Warm Up
NAME ONE ISSUE OR STORY
THAT YOU HEARD ABOUT IN
THE NEWS OVER THE
WEEKEND. WHAT FORM OF
MEDIA DID YOU HEAR THIS
FROM?
Logical Fallacies
HOW ARE WE PERSUADED BY THE MEDIA?
Logical Fallacies
A Logical Fallacy is…
A mistake in reasoning.
Types of Logical Fallacies
 Ad Hominem
 False Causality
 Red Herring
 Overgeneralization
 Bandwagon Effect
Ad Hominem
 Using a personal attack to disprove an argument.
 Types: name calling; irrelevant character issue; guilt
by association; false analogy.
 Example:
 You can't tell me I should quit smoking. You've never done
cancer research, so what would you know about it?
False Causality
 Because one thing follows another, it has caused the
other
 The cause identified is only part of the entire cause
 Example:
The only reason that Katy missed school was because
she is hanging out with the wrong crowd.
Red Herring
 Reasons have little relevance to the argument at
hand.
 Desperate arguers often try to change the ground
of the argument by changing the subject.
 Example:
 Winthrop should pave the lot behind Dinkins. Besides, I
can never find a parking space on campus anyway
Overgeneralization
 The argument draws a conclusion from a sample that
is too small and is made up of too few cases
 Example:
 In both of the murder mysteries I have read, the District
Attorney was the culprit. All mystery writers like to make
lawyers out to be villains."
Bandwagon Effect
 The main argument is that everyone is doing it and
everyone should join.
 Example:
 Fifty million Elvis fans can’t be wrong, I have to buy the CD!
Which Fallacy is being used?
1. "Affirmative action proponents accuse me of
opposing equal opportunity in the work force. I
think my positions on military expenditures,
education and public health speak for themselves."
2. "Despite the women's movement in the ‘70s,
women still do not receive equal pay for equal
work. Obviously, all such attempts to change the
status quo are doomed to failure."
Which Fallacy is it?
3. "Since Harvard, Stanford, and Berkeley have all
added a multicultural component to their
graduations requirements, Notre Dame should get
with the program.
4. Traditional historians appeal to the public's feeling
of nationalism just as the Nazis did.“
5. We must have a poltergeist in the house. When the
dog ran under the table the vase just seemed to
jump off the shelf all by itself.
Put this quote in your own words and explain
what it might mean to you.
 The most perfidious (deceitful)
manner of injuring a cause is to
vindicate (justify) it intentionally
with fallacious arguments.
-Friedrich Nietzsche
Using Logical Fallacies
(Not a good idea, but you should still know what they are)
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Should people participate in organ donation?
Should people of legal age vote in government elections?
Should we recycle?
Should we have the death penalty?
Should we be required to wear seat belts in cars?
Should people give blood?
Should people gamble?
Should we avoid junk food?
Choose a topic and use one of the logical fallacies to convince
your audience of your opinion.
Prepare a 30 second speech to persuade your audience.