“There is an Aristotelic tradition in cognitive psychology, information design and artificial intelligence, to understand human information processing as a mechanism, that is, as a complicated system, ultimately explainable on the basis of the understanding of every one of its multiple components and their interactions. Instead of looking at human information processing as a complicated system, I propose to look at it as a complex system, distinguishing for this paper the complicated from the complex; the first being composed by a high number of discrete parts with many interconnections: as in a computer circuit, the second being an integrated system where everything affects everything: as in the relation between two people.”