MOO T POINTS IN SOCIOL OGY $2?
movements, he sees motion following the line of least resistance. " Religion, morals, philosophy, science, literature, art, and fashion, are all subject to the law of rhythm." The integration, differ- entiation, and segregation that go on in society have like causes with the corresponding cosmic processes.
It is hard to find warrant for this dual interpretation. After an activity has been explained in terms of motive, why re-explain it in terms of energy? If a principle such as men go where they can most easily satisfy their wants accounts for the currents of migration, why interpret them on the principle that motion follows the line of least resistance? If the rhythms that appear in every field of interest from dress to religion occur because "attention demands change in its object," why class them with rhythms due to "conflict of forces not in equilibrium." As for the processes of integration, differentiation, and segregation among men, I have already shown that they differ in principle from the processes of cosmic evolution.
A more common error is the assumption that social phe- nomena are to be interpreted as the interaction of two sets of factors, one external, the other internal. Under such terms as race and locality, man and environment, folk and land, this dualism constantly occurs in sociological writing.
There are, no doubt, social processes which may properly be said to have both internal and external causes. The numerical movement of population may be conceived as the product of psychic factors procreative impulses, desire for offspring, etc. which determine the birth-rate, with physical factors seasons, crops, etc. which determine the death-rate. Again, the size of a crop depends upon the acreage (which men can control) and upon the weather (which men cannot control). The herring catch depends at once on the desire for herring and on the size of the "run."
Most of the instances, however, that form the stock-in-trade of the environment school do not support their case at all. Migrations and colonizations, the territorial distribution of popu- lation, the distribution of labor among the various occupations, the investment of capital, the location of cities, the lines of
