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Logical Fallacies

Examples and definitions of 10 common logical fallacies
by

Kim Steiner

on 18 March 2014

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Transcript of Logical Fallacies

Logical Fallacies
A statement that expresses your reasons
=
Weak Reasoning
Hasty Generalizations
Making an assumption about
a whole group based on an
inadequate sampling.
All librarians
are shy and smart.
Stereotypes
are based on hasty
generalizations.
All rich people are snobs
My friend said her English class is hard.
My English class is hard.
Therefore all English classes are hard.
Post h0c ergo propter hoc = False Cause
Latin for "after this, therefore because of this." People are prone to think that because one event follows another, the first event caused the next event.
Assumes that
B comes after A
so A caused B
When President Obama raised taxes,
the crime rate went up. Obama is
responsible for the rise in crime.
=
Slippery Slope
The arguer claims there will be a chain reaction that will end in some dire consequence, but there's really not enough evidence for that assumption.
Animal experimentation
reduces our respect for life.
If we don't respect life,
we are more likely to
tolerate violent acts like
murder.
Soon our society will
become a battlefield
where everyone will
constantly live in fear.
It will be the
end of civilization.
So, we need
to end animal
testing before it destroys humanity.
False Analogy
When the arguer compares
two things that aren't
really alike.
Guns are like hammers--
they're both metal tools with
metal parts that could be used
to kill someone. Therefore, we
should have restrictions on
purchasing hammers like we
do for guns.
Appeal to illegitimate authority
When the arguer tries to get the
audience to agree with them by
impressing them with a famous
name or authority figure, but not
necessarily an expert in the field.
The famous actor Matthew McConaughey,
who has played the role of a lawyer in many
Hollywood films, believes the death penalty
should be abolished.
So, the death
penalty is clearly
wrong.
Ad populum/Bandwagon
The Latin name means "to the people"
The arguer takes advantage of the desire
to have to be liked and fit in with others.
Gay marriages are
immoral because
70% of Americans
think so!
Ad hominem
The arguer discredits
the person rather than
the argument or the claim.
Andrea Dworkin has written
several books arguing about
the inequality of women in
the work place, but she is ugly
and bitter, so you shouldn't listen
to her.
Appeal to Pity
When an arguer tries to
get people to accept a
conclusion by making them
feel sorry for someone.
I did poorly
on the exam, but
you should give
me an A because
my cat has been sick,
my car broke down, and I've
had a cold, so it was really
hard for me to study.
Straw Man
When an arguer prevents a
wimpy version of the opponent's
position (counterarguments), and
tries to score points by knocking it
down. (Like knocking down a straw
man, it's not very impressive.)
Our society should help educate
the poor about social programs
designed to help them.

Handing the poor handouts
is not going to help. It's just
a waste of time and paper.
Most people do not read
handouts.

The arguer, partway through
an argument, goes off on a
tangent and raises a side
issue meant to distract the
audience from the original issue.
Red Herring
Grading this test on a
curve would be the fair
thing to do.

After all, classes go more
smoothly when the teacher
and the students get along
well.
Circular
Reasoning
The arguer keeps restating the same
idea without adding any new
information or arguments.
Euthanasia is morally acceptable.
It is a decent to help another human escape suffering through death.
Therefore, we need to stop
animal testing before it
destroys the world.
Special Pleading
having a double standard or asking
for an unjustified exception
Equivocation
changing the definition of a word in the
middle of the argument
Proof by Lack of Evidence
Appeal to tradition/
Appeal to high tech


Faulty Appeal to Authority
Show Seinfeld episode "The Doorman"
Also an example of equivocation
Circumstantial Ad Hominem
criticizing the background,
affiliations, or self-interest of
the arguer.
Play Seinfeld Video
entitled George and the
gymnast on youtube
Appeal to Fear
Either...Or (Bifurcation)
Only two options are offered when
there are actually alternatives to be
considered.
Equivocation
changing the meaning of a word in the
middle of an argument. (almost like a pun)
If the English don't drive on the right side
of the road, what are they doing on the wrong side?
Loaded Question/Begging the Question
When someone asks two questions, but one is hidden behind the other.
"Mr. Blanchard, what did you use to wipe your fingerprints off this gun?"
"I didn't use anything."
"You left your fingerprints on the gun, then?"
"I've never seen that gun."
"But you just said you never wiped your fingerprints off this gun."
Appeal to Ignorance
Because there is no
evidence to prove otherwise, it must be true.
How do you know God exists?
Because the Bible says so.
How do you know the Bible is accurate?
Because it is God's word.
Exigency
Immediate action is needed; urgency
For a limited time...
Call now...
The offer ends in 1 hour.
Transfer
Attempting to transfer the audience's emotions from one object to another.
Snob Appeal
Buy a product so you stand out from a crowd. A sense of exclusivity applies.
Appeal to Tradition
This is the way we have always done things, so it is the right way.
Full transcript