ian approach to describe evolutionary phenomena at a prebiologi- cal, molecular level.
Autopoiesis—the Organization of the Living
The hypercycles studied by Eigen self-organize, self-reproduce, and evolve. Yet one hesitates to call these cycles of chemical reactions “alive.” What properties, then, must a system have to be called truly living? Can we make a clear distinction between living and nonliving systems? What is the precise connection between self-organization and life?
These were the questions the Chilean neuroscientist Humberto Maturana asked himself during the 1960s. After six years of studies and research in biology in England and the United States, where he collaborated with Warren McCulloch’s group at MIT and was strongly influenced by cybernetics, Maturana returned to the University of Santiago in 1960. There he specialized in neuroscience and, in particular, in the understanding of color perception.
From this research two major questions crystallized in Maturana’s mind. As he remembered it later, “I entered a situation in which my academic life was divided, and I oriented myself in search of the answers to two questions that seemed to lead in opposite directions, namely: ‘What is the organization of the living?’ and ‘What takes place in the phenomenon of percep-
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Maturana struggled with these questions for almost a decade, and it was his genius to End a common answer to both of them. In so doing, he made it possible to unify two traditions of systems thinking that had been concerned with phenomena on different sides of the Cartesian division. While organismic biologists had explored the nature of biological form, cyberneticists had attempted to understand the nature of mind. Maturana realized in the late sixties that the key to both of these puzzles lay in the understanding of “the organization of the living.”
In the fall of 1968 Maturana was invited by Heinz von Foerster to join his interdisciplinary research group at the University of
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THE WEB OF LIFE
Illinois and to participate in a symposium on cognition held in Chicago a few months later. This gave him an ideal opportunity to present his ideas on cognition as a biological phenomenon. 41 What, then, was Maturana’s central insight? In his own words:
My investigations of color perception led me to a discovery that was extraordinarily important for me: The nervous system operates as a closed network of interactions, in which every change of the interactive relations between certain components always results in a change of the interactive relations of the same or of other components.” 42
From this discovery Maturana drew two conclusions, which gave him the answers to his two major questions. He hypothesized that the “circular organization” of the nervous system is the basic organization of all living systems: “Living systems . . . [are] organized in a closed causal circular process that allows for evolutionary change in the way the circularity is maintained, but not for the loss of the circularity itself.” 43
Since all changes in the system take place within this basic circularity, Maturana argued that the components that specify the circular organization must also be produced and maintained by it. And he concluded that this network pattern, in which the function of each component is to help produce and transform other components while maintaining the overall circularity of the network, is the basic “organization of the living.”
The second conclusion Maturana drew from the circular closure of the nervous system amounted to a radically new understanding of cognition. He postulated that the nervous system is not only self-organizing but also continually self-referring, so that perception cannot be viewed as the representation of an external reality but must be understood as the continual creation of new relationships within the neural network: “The activities of nerve cells do not reflect an environment independent of the living organism and hence do not allow for the construction of an absolutely existing external world.” 44
According to Maturana, perception and, more generally, cognition do not represent an external reality, but rather specify one
MODELS OF S E L F - O R G A N I Z A T I O N