hat enter into contemporary
group life. It is now desirable to search for certain common elements
that in all periods enter into the life of every group, whether
temporary or permanent, so that we may discover the constant factors
and the general principles that belong to the science of society. Some
of these have been referred to already among the characteristics of
social life, but in this connection it is useful to classify them for
closer examination.

First among these is the physical factor which conditions human
activity but is not a compelling force, for man has often subdued his
environment when it has put obstacles in his way. This physical
element includes the geographical conditions of mountain, valley, or
seashore, the climate and the weather, the food and water supply, the
physical inheritance of the individual and the laws that control
physical development, and the physical constitution of the group. A
second factor is the psychic nature of human beings and the psychical
interaction that goes on between individuals within the group and that
produces reactions between groups.

359. =The Natural Environment.=--The early sociologists put the
emphasis on the physical more than the psychic factors, and
especially on biological analogies in society. It seemed to them as if
it was nature that brought men together. Mountains and ice-bound
regions were inhospitable, impassable rivers and trackless forests
limited the range of animals and men, violent storms and temperature
changes made men afraid. Avoiding these dangers and seeking a
food-supply where it was most plentiful, human beings met in the
favored localities and learned by experience the principles of
association. Everywhere man is still in contact with physical forces.
He has not yet learned to get along without the products of the earth,
extracting food-supplies from the soil, gathering the fruits that
nature provides, and mining the useful and precious metals. The
city-dweller seems less dependent on nature than is the farmer, but
the urban citizen relies on steam and electricity to turn the wheels
of industry and transportation, depends on coal and gas for heat and
light, and uses winter's harvest of ice to relieve the oppressive heat
of summer. Rivers and seas are highways of his commerce. Everywhere
man seems hedged about by physical forces and physical laws.

Yet with the prerogative of civilization he has become master rather
than servant of na