Greater than the sum of its parts. II. Matter-energy processing subsystems.

Behavioral science theory has changed greatly since 1978, when Miller's Living Systems was published. Much of the change represents progress, particularly in the biological fields. During that time, living systems theory (LST) developed in many ways. Among the most significant developments have been the addition of another level, the community, to the seven levels previously included in LST and the addition of another subsystem, the timer, to become the 20th subsystem. The present article is the second to be published in this journal which describe relatively briefly and simply the current state of scientific knowledge about the subsystems of living systems. It deals with the first six matter-energy processing subsystems, the ingestor, distributor, convertor, producer, matter-energy storage, and extruder.