Review from Last Class
• The most used fallacy on Earth!
– Ad Hominem
• Confusing the quality of a person
making a claim with the quality of the
claim itself.
• Several Types of Ad Hominem
Fallacies
1. Personal Attack Ad Hominem
2. Inconsistency Ad Hominem
3. Circumstantial Ad Hominem
Fallacies
Typical Structure
• Person A makes claim X.
• Person B discredits Person A.
• Person B then concludes that claim X is false.
Fallacies
Ad Hominem Fallacies
#4. Special Type: Poisoning The Well
–Ad hominem in advance. Giving bad impression.
–Questioning the arguer before they even argue.
“Senator Clinton is going to give a talk tonight on
Iraq. Well, it’s just gonna be more baloney.
That gal will say anything to get a vote.”
“I don’t think Dave killed his wife.” - Even a
denial poisons the well.
“Dave owns a cat.” – does not poison the well.
Fallacies
Ad Hominem Fallacy
#5. Special Type: Positive Ad Hominem
Believing that if a person or group has positive
attributes then we have more reason to believe
their claims.
“He saved the children from the burning building. He
must be right when he says aliens attacked us.”
“The NRA is awesome. So, their proposals should all
be awesome too.”
Fallacies
Related to Ad Hominem Fallacy
#6. Genetic Fallacy
Rejecting an idea as false because it came from a
defective source: clubs, political parties, other
groups, etc. (not a specific individual)
“Does God exist? Of course not. That idea originated
with a bunch of ignorant people who knew nothing
about science.”
How is this different?
“John says God exists. What nonsense. He’s just
saying that because he works for a church.”
• Circumstantial ad hominem.
Fallacies
Ad Hominem
•Personal Attack
•Inconsistency
•Circumstantial
•Poisoning The Well
•Positive
Genetic
Group Exercise
In groups of 3 to 6
Complete Exercise 7-1: #2, 3, 5, 6, 9
2. Inconsistency ad hominem
3. Poisoning the well
5. Genetic fallacy
6. Inconsistency ad hominem
9. Circumstantial ad hominem
Fallacies
What’s wrong with this argument?
“Do I want the police department to take charge
of writing parking tickets? You mean, do I want to
get shot if I pull up next to a fire hydrant? What do
you think?”
Issue:
Should the police department to take charge of
writing parking tickets?
Conclusion:
No. Police departments shouldn’t….
Premise:
Because I don’t want to get shot if I pull up next to
a fire hydrant. (huh?)
Fallacies
#7. Straw Man Fallacy
• Distorting, oversimplifying, or
misrepresenting a claim so that it is easier
to refute.
“Do I want the police department to take
charge of writing parking tickets? You
mean, do I want to get shot if I pull up next
to a fire hydrant? What do you think?”
Fallacies
Where is the Straw Man Fallacy?
Fallacies
What’s wrong with this argument?
“Either we vote for a democratic president or the
country is going to go into the gutter.”
Issue:
Whether we should vote for a democratic
president.
Conclusion:
Yes. We should…
Premise:
I don’t want the country to go into the gutter.
Fallacies
#8. False Dilemma
• Limiting considerations to only two alternatives
although others may be available (either/or,
all/nothing, etc…)
“I don’t know why Barbara won’t go out with me. She
must think I’m too intense for her.”
•Special Types:
• Perfectionist Fallacy
• Line-Drawing Fallacy
Fallacies
Where is the False Dilemma?