As the earth is one, so is humanity. Its unity of species points to some
degree of communication through a long prehistoric past. Universal
history is not entitled to the name unless it embraces all parts of the
earth and all peoples, whether savage or civilized. To fill the gaps in
the written record it must turn to ethnology and geography, which by
tracing the distribution and movements of primitive peoples can often
reconstruct the most important features of their history.

Anthropo-geographic problems are never simple. They must all be viewed
in the long perspective of evolution and the historical past. They
require allowance for the dominance of different geographic factors at
different periods, and for a possible range of geographic influences
wide as the earth itself. In the investigator they call for pains-taking
analysis and, above all, an open mind.


NOTES TO CHAPTER I

[1] George Adam Smith, Historical Geography of the Holy Land, pp.
149-157. New York, 1897.

[2] A.P. Brigham, Geographic Influences in American History, Chap. I.
Boston, 1903.

[3] R.H. Whitbeck, Geographic Influences in the Development of New
Jersey, _Journal of Geography_, Vol. V, No. 6. January, 1908.

[4] Hans Helmolt, History of the World, Vol. II, p. 372. London and New
York, 1902-1906.