Why does our body require two different modes of transmitting information vital for its survival? To answer this question, we need to take a detour down a path that may seem secondary to our main trajectory. This detour is not ornamental: it allows us to clarify what it means for a system to be “closed” under fixed rules, and why this ideal of complete formal control fails precisely where living systems, and the human brain in particular, must operate with open, evolving forms of information.