constituent units would ever dream of
doing singly.[164] It becomes capable of deeds of heroism or of savage
cruelty. It will sacrifice itself or others with indifference. Above
all, the mere fact of moving in a mass gives the individual a sense of
power, a certainty of being in the right that he can--save under
exceptional circumstances--never acquire while alone. The intellect is
subdued, inhibition is inoperative, the instincts are given free play,
and their movement is determined in turn by suggestions not unlike those
with which a trained hypnotist influences his subject.

In the phenomena of contagion words and symbols play a powerful part.
They are both a rallying-point and an outlet for the emotions of a
crowd. These words or symbols may be wholly incongruous with the real
needs of a people, but provided they are sufficiently familiar they will
serve their purpose. And the more primitive the type of mind represented
by the mass of the people the more powerfully these symbols operate.
Shakespeare's portrayal of the crowd in _Julius Caesar_ remains eternally
true. The skilled orator, playing on old feelings, using familiar terms,
and invoking familiar ideas, finds a crowd quite plastic to his hands.
It is for these reasons that there is so keen a struggle with political
and social parties for a monopoly of good rallying cries, and a
readiness to fix objectionable titles on their opponents. Patriotism,
Little Englander, Jingo, The Church in Danger, Godless Education, etc.
etc. Causes are materially helped or injured by these means. There is
little or no consideration given to their justice or reasonableness; it
is the image aroused that does the work.

Psychological epidemics may in some cases be justly called normal in
character. That is, they depend upon factors that are always in
operation and which form a part of every social structure. A war fever
or a commercial panic falls under this head. In other instances they
depend upon abnormal conditions, upon the workings, perhaps, of some
obscure nervous disease, and are of a pathological description. In yet
other cases they represent a mixture of both. In such cases, for
example, as that of the Medieval Flagellants or of the Dancing Mania,
the presence of pathological elements is unmistakable. But neither of
these epidemics could have occurred without a certain social
preparation, and unless they had called into operation those principles
of crowd psychology to w