Keywords: Science, System, Hierarchy Systems: None Summary: Chapter 1: Distinguishes between natural and "artificial" sciences. Discusses the relationship between artifacts and environments. Proposes that descriptions of artifacts can be viewed as "interfaces", i.e. interactions between internal and external environments. Examines the role of computers to this theory, both as tools for simulating systems and as complex systems in their own right. Notes that one key example of simulation is the simulation of human intelligence. Chapter 4 (Chapters 7, second edition): Suggests the idea of a domain independent "general systems theory." Argues that hierarchical organization is a key component of a wide variety of complex systems. Further argues that the process of evolution inherently tends toward hierarchical systems. Provides a wide variety of examples. Discusses a class of systems called "nearly decomposable systems" which can be viewed as hierarchical to a reasonable degree of approximation. Observes that hierarchical systems can generally be described more elegantly than completely chaotic systems. Discusses the relationship between state and process descriptions (e.g. a mathematical definition of a circle and a construction algorithm for a circle). Further relates this topic to the relationship between ontogeny and phylogeny in biology and other fields.