Transcript Slide 1

Persuasion
& Reasoning
Chapter 18
1
Logos

The logical arrangement of
evidence in a speech
2
Ethos

Refers to the speaker’s
credibility
3
Pathos

Refers to the emotional
appeals made by a speaker
4
Effective Use of Evidence
Use of specific evidence
 Novel information
 Credible sources

Persuasive Speech – use of evidence
by Jessica Fuller
(partial: 12 sec.)
Click image to play video; “alt” &
“enter” keys for full screen.
Windows Media Player required
5
Credibility
In research:
the potential bias of a
source
 In reasoning:
the trustworthiness of the
source

6
Using Credible Sources
Persuasively
Provide enough information
about source so audience
can assess credibility
 Select sources audience will
see as trustworthy & fair

7
Credibility

Comes from audience’s
perception of speaker’s
competence & character
Check Web Link 18.1:
Credible Internet Sites at
the Invitation to Public Speaking website.
8
Competence

Audience’s view of
speaker’s intelligence,
expertise, & knowledge of
a subject
9
Character

Audience’s view of
speaker’s sincerity,
trustworthiness & concern
for the well-being of the
audience
10
Types of Credibility

Initial credibility

Derived credibility

Terminal credibility
11
Enhancing Your
Credibility
Explain your competence
as you begin your speech
 Establish common ground
with audience
 Deliver speech fluently,
with expression &
conviction

12
Appeals to Emotions to:
Gain attention & motivate
listening
 Reinforce points
 Express personal
commitment
 Call to action or conclude
memorably

13
Effective Use of
Emotional Appeals

Stay audience centered

Use vivid language

Balance emotion & reason
14
Errors Using
Emotional Appeals
Overly graphic or violent
appeals
 Overly frightening or
threatening appeals
 Overly manipulative
appeals

15
Mythos

Interrelated set of beliefs,
attitudes, values & feelings
held by members of a
particular society or
culture
16
Fallacy

An argument that seems
valid but is flawed because
of unsound evidence or
reasoning
Complete Interactive Activity 18.1:
Identifying Fallacies at the
Invitation to Public Speaking website.
17
Types of Fallacies
Ad Hominem
 Bandwagon
 Either-Or
 Red Herring
 Slippery Slope

18