There are three odd-bedfellow theses between the covers of this engaging but overextended book. The first is anthropological: before the relatively recent advent of the nation-state, man lived in peaceful, cooperative bands and tribes, undisturbed by the rivalries and invidious class distinctions which characterize modern social life. The second is philosophical: man is malleable. ""Human nature,"" like a chameleon, assumes the traits of the physical and social environment. Man alters his environment, and the altered environment, in turn, influences man's behavior. The third thesis: the cure for modern ills, or at least the appropriate tool for finding such a cure, is the judicious use of computers to create social models and the evaluation of the ""alternative futures"" these models approximately describe. North competently discusses the first two respectable, but hardly indisputable or novel, ideas. In a disciplined manner, he advocates a broader approach to social issues. Rather than compare the socialist with the capitalist state, for example, social thinkers should ask such more general--and fruitful--questions as: how, in prehistory and history, has man juggled the variables of population, technology, and resources? How has he balanced social cooperation with individual competition? North has no answers, merely an approach. The computer revolution and cybernetics in general--which North puts on a par with the Industrial Revolution--can help man to simulate different social organizations and, for the first time, to plan for the best of all possible futures. Whether such an awesome project is practical, North does not make clear. Neither do the three main themes coalesce. The book is a curious and inchoate mix of substantive anthropology, philosophical argument, and vague procedural recommendations.