ABSTRACT
"Structure" is a key term in fields ranging from psychology to biology In his seminal monographStructuralism(1970), Jean Piaget discussed the challenge of formalizing structure. Piaget considers a structure to be "a system of transformations" that comprises three key ideas (ibid., p. 5):wholeness, transformation, andselfregulation."Wholeness" is a defining mark of structure, which is, to use the famous Gestalt phrase, more than the sum of its parts. The idea of "transformation" emphasizes the dynamic nature of structure and the fact that it is constituted (ibid., p. 13) as a system of transformations that map certain components of the system fromtto t›t'. According to this suggestion, a structure is never static but, like Heraclitus's river, is a constant flux that under certain transformations appears invariant to a specific observer. (As "structure" is sometimes associated with a time-invariant form, the term "pattern" will be used interchangeably.) The third basic property, self-regulation, entails self-maintenanceand closure (ibid., p. 14). It means that the internal dynamics of the system constitutes the structure as a phenomenologically differentiated form. The structure is therefore not a mold passively formed by external forces but a form that actively maintains its existence from 'within'.
