LUCAS. Chapter 16: Methods of Persuasion
Chapter Objectives
1.
Explain the role of speaker credibility in persuasive speaking.
2.
Define the differences among initial credibility, derived credibility, and terminal
credibility.
3.
Discuss three ways a speaker can enhance her or his credibility during a persuasive speech.
4.
Explain why it is important for persuasive speakers to use evidence in their speeches.
5.
Discuss the four tips presented in the chapter for using evidence in persuasive speeches.
6.
Define reasoning from specific instances and explain the guidelines given in the chapter for
using this method of reasoning.
7.
Define reasoning from principle and explain the guidelines a speaker should follow when
employing reasoning from principle.
8.
9.
Define causal reasoning and explain the two common errors speakers need to avoid when
using causal reasoning.
Define analogical reasoning and explain how to judge the validity of an analogy.
10.
Identify the red herring, ad hominem, either-or, bandwagon, and slippery slope fallacies.
11.
Explain the role of emotional appeal in persuasive speaking and discuss when it is ethical
for a speaker to employ emotional appeal.
12.
Identify three methods a speaker can use to generate emotional appeal when speaking to
persuade.
16. Chapter Outline
I.
There is a perpetual interest in the methods of persuasion
A. People have been studying the strategies and tactics of successful persuasion for
thousands of years.
B. Scholars generally agree that listeners are persuaded by a speaker for one or more of
four reasons.
1.
Because they perceive the speaker as having high credibility.
2.
Because they are won over by the speaker’s evidence.
3.
Because they are convinced by the speaker’s reasoning.
4.
Because their emotions are touched by the speaker’s ideas or language.
II.
A speaker’s credibility plays an important role in persuading the audience
A. Credibility is the audience’s attitude toward or perception of the speaker.
1.
The more favorably listeners view a speaker, the more likely they are to accept
what the speaker says.
2.
A speaker’s credibility will vary from audience to audience and topic to topic.
a.
The same speaker may have high credibility for one audience and low
credibility for another.
b.
A speaker may also have high credibility on one topic and low credibility
on another.
B. A speaker’s credibility is affected by two primary factors—competence and
character.
1.
Competence refers to how an audience regards a speaker’s intelligence,
expertise, and knowledge of the subject.
2.
Character refers to how an audience regards a speaker’s sincerity,
trustworthiness, and concern for the well-being of the audience.
C. There are three types of credibility.
1.
Initial credibility is the audience’s perception of the speaker before the speech
begins.
2.
Derived credibility is produced by everything a speaker says and does during
the speech.
3.
Terminal credibility is the audience’s perception of the speaker at the end of the
speech.
D. There are three strategies speakers can use to enhance their credibility.
1.
Speakers can enhance their credibility by explaining their competence.
a.
They can stress their research on the speech topic.
b.
They can stress special knowledge of the topic gained through personal
experience.
2.
Speakers can enhance their credibility by establishing common ground with the
audience.
a.
Establishing common ground means showing respect for and identifying
with the audience’s values and beliefs.
b.
Establishing common ground is especially important in the introduction of
a persuasive speech.
3.
III.
Speakers can enhance their credibility by delivering their speeches fluently,
expressively, and with conviction.
a.
There is substantial research showing that fluent, animated delivery
greatly enhances a speaker’s credibility.
b.
Speaking with genuine conviction also does a great deal to strengthen a
speaker’s credibility.
A speaker’s use of evidence plays an important role in persuading the audience
A. Evidence consists of examples, statistics, and testimony used to prove or disprove
something.
B. To be persuasive, speakers must support their views with evidence.
1.
Careful listeners are skeptical of unsupported claims and generalizations.
2.
Strong evidence is particularly important when the speaker is not recognized as
an expert on the speech topic.
3.
Strong evidence is also crucial when the target audience opposes the speaker’s
point of view.
a.
Skeptical listeners will mentally create counterarguments to answer what
the speaker says.
b.
The speaker’s success will depend partly on how well she or he anticipates
these internal responses and gives evidence to refute them.
C. There are four tips persuasive speakers should follow to use evidence effectively.
1.
Persuasive speakers should use specific evidence.
a.
Research indicates that evidence is more persuasive when it is stated in
specific rather than general terms.
b.
Specific evidence also enhances a speaker’s credibility by demonstrating his
or her grasp of the topic.
2.
Persuasive speakers should use novel evidence.
a.
Studies show that evidence will be more persuasive when it is new to the
audience.
b.
Presenting an audience new facts and figures requires resourceful
research, but it is well worth the effort.
3.
Persuasive speakers should use evidence from credible sources.
a.
There is a good deal of research indicating that listeners find evidence
from competent, credible sources more persuasive than evidence from less
qualified sources.
b.
Listeners are especially skeptical about evidence from sources that appear
to be biased or self-interested.
4.
Persuasive speakers should make clear the point of their evidence.
a.
Studies have shown that speakers cannot count on listeners to draw, on
their own, the conclusion a speaker wants them to reach.
b.
In most situations, persuasive speakers need to be sure to state the point
they are trying to make with their evidence.
