Maturana and Varela’s compact statement of the biology of cognition: knowing is not a picture of the world sitting inside a skull. It is what a living system does as it couples with its niche - and every act of doing already is a form of knowing. The line comes from The Tree of Knowledge (Spanish 1984; English 1987), the book that carried autopoiesis and enaction into a wider conversation. If all knowing is doing, then theories, classrooms and dashboards are never the whole story; the body in the world is. That is why the couplet sits so well beside No. 34 “Descartes is dead” and No. 43 “Where there is life there is mind”: mind is not a ghost. It is life at work.