Fallacies

Fallacious Reasoning (by Kylene Beers)

It’s Friday night and you want to go to a concert. You tell your parents or guardian that
everyone will be going, that it is supposed to be the safest concert that your city has
ever had, that if you don’t get to go, you won’t be invited to any parties for the rest of
your teenage years, and that if you parents trust you, they will let you go. Your parents
tell you that they think your argument is filled with fallacious reasoning. You aren’t sure
if that’s a compliment until you find out that fallacious reasoning means “false thinking.”
People reason fallaciously when they draw incorrect or false conclusions. Such
conclusions may be illogical, or they may be based on incomplete information.

For an argument to be convincing, it must be based on logic, or correct reasoning.
Opinions should be supported by reasons and evidence, such as facts, statistics,
examples, or expert testimony.

Fallacious or faulty reasoning can be hard to spot, so it’s important to watch for it
whenever you evaluate an argument.

Hasty

Generaliations -

Conclusions

drawn from weak

or insufficient

evidence

Your friend said

the concert

you’re attending

would have

extra security.

Obviously,
this will be the
safest concert
your city has
ever had.

False Cause & Effect -

Assuming that event A
caused event B simply
because A came first.

Going to concerts
will make me more
popular

Vestibulum cngue
tempus

Lorem ipsum dolor sit amet,
consectetur adipiscing elit,
sed do eiusmod tempor.

After I went to the
concert, I was
invited to a party.

Either/or Fallacy -

the assumption that a

problem or situation has
only one possible cause
or resolution when there

may be several.

If your parents
don’t let you to
go the concert,
then they don’t

trust you.

Stereotyping -

believing that all

members of a
group share a

certain

characteristic

​All concerts are unsafe!

Fallacious Reasoning (by Kylene Beers)

Your parents don't want you to go to the concert.

​Name-Calling

​They obviously don't know anything about anything!

​Edgar Allan Poe was a very, very disturbed man. Every single story and poem he ever wrote is about a disturbed

​In this selection, there are several types of fallacious reasoning, or arguments that are not logical. Answer the questions on the next slides about this.

Multiple Choice

"Every single story and poem he ever wrote is about disturbed, usually insane people." is a hasty generalization because

• probably hasn't read everything Poe wrote

• is not of Poe's generation

• someone once told the writer this

Multiple Choice

By implying that we shouldn't take Poe's stories seriously because he was always drunk, the writer is -

• name-calling

• using the either/or fallacy

• stereotyping

Multiple Choice

"The only way he could have known is by being insane himself" is another hasty generalization because

• the statement assumes we all agree on something

• everyone knows what it is like to be insane

• there is insufficient evidence to support the statement

Multiple Choice

By saying that Poe's use of dashes and exclamation points suggests that a very nervous person or someone on drugs wrote the text, the writer is -

• name-calling

• making a hasty generalization

• using false cause and effect

Open Ended

Practice recognizing different types of fallacious reasoning by completing the following statement:

Hasty Generalization: She would not loan me a pencil. Everyone obviously...

Open Ended

Practice recognizing different types of fallacious reasoning by completing the following statement:

False cause and effect: After I used this new toothpaste, I got invited to a party. This new toothpaste is...

Open Ended

Practice recognizing different types of fallacious reasoning by completing the following statement:

Either/or fallacy: If we don't elect a girl for class president, then girls...

Open Ended

Practice recognizing different types of fallacious reasoning by completing the following statement:

Stereotyping: All teenagers are...

Open Ended

Practice recognizing different types of fallacious reasoning by completing the following statement:

Name-calling: Ray's in favor of school uniforms. That's no surprise because Ray...