Now available in paperback this classic text presents an integrated, multidisciplinary analysis of the nature of all biological and social systems. Any system, contends Miller, is organised, and operates at, seven hierarchical levels: cells; organs; organisms; groups; organizations; societies; and supranational systems. This detailed analysis looks at each of the major aspects and characteristics encountered at all seven levels. Multiple variables of each of the nine matter-energy and information-processing subsystems, the normal and pathological states of these variables, and practical indicators for measuring changes in them are identified. Miller argues that the interaction of matter-energy and information flow among systems at one level create the next higher level. Thus, all systems are unified.