General living systems theory is concerned with seven levels of living systems—cell, organ, organism, group, organization, society, and supranational system. An exposition of the basic concepts in this theory appeared in “Living Systems: Basic Concepts,” Behavioral Science, 1965, 10, 193–237. (See also “Living Systems: Structure and Process,” and “Living Systems: Cross-Level Hypotheses,” Behavioral Science, 1965, 10, 337–411.) A condensation of the basic concepts also appeared in “The Nature of Living Systems,” Behavioral Science, 1971, 16, 277–301, which is reprinted beginning on the next page. Following that is an analysis in terms of this conceptual system of present knowledge concerning one level of living system—the society. In order to emphasize the cross-level formal identities among levels of living systems, this article follows exactly the same outline as other articles written by the author on the cell (“Living Systems. II. The Cell,” Currents in Modern Biology, 1971, 4, 78–206), the organ (“Living Systems. III. The Organ,” Currents in Modern Biology, 1971, 4, 207–256), the organism (“Living Systems. II. The Organism,” Quarterly Review of Biology, 1973, 48: 1 (Pt 2), 92–276), the group (“Living Systems: The Group,” Behavioral Science, 1971, 16, 302–398), and the organization (“Living Systems: The Organization,” Behavioral Science, 1972 17, 1–182). Their subheadings and section numbers are identical. All these articles will also be published as chapters of the author's forthcoming book Living Systems (New York: McGraw-Hill, 1976). Another chapter in that book, also following the same outline, will analyze current knowledge about the highest level of living systems—the supranational system. Since anatomists and physiologists are usually laymen in organization theory or international relations, psychologists are commonly laymen in economics, and social scientists are ordinarily laymen in cellular biology, all parts of the book, including the article published here, are necessarily written for intelligent laymen rather than experts, even though the articles deal with many technical topics. Some statements in them will seem to experts to be too elementary to be worth repeating. If a fact is fundamental and may not be known to specialists in other fields, it is stated here, even if it is elementary to the experts. The complex division of labor of modern science, often characterized by pluralistic insularity, requires this. The multitude of detailed and specialized experiments and studies that have been carried out provide the substance of the scientific investigation of organizations. Their findings constitute the trees. But an overview of these results and of the relationships among them—a view of the forest—is also essential. Such a telescopic rather than a microscopic view may suggest the proper balance for research on various aspects of society and clarify the priorities for future efforts. Many ideas presented here are not original with the author, though the arrangement is. Unless several persons have wrestled with an idea it is often not fundamental. The author has necessarily selected only a few researches to discuss out of the vast published repertoire, and so his selection has necessarily been arbitrary. Experts in each special field might agree on other studies as more important. Some of the author's statements may be wrong and his analysis ill advised. If so he would appreciate corrections—it is hard to cover such a wide range and still make no errors. The discussion of the processes of each subsystem ends with a number of examples of the variables of that subsystem which can be observed and measured. These variables make concrete the content of science at this level. They appear also to be common for a particular subsystem at multiple levels of living systems. Measurement of these variables, therefore, can be one way to determine whether cross-level formal identities exist. Throughout the text there are numerous references to cross-level hypotheses. These are mentioned for a similar purpose—to show that propositions possibly valid at other levels may also apply to societies. These hypotheses, numbered to indicate the section of the article to which they apply, appear on pages 366–368 of the article on the society. Many of them have been shown in other articles to be relevant to other levels of living systems as well. At each level there are scientists who apply systems theory in their investigations. They are system theorists but not necessarily general systems theorists. They are general systems theorists only if they accept the more daring and controversial position that—though every living system and every level is obviously unique—there are important formal identities of large generality across levels. These can potentially be evaluated quantitatively, applying the same model to data collected at two or more levels. This possibility is the chief reason why the author has used the same outline with identically numbered sections to analyze the present knowledge about each of the seven levels of living systems. The following survey of what is known about societies as systems, therefore, is to be read as a single segment of a larger, integrated whole.