IV. A speaker’s reasoning plays an important role in persuading the audience
A. Reasoning is the process of drawing a conclusion based on evidence.
B. Public speakers have two major concerns with respect to reasoning.
1.
The first is to make sure the speaker’s reasoning is sound.
2.
The second is to get listeners to agree with the speaker’s reasoning.
C. Persuasive speakers often use reasoning from specific instances.
1.
When speakers reason from specific instances, they progress from a number of
particular facts to a general conclusion.
2.
Speakers should follow three guidelines when reasoning from specific
instances.
a.
They need to beware of hasty generalizations based on insufficient
evidence.
b.
They need to be careful with their wording so as not to overstate the facts.
c.
They need to reinforce their argument with statistics or testimony.
D. Persuasive speakers often use reasoning from principle.
1.
When speakers reason from principle, they move from a general principle to a
specific conclusion.
2.
Speakers should follow two basic guidelines when reasoning from principle.
a.
They need to make certain the audience will accept the general principle.
b.
They also need to make sure the audience will accept the minor premise.
E. Persuasive speakers often use causal reasoning.
1.
Causal reasoning tries to establish the relationship between causes and effects.
2.
Speakers should follow two guidelines when using causal reasoning.
a.
They should avoid the fallacy of false cause.
(1) This fallacy is often known by its Latin name, post hoc, ergo propter
hoc, which means “after this, therefore because of this.”
(2) Speakers who commit this fallacy assume that because one event
comes after another, the first event must necessarily be the cause of
the second.
b.
Speakers should also avoid the fallacy of assuming that events have only
one cause.
(1) Most events have several causes.
(2) Speakers need to be wary of oversimplifying complex causes or
attributing a complex effect to a single cause.
F. Persuasive speakers often use analogical reasoning.
1.
Analogical reasoning compares two similar cases to draw the conclusion that
what is true in one case will also be true in the other.
2.
The most important guideline for speakers using analogical reasoning is to make
sure the two cases being compared are essentially alike.
a.
If the cases being compared are essentially alike, the analogy is valid.
b.
If the cases being compared are not essentially alike, the analogy is invalid.
G. Regardless of the method of reasoning they use, speakers must guard against logical
fallacies in their presentations.
1.
Three of those fallacies, as we saw earlier, are hasty generalization, false cause,
and invalid analogy.
2.
V.
Five additional fallacies are discussed here.
a.
The red herring fallacy introduces an irrelevant issue in order to divert
attention from the subject under discussion.
b.
The ad hominem fallacy substitutes an attack on the person for discussion
of the real issue in dispute.
c.
The either-or fallacy, sometimes referred to as a false dilemma, forces
listeners to choose between two alternatives when more than two
alternatives exist.
d.
The bandwagon fallacy assumes that because something is popular, it is
therefore good, correct, or desirable.
e.
The slippery slope fallacy assumes that taking a first step will lead
inevitably to a second step and so on down the slope to disaster.
A speaker’s emotional appeals play an important role in persuading the audience
A. Emotional appeals—often called motivational appeals—are intended to make
listeners feel sad, angry, guilty, fearful, reverent, or the like.
B. Effective persuasion often requires emotional appeal.
1.
Few people are moved to change their attitudes or take action when they are
bored or complacent.
2.
As George Campbell wrote in his Philosophy of Rhetoric, “When persuasion is
the end, passion also must be engaged.”
C. Speakers can generate emotional appeal in three ways.
1.
One way to generate emotional appeal is with emotionally charged language.
a.
Language can generate strong responses in an audience by evoking
emotions attached to particular words and phrases.
b.
Speakers should be careful, however, of calling attention to their
emotional appeals with a sudden barrage of emotional language that is
inconsistent with the rest of the speech.
2.
A second way to generate emotional appeal is with vivid examples.
a.
Vivid, richly textured examples allow emotional appeal to grow naturally
out of the content of the speech.
b.
Examples add impact, bring ideas home to listeners in personal terms, and
make the speech more compelling.
3.
A third way to generate emotional appeal is to speak with sincerity and
conviction.
a.
The strongest source of emotional appeal is the conviction and sincerity of
the speaker.
b.
Speakers who feel the emotion themselves will communicate that emotion
through everything they say and do in the speech.
D. Because emotional appeals have so much potential power, they need to be used with a
strong sense of ethical responsibility.
1.
Emotional appeals can be abused by unscrupulous speakers for detestable
causes.
2.
Emotional appeals can also be used by principled speakers for noble causes.
3.
Ethical speakers make sure their emotional appeals are appropriate to the speech
topic.
a.
4.
5.
Emotional appeals are often necessary when a speaker is trying to
persuade an audience to take action.
b.
Emotional appeals are usually inappropriate when a speaker is discussing
a question of fact.
Even when trying to move listeners to action, a speaker should never substitute
emotional appeals for evidence and reasoning.
a.
Persuasive speeches should always be built on a firm foundation of facts
and logic.
b.
Speakers need to develop a good case based on reason and kindle the
emotions of the audience.
When using emotional appeals, persuasive speakers should also keep in mind
the guidelines for ethical speechmaking discussed in Chapter 2.