The ultimate purpose of the study of world history, most of us would probably agree, is to provide comprehensive perspectives on the human historical experience. Such perspectives obviously must be long as well as large, capable of highlighting powerful continuities along with the decisive turning points, while emphasizing both the diversity and the common denominators of humanity's past. From these assumptions it surely follows that one way world historians must expand their field of vision is through the integration of what we have learned to call prehistory with our customary consideration of events since the advent of ancient Sumer. The task is daunting, for if we want to take more than a cursory look at the origins of humankind, then we must be prepared to venture into the foreboding-and forbidden-- domain of the anthropologist, whose assumptions, methods, and source materials are sometimes unfamiliar to us, and whose slender bodies of evidence often preclude the possibility of firm conclusions and seldom yield the narrative detail historians regard as essential to their tasks. Whatever our hesitations, we might overcome them by reminding ourselves of the compelling reasons for mounting a serious dialogue between the two disciplines, particularly with the problem of interpreting prehistory in mind. For more than 99 percent ofthe time our hominid ancestors lived on this earth, they functioned within hunting-gathering contexts. Much of what makes us human evolved in our pre-agricultural past. Moreover, the principal components of the other major human adaptations defined and systematically studied by anthropologists---pastoralism, the agricultural village, and the city-had emerged by the end of the Neolithic period. As a consequence of their efforts to understand the patterns of prehistory, anthropologists have also been compelled to wrestle with a variety of important theoretical issues. As world historians, we can profit from their thinking about how cultures relate to their total environments and why they change over time.