PERSUASION AND
LOGICAL FALLACIES
What are they and HOW do you avoid them?
PATHOS, ETHOS, AND
LOGOS
 Quick review!
Pathos: appeal to emotion.
Ethos: appeal using author’s credibility or background
Logos: appeal to the audience’s logic and reasoning
Sometimes, these forms of persuasion can lead to logical fallacies
which is another way to say “flawed argument”.
HASTY GENERALIZATION
 Also called “Leaping to Conclusions”
 This fallacy occurs when a conclusion is reached with too little
supporting information.
 I.E., Two weightlifters I know take steroids, that means that ALL
weightlifters take steroids.
 Your claim should be supported by valid data. Too small sample sizes,
and stereotypes are NOT valid source data.
HASTY GENERALIZATIONS
 https://www.youtube.com/watch?v=pem_FwggPsM
SLIPPERY SLOPE
 This fallacy occurs when one event happens and the speaker or writer
assumes a chain of events occurring because of the one inciting incident.
These are usually negative.
 “We have to stop the tuition increases! Next thing you know they’ll be
charging $40K a semester!”
 This is illogical because there’s no way to know all the variables that
lead to this conclusion. It is better to keep cause and effect to relatable
information and supported arguments.
SLIPPERY SLOPE
 https://www.youtube.com/watch?v=iFSKH7Gmni8
CIRCULAR REASONING
 This fallacy occurs when your supporting argument and claim are the
same. Thereby, echoing each other and offering no new information.
 FOR EXAMPLE:
 Pvt. Joe Bowers: What are these electrolytes? Do you even know?
 Secretary of State: They're... what they use to make Brawndo!
 Pvt. Joe Bowers: But why do they use them to make Brawndo?
 Secretary of Defense: [raises hand after a pause] Because Brawndo's got
electrolytes. (Idiocracy, movie)
RED HERRING
 This fallacy occurs when one point is being argued and another
non-related (but seemingly related) point is brought up to lead the
argument down a different path, away from the original point.
 "I think there is great merit in making the requirements stricter for
the graduate students. I recommend that you support it, too. After all,
we are in a budget crisis and we do not want our salaries affected."
GUILT BY ASSOCIATION
 This is easily defined. Someone is considered guilty by their mere
association with a (presumed) guilty party.
 Tybalt hates Montagues, and Romeo is a Montague. Therefore
Romeo is a no good, rotten scoundrel that must be killed.
AD HOMINEM
 Literally “against the man”-this is an attack on the person. It takes
three forms:
• Abusive: an attack on the personal or character traits of the opposition
• Circumstantial: irrelevant personal circumstances of the person making
the argument are used to distract attention from the argument and used as
evidence against it.
• Tu quoque: this argues that the argument is irrelevant because the speaker
does not “practice what they preach”.
 Attacking the person rather their views shows a lack of preparation
and thoughtfulness on the speaker’s part.
YOUR TURN
 In your group, talk about these questions:
 Why should headphones be allowed?
 Should the school have the right enforce dress code?
 Should high school start later in the day?
 Should employers be allowed to use social media to determine eligibility for hire?
 Should marijuana be legalized in Texas?
 Try to make an argument, and avoid these fallacies.