is a powerful element
in making an argument persuasive, though the appeal that it makes to the
feelings of the readers is slight and subtle. In practice we mostly read
arguments either to help make up our minds on a subject or to get aid in
defending views for which we have no ready support. In the latter case
we do not need to be persuaded; but in the former there can be no
question that an argument which clears up the subject, and makes it
intelligible where before it was confusing, does have an effect on us
over and above its aid to our thought.

56. The Practical Interests of the Audience. Of directly persuasive
power, however, are the other two factors--the appeal to the practical
interests of readers, and the appeal to their emotions. Of these the
appeal to practical interests has no proper place in arguments on
questions of fact, but a large and entirely proper share in most
arguments of policy. Henry Ward Beecher's speech on the slavery issue in
the Civil War, before the cotton operatives of Liverpool,[60] is a
classic example of the direct appeal to the practical interests of an
audience. They were bitterly hostile to the North, because the supplies
of cotton had been cut off by the blockade; and after he had got a
hearing from them by appealing to the English sense of fair play, he
drove home the doctrine that a slave population made few customers for
the products of English mills. Then he passed on to the moral side of
the question.

Arguments on almost all public questions--direct election of senators,
direct primaries, commission form of government, tariff, currency,
control of corporations, or, in local matters, the size of a school
committee, the granting of franchises to street railroads or water
companies, the laying out of streets, the rules governing parks--are all
questions of policy in which the greatest practical advantage to the
greatest proportion of those who are interested is the controlling force
in the decision. At particular times and places moral questions may
enter into some of these questions, but ordinarily we come to them to
settle questions of practical advantage.

In arguments on all such questions, therefore, the direct appeal to the
practical interests of the people you are addressing is the chief factor
that makes for persuasiveness. Will a change to a commission form of
government make towards a reduction of taxes and towards giving greater
and more equitably distributed retur