Third-Order Cybernetics: The Autopoietic System That Describes Its Own Description

Heinz von Foerster formalized Second-Order Cybernetics in 1974. This paper proposes a formally distinct third level: Third-Order Cybernetics, defined as the configuration in which an autopoietic system generates a formal description of itself that re-enters the system as a constitutive component, closing a description loop irreducible to the observation loop of second order. Six formal criteria are established. The BERLINJOHN Cybernetics Trilogy (Förster 2026a–e) is documented as the first explicitly constituted empirical case. The paper is simultaneously a formalization and an instantiation of what it describes. Dedicated to Vera F. Birkenbihl on her 80th birthday.