Observers and Systems

Ashby’s cybernetic triad

  • Machine (that what is observed) – System (a set of variables selected by the observer) – Model (organized structure made from system variables for study). (Design for a Brain chapter 2/5 see also Stuart Umpleby)
  • Variable (noun) – a select element, feature, or factor (property) that is liable to vary or change. The state of the system is defined by the current value (vector) of all selected variables
  • A variable must be a quantifiable entity within well defined boundaries.
  • Note: Most discussions about systems do not make a clear distinction between machine and system. The difference is the same as between an observed object shaped as a triangle and the concept of a triangle. The system is just an idealized concept of some selected set of the machine’s properties.
  • Systems and machines exist in two different (non-intersecting) phenomenal domains that are internal and external to the observer
  • However, the model and the machine exists in the same phenomenal domain external to the observer.
  • Confusing this three terms is usually causing most issues during the discussion.

The Observer

Maturana Biology of Cognition, 1970

“Indeed, everything said is said by an observer to another observer that could be him or herself”
  • The observer is a living (autopoietic) machine.
  • In the beginning there was the observer. And the observer used signs, sounds and words to describe (model) that what was observed.
  • The oldest type of modelling is storytelling.
  • The model is the message constructed by the observer for conveying his information to another observer. See Maturana’s explanations for further details.


  • Not a commodity to be exchanged between systems (machines) but rather represents the state of the system