At this mid-point in our discussion we shall shift from a structural taxonomy to a process taxonomy, in line with Bateson's model for mapping phenomena at increasing levels of complexity: the "zigzag ladder of dialectic between form and process." 1 It has been useful to note the early impressionistic descriptions of the flow of interaction in families that produce disturbed persons, and then to try to codify structures from the information provided by this flow. In families with psychotic members, in particular, generalizations about deviant and normative structures are ways of imposing an external order upon flow. One can snatch out of the booming, buzzing confusion of family interaction certain clear redundancies and say, "There it is, and there, and there again!"
The emphasis on structure, however, does not reflect the power of living systems to reorganize in sudden and transcendent ways. A recent paper by Paul Dell and Harold Goolishian examines the concept of "evolutionary feedback," a term developed by the physi-