PAST, PRESENT, AND FUTURE	443
Two important elements have determined the course of
civilisation : (a) Man; (b) Environment. The variation
in the two factors accounts for the variations in cultures.
The different races of mankind (like Aryan, Semitic, Mon-
golian, Negro, etc.) have displayed different aptitudes for
culture; consequently, each of them -has evolved a culture
of its own. Thus the Aryan has differed from the Semitic,
and both from the Mongolian; the Negro has been the
least progressive. On the other hand, geographical or phy-
sical environment has equally influenced the course and char-
acter of people's progress. This includes the fertility of
soil, the nearness of rivers and the sea, climate, vegetation
and natural resources like minerals, building materials, etc.
Especially in the earlier stages of human civilisation these
were more decisive factors than they are now.
A culture once developed in a particular environment has
undergone considerable modification by contact with other
cultures; such contacts being determined by the means of
communication. The earliest means of communication were
rivers. The sea or ocean which was at first a dividing fac-
tor later became a uniting link between distantly situated
countries, on account of the progressive improvement of navi-
gation. Even vast continents in modern times have been
traversed by railways. The latest contrivance for the abridg-
ment of long distances is the airship. Telegraphs, deep-sea
cables, and the radio, have converted our world into a close-
knit sphere. This has led to the domination of weaker
cultures by the stronger, as wdl as resulted in a rapid pro-
cess of dimination of differences, producing a greater uni-
formity of dviiisation.
Nations like individuals have their own peculiarities. They
tend to preserve their special features, even as individuals
seek to preserve their personalities. But in our inter-depen-