unconscious of systems theory and indeed the epochal imaginary it belongs to. With the help of the theories of machines developed by von Foerster, Simondon and Günther, Luhmann’s oeuvre must be read as probably the most striking conceptual edifice to emerge from what could be called the 20th-century’s epochal technological shift of meaning.