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The simplest form or structure we can imagine is a distinction. A distinction can be defined as the process (or its result) of discriminating between a class of phenomena and the complement of that class (i.e. all the phenomena which do not fit into the class). As such, a distinction structures the universe of all experienced phenomena in two parts. Such a part which is distinguished from its complement or background can be called an indication (Spencer-Brown, 1969). If more than one distinction is applied the structure becomes more complex, and the number of potential indications increases, depending on the number of distinctions and the way they are connected.

A distinction can be seen as an element of cognitive structuration. Indeed, any process of perception implies a classification between phenomena. This classification operation has two aspects :

  1. the phenomena which are put together in a class, are considered to be equivalent with respect to the observer's goals, they are assimilated, they belong to the same equivalence class ;
  2. the phenomena corresponding to different classes are distinguished or discriminated, they belong to different equivalence classes.
The operations of distinction, and assimilation of phenomena necessarily go together. If a cognitive system would make no distinctions, only assimilations, it would be unable to perceive different phenomena, it would react to all situations in a uniform way; hence, it would be unable to adapt to a changing environment. On the other hand, a system which would make no assimilations, only distinctions, would be unable to anticipate; hence it would also be unable to adapt.

Spencer-Brown (1969) has proposed general axioms for distinctions. With these axioms, he has shown that a set of distinctions has a Boolean algebra structure, isomorphic to the algebra of classes in set theory or to the algebra of propositions in logic (Spencer-Brown, 1969). Spencer Brown showed that distinction algebra implies propositional calculus. B. Banaschewski (1977) showed the opposite entailment in

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Copyright© 1997 Principia Cybernetica - Referencing this page

F. Heylighen,

Nov 25, 1997 (modified)
Sep 1991 (created)


Metasystem Transition Theory


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