relation of blushing and laughter to social control, as an evidence of
the emotional dependence of the person upon the group, is at its apogee
in adolescence.

Interaction through sensory impressions and emotional expression is
restricted to the communication of attitudes and feelings. The
selections under the heading "Language and the Communication of Ideas"
bring out the uniquely human character of speech. Concepts, as Max
Mueller insists, are the common symbols wrought out in social experience.
They are more or less conventionalized, objective, and intelligible
symbols that have been defined in terms of a common experience or, as
the logicians say, of a universe of discourse. Every group has its own
universe of discourse. In short, to use Durkheim's phrase, concepts are
"collective representations."

History has been variously conceived in terms of great events,
epoch-making personalities, social movements, and cultural changes. From
the point of view of sociology social evolution might profitably be
studied in its relation to the development and perfection of the means
and technique of communication. How revolutionary was the transition
from word of mouth and memory to written records! The beginnings of
ancient civilization with its five independent centers in Egypt, the
Euphrates River Valley, China, Mexico, and Peru appear to be
inextricably bound up with the change from pictographs to writing, that
is to say from symbols representing words to symbols representing
sounds. The modern period began with the invention of printing and the
printing press. As books became the possession of the common man the
foundation was laid for experiments in democracy. From the sociological
standpoint the book is an organized objective mind whose thoughts are
accessible to all. The role of the book in social life has long been
recognized but not fully appreciated. The Christian church, to be sure,
regards the Bible as the word of God. The army does not question the
infallibility of the Manual of Arms. Our written Constitution has been
termed "the ark of the covenant." The orthodox Socialist appeals in
unquestioning faith to the ponderous tomes of Marx.

World-society of today, which depends upon the almost instantaneous
communication of events and opinion around the world, rests upon the
invention of telegraphy and the laying of the great ocean cables.
Wireless telegraphy and radio have only perfected these earlier means
and re