Once an argument is constructed using deductive reasoning, the author
needs to
determine how they will support their argument. Here are a few
acceptable
methods of evidence.
Experimentation: Experiments are exercises conducted in a controlled
environment to evaluate a hypothesis. For example, if someone wanted to
prove
that Drug X cured cancer, they would recruit two groups, give one group
the
drug, and another group a sham therapy. If the treated group showed
improvement, the author could then persuade his audience that the drug
was
effective.
Real Events: These are situations that have actually occurred either in
history
or in the realm of current events. For example, if someone wanted to
prove that
handguns are dangerous they might cite several events where children
were
accidentally shot in their homes.
Hypotheticals: These are situations that have not yet happened, but
could. For
example, if someone wanted to prove that the death penalty was immoral
they
could present a hypothetical situation where an innocent man was
wrongly
accused, sent to death row and executed.
Analogies: An analogy is when an author tries to convince his audience
that the
situation on which they are opining is similar to one where the desired
outcome
was achieved. For example, if someone wanted to prove that the failure
to
legalize gay marriage is a moral failure, they might draw an analogy to
the
period in American history where African Americans were not allowed to
marry
each other or to marry whites.
Authoritative Testimony: This is when a persuader cites a recognized
authority
in a field who supports their point of view. For example, if an author
is
trying to make a point about a matter of law they might quote a law
professor.
If the author was trying to make a point about religion, they might
quote a
member of the clergy.
Statistics: Statistics are a measurement typically expressed as a
percentage.
For example, if a persuader was trying to convince the reader that fast
food
leads to obesity they might cite a statistic that shows 80 percent of
Americans
who consumed fast food twice a week gained 20 extra pounds in a year.