211. Sources of Knowledge
The story of the growth and development of culture in the Western Hemisphere which has been sketched in reconstruction in the last chapter is built up from the incomplete information of excavations and the indirect evidence of culture trait distributions and analyses. Earlier than about ten thousand years ago, this hemisphere has no known human history. In the Old World, conditions are doubly different. There is a long primeval record, stretching perhaps a hundred thousand years beyond 8000 B.C., documented much like the subsequent culture history of America, but with a wealth of geological, faunal, and skeletal data to compensate for the loss of ancient cultural evidences in the lapse of time. Secondly, for the last ten thousand years, there is a fuller record than for America. This greater fullness is partly due to the earlier start toward its higher forms which civilization took in the Eastern Hemisphere. And this relatively early advancement brought it about that by 3000 B.C. adequate systems of writing had been achieved in Africa and Asia, so that contemporary inscriptions have been preserved to throw direct light on the thoughts and institutions of the people of that day, and to date the centuries of their rulers for us. These last five thousand years thus belong to history, rather than to prehistory, in some parts of the hemisphere; and they allow many a close inference as to what happened in the previous five thousand years when writing was as yet unknown or its first systems were being evolved.
These ten thousand years since the close of the Old Stone Age, half of them studied by the methods of anthropology, half also by those of history, and the whole forming the richest field in human culture history, are the subjects of the present chapter and the next.
First, however, it is necessary to refer back to the earliest known development of civilization in the Old Stone Age (Chapter [VI]), whose close is our present starting point.