register the disintegration of the moral order, for
example, the statistics of divorce, of truancy, and of crime.

Great cities have always been the melting-pots of races and of cultures.
Out of the vivid and subtle interactions of which they have been the
centers, there have come the newer breeds and the newer social types.
The great cities of the United States, for example, have drawn from the
isolation of their native villages great masses of the rural populations
of Europe and America. Under the shock of the new contacts the latent
energies of these primitive peoples have been released, and the subtler
processes of interaction have brought into existence not merely
vocational but temperamental types.

Transportation and communication have effected, among many other silent
but far-reaching changes, what I have called the "mobilization of the
individual man." They have multiplied the opportunities of the
individual man for contact and for association with his fellows, but
they have made these contacts and associations more transitory and less
stable. A very large part of the populations of great cities, including
those who make their homes in tenements and apartment houses, live much
as people do in some great hotel, meeting but not knowing one another.
The effect of this is to substitute fortuitous and casual relationship
for the more intimate and permanent associations of the smaller
community.

Under these circumstances the individual's status is determined to a
considerable degree by conventional signs--by fashion and "front"--and
the art of life is largely reduced to skating on thin surfaces and a
scrupulous study of style and manners.

Not only transportation and communication, but the segregation of the
urban population, tends to facilitate the mobility of the individual
man. The processes of segregation establish moral distances which make
the city a mosaic of little worlds which touch but do not
interpenetrate. This makes it possible for individuals to pass quickly
and easily from one moral milieu to another and encourages the
fascinating but dangerous experiment of living at the same time in
several different contiguous, perhaps, but widely separated worlds. All
this tends to give to city life a superficial and adventitious
character; it tends to complicate social relationships and to produce
new and divergent individual types. It introduces, at the same time, an
element of chance and adventure, which a