1. Common Mistakes in Weak Arguments
LOGICAL FALLACIES
Common Mistakes in Weak Arguments
Roberts
AP Language and Composition

2. Definition
Logical fallacies are flaws in reasoning that lead to faulty, illogical statements. They are unreasonable argumentative tactics named for what has gone wrong during the reasoning process. In other words, they are potential vulnerabilities or weaknesses in an argument.

3. Most logical fallacies masquerade as reasonable statements, but they are in fact attempts to manipulate readers by reaching their emotions instead of their intellects.

4. Introduction Ad Hominem Straw Man Hasty Generalization False Dilemma
Circular Reasoning
Begging the Question
Post Hoc
Appeal to False Authority
Bandwagon
Either/Or
False Analogy

5. Ad Hominem (fallacy of relevance)
Latin for against the man
Directly attacks someone’s appearance, personal habits, or character rather than focusing on the merit of the issue at hand. The implication is that if something is wrong with this person, whatever he/she says must be wrong.
How can you say he’s a good musician when he’s been in and out of rehab for three years?

6. Ad Hominem – Making it Personal
Sara is divorced, so whatever relationship advice she gives you can’t be good.
It is the suggestions, not the person who makes them that deserve attention. Sara’s marital status has nothing to do with the quality of her advice. Isn’t it also possible that Sara could be married and give awful advice?
If my husband forgot to wash his dish, I would move out too. You did the right thing, Carol.

7. Straw Man Fallacy (fallacy of accuracy)
Straw Man Fallacy occurs when a speaker chooses a deliberately poor or oversimplified example in order to ridicule and refute an opponent’s viewpoint.
Politician X proposes we put astronauts on Mars in the next four years. Politician Y ridicules this proposal by saying that his opponent is just looking for “little green men.”

8. Hasty Generalization (fallacy of insufficiency)
A hasty generalization is a conclusion based on insufficient or unrepresentative evidence.
Stereotyping and Sexism are forms of this fallacy. Take, for example common dumb blonde jokes:
Q: What do you call a blonde skeleton
in the closet?
A: Last year's hide-and-go-seek winner.

9. Example of a Generalization
The only redheads I know are rude.
Therefore, all redheads must have bad
manners.
If the speaker only knows two redheads, then he has insufficient evidence to make the general claim about all people with that hair color.

10. Circular Reasoning (fallacy of insufficiency)
Circular Reasoning involves repeating the claim as a way to provide evidence resulting in no evidence at all.
“You can’t give me a C! I’m an A student!”
“Shop at this store because it’s a shopper’s
paradise.”
“Buy this shampoo. It’s the best shampoo you’ll
ever use.”

11. Begging the Question
This is a kind of circular argument where the support only restates the claim.
Wrestling is dangerous because it is unsafe.
Jogging is fun because it is enjoyable.
Unsafe means the same thing as dangerous and fun means the same thing as enjoyable. This makes the reasoning circular.

12. Post Hoc Fallacy Short for post hoc, ergo propter hoc,
which means after this, therefore caused
by this.
This fallacy assumes that just because B
happened after A, it must have been caused
by A.
Politicians love this one.

13. Post Hoc Example
Since Governor Bush took office, unemployment of minorities in the state has decreased by seven percent. Governor Bush should be applauded for reducing unemployment among minorities.
Before we pat the governor on the back, the speaker must show that Bush’s policies are responsible for the decrease in unemployment. It is not enough to show the decrease came after his election.

14. Appeal to False Authority
Appeal to False Authority occurs when someone who has no expertise to speak on an issue is cited as an authority.
“I’m not a doctor, but I play one on T.V.”

15. Bandwagon Appeal
Bandwagon Appeal, Ad Populum fallacy, occurs when evidence boils down to “everybody’s doing it, so it must be a good thing to do.”
“You should vote to elect Rachel Johnson – she has a strong lead in the polls!”

16. Either – Or / False Dilemma
A false dilemma asserts that a complex situation can have only two possible outcomes and that one of the options is necessary or preferable.
Either go to college or forget about making money.
This falsely implies that a college education is a pre-requisite for financial success.
Was it her college education that made Britney tons of money?

17. False Analogy Example can’t we find the cure for the common cold?
If we can put a man on the moon, why
can’t we find the cure for the common
cold?
While both things being compared here are related to science, there are more differences than similarities between space and biological advancements.

18. False Analogy
An analogy points out similarities in things that are otherwise different. A false analogy claims comparison when differences outweigh similarities. Essentially, it’s comparing apples and oranges!

19. Summary Ad Hominem Straw Man Hasty Generalization False Dilemma
Circular Reasoning
Begging the Question
Post Hoc
Appeal to False Authority
Bandwagon
Either/Or
False Analogy

20. Sources Used Troyka, Lynn Quitman. Quick Access. New
Jersey: Prentice Hall,
Shea, Renee H. The Language of Composition. New York: Bedford/St. Martin’s, 2013.