Some control conditions for self-organization--what the control theorist can learn from biology.

The general control task, as expressed formally in engineering science or mathematical systems theory, is presented briefly. Characteristics of technological control systems are then contrasted with the control processes revealed by molecular biology. It is emphasized that the control processes of living systems have certain features not represented in formal control theory. One of these features is the use of positive feedback in a novel way to achieve a "positive control potential." The environmental conditions necessary for positive control potential to arise are considered. It is concluded that achievements in life sciences offer a challenge to extend formal control theory into new domains, but at the same time, existing control theory helps to highlight what it is that living systems uniquely do, even though it cannot explain how they do it.