What can I say about this extraordinary book? Read this as a companion book to “Autopoiesis and Cognition;” a beautiful and dense, but oftentimes impenetrable meditation on the nature of life. The concept of ‘Autopoiesis’ can wear thin from over-use, but this book sets out the conceptually weaker (in a good way) and wider ranging idea of ‘Autonomy’. We can see autonomy as a halfway house to full autopoiesis, one that is perhaps achievable in the near future by non-living Artificial Intelligence and Robotics. The focus is on systems that maintain and regulate their identity (organisational closure), but not necessarily their physical structure (structural closure). Varela explores this idea from a number of tantalising angles – a cellular automaton based simulation of autopoiesis (a step up on Conway’s ‘Game of Life’), Spencer-Brown’s Laws of Form with an additional recursive operator, autonomous systems as oscillating chemical reaction systems, and the immune system as an autonomous unity. Varela’s tragic death at the age of 54, was indeed a huge loss to science and philosophy.