erate some of those forces which exercise such
a powerful influence on society.

First, let us take the force of _Public Opinion_, which seems to
exercise a relentless sway over the minds and manners of men. This is a
very subtle and secret force, which is most difficult to trace, and
resembles electricity in the science of physics. We cannot see it, but
are only able to judge of its power by its results. Its point of
application is not in the individual, but in the collection of
individuals who make up the social system; and it is, in reality, the
resultant of, or the compromise between, the various elementary forces
which make up human society. Yes, compromise is a purely mechanical
affair, based on the principle of the parallelogram of forces; and as
public opinion is the result of a compromise, we may calculate its
force. For example: 'It is required to know the state of public opinion
in the matter of politics, when the results of a General Election show
that the Conservatives are to the Liberals as 10 : 9.'

Let OC be the direction of the Conservative force.

Let OL be that of the Liberal.

Then by _data_ OC : OL :: 10 : 9.

[Illustration]

Complete the parallelogram, and join OP.

Then OP represents the force of public opinion in magnitude and
direction.

N.B.--The direction of OL is determined by the amount of deviation of
the policy of the Liberals from that of the Conservatives.

As in physical, so in social science, impulsive forces sometimes act,
and effectually disturb our system and our calculations. Public opinion
is very liable to the action of disturbing forces. Panic is an impulsive
force, which defies the power of the most learned professors of social
science to determine its magnitude and direction. Some strange
unforeseen catastrophe--the fascination caused by a brilliant and
unscrupulous orator, a cruel wrong, a blind revenge for real or
imaginary injustice--will sometimes rouse one element of passion latent
in the vast body of public opinion; so that it breaks with all that
hitherto restrained and balanced it, and precipitates society into a
course of conduct inconsistent with its former behaviour, and bloodshed,
revolution, the breaking-up of laws, are the terrible results of panic
or revengeful passion.

Society is, as it were, split up by the terrible action of such
impulsive forces, just as wood is split up by the repeated blows of the
hatchet. It is, therefore, the duty of states