Activity is youth and sluggishness or paralysis is age. Hence the
energy, initiative, adaptability, and receptivity to new ideas--all
youthful qualities--which characterize the Anglo-Saxon American as well
as the English Africander, can be traced back to the stimulating
influences, not of a bracing or variable climate, but of the abundant
opportunities offered by a great, rich, unexploited country. Variation
under new natural conditions, when safe-guarded by isolation, tends to
produce modification of the colonial type; this is the direct effect of
a changed environment. But the new economic and social activities of a
transplanted people become the vehicle of a mass of indirect geographic
influences which contribute to the differentiation of the national
character.

[Sidenote: General importance of indirect effects.]

The tendency to overlook such links between conspicuous effects and
their remote, less evident geographic causes has been common in
geographic investigation. This direct rather than indirect approach to
the heart of the problem has led to false inferences or to the
assumption that reliable conclusions were impossible. Environment
influences the higher, mental life of a people chiefly through the
medium of their economic and social life; hence its ultimate effects
should be traced through the latter back to the underlying cause. But
rarely has this been done. Even so astute a geographer as Strabo, though
he recognizes the influence of geographic isolation in differentiating
dialects and customs in Greece,[25] ascribes some national
characteristics to the nature of the country, especially to its climate,
and the others to education and institutions. He thinks that the nature
of their respective lands had nothing to do with making the Athenians
cultured, the Spartans and Thebans ignorant; that the predilection for