Transcript Logical Fallacies: How to spot poor arguments

Logical Fallacies:
How to spot poor arguments
EQ: WHAT MAKES SOMETHING PERSUASIVE?
STANDARD: ELAW2.2 PERSUASIVE WRITING
 Last class we talked about logical appeals,
emotional appeals, and ethical appeals. Who
can tell me what they are?
 Logical appeals= logos
 Emotional appeals= pathos
 Ethical appeals= ethos
 When a speaker/writer uses ethos, pathos, or logos,
he/she may also use a logical fallacy intentionally
or not.
 Logical fallacies are illogical statements someone
uses in an argument.
 They can be sneaky, so watch out for them!
Group 1
Double Talk
 Definition: nonsense, rambling, ambiguity, or
elaboration of the obvious
 Example: The cat, which is a domesticated version of
wild felines, is feline-like.
 This is double talk because it only repeats what a cat
is, which everyone already knows. It elaborates on
the obvious and doesn’t really prove anything.
Complex Question
 Definition: asking a question containing one or more
unproven assumptions and expecting a simple
answer.
 Example: Why are you so lazy?
 This is a complex question because it assumes the
other person is lazy even though nothing has been
proven. Also, there may be many reasons why a
person is appears to be lazy, so a simple answer
won’t work!
False Analogy
 Definition: A comparison of things that should not
be used because they differ too much or a
comparison that is made in an unfair way.
 Example: Guns are like hammers--they're both
tools with metal parts that could be used to kill
someone, yet it would be ridiculous to restrict the
purchase of hammers. Therefore, restrictions on
purchasing guns are equally ridiculous.
 While guns and hammers do share certain
features, these similarities are not the ones at stake
in deciding whether to restrict guns.
Oversimplification
 Definition: Based on too little evidence or evidence
that ignores exceptions
 Example: My math test was hard, and my Spanish
test was hard. Therefore, all tests are hard.
This is an overgeneralization because it ignores the
fact that some tests are not hard and all people may
not feel the same way the speaker does.
Question Begging
 Definition: Assuming that you have already proven what
you set out to prove or using a statement to prove itself.
 Example: Euthanasia is morally acceptable. It is a
decent, ethical thing to help another human being
escape suffering through death.
 The arguer has really just said the same thing twice:
"decent, ethical" means pretty much the same thing as
"morally acceptable," and "help another human being
escape suffering through death" means "euthanasia."
The arguer hasn't yet given us any real reasons why
euthanasia is acceptable.
Argument Ad Hominem
 Definition: attacking a person associated with the
issue instead of the issue itself
 Example: Kenny Powers would make a bad governor
because he cheated on his girlfriend.
Regardless of what Mr. Powers does, attacking his
personal mistakes has nothing to do with his abilities
as a governor.
Group 2
Bandwagon Effect
(Also called appeal to popularity)
 Definition: Encourages listeners to act or think a
certain way because everyone else is
 Example: The student council, the football team, and
the cheerleaders all think the dress code should
change. You should too.
Just because a lot of people agree on the dress code
does not mean that their opinions are correct or that
the listener should agree with them.
Atmosphere Effect
 Definition: A false statement is assumed to be true
just because it is introduced along with true
statements.
 Example: If you want to save money, look cool, and
wear brand-name fashion, then shop at Macy’s!
 This statement doesn’t tell whether or not Macy’s
will actually save you money, make you look cool, or
sells brand-name fashion.
Guilt by Association
 Definition: Someone’s qualities are assumed based
on the people that person associates with
 Example: Ariel hangs out with the lazy students, so
she must be lazy too.
 This doesn’t prove what Ariel is like at all. It only
shows who her friends are.
Poisoning the Well
 Definition: evidence is disallowed because its source
is questionable.
 Example: That can’t be true if you read it in Star
Magazine.
 This isn’t fair because even though Star Magazine
can print many untrue things, it doesn’t mean that
everything it prints is a lie.
Hypothesis Contrary to Fact
 Definition: When someone starts speculating from a
false assumption.
 Example: If you had done your homework, you
would have passed the test.
 While it is reasonable to say that doing the
homework would have helped, it does not mean that
the student would have automatically passed the
test.
Confusing What Should Be with What Is
 Definition: Desire is confused with reality
 Example: My wallet isn’t lost; I saw it here yesterday!
 Even though your wallet was in a certain place a day
ago, it does not mean that it will be in the same place
again today. You wish your wallet were in the same
spot, but it isn’t.
Now
 You will read the following persuasive texts from the
American Revolution:
 Read the excerpt from The Crisis by Thomas Paine
(p.87-91)
 Read the excerpt from The Declaration of
Independence by Thomas Jefferson (p.97-103)
 There will be a quiz and class work over these
selections next class, so read thoroughly!
*See if you can find any logical fallacies in either of
these texts as you read!