Fallacies
A fallacy is an argument that contains a mistake in reasoning.
Types of Fallacies 2
Fallacies of Insufficient Evidence
Fallacies of Insufficient
Evidence
1. Hasty Generalization
2. Slippery Slope
3. Questionable Cause
4. Appeal to Ignorance
5. Appeal to Authority
6. Appeal to Tradition
Hasty Generalisations
The first baby I met cried the
whole time!
The second baby I met cried the
whole time!
The third baby I met cried
the whole time!
so
Babies cry
all the time!
Task Hasty Generalization
In your group complete these to make hasty generalizations:
1. Ahmed travels through Dhaid for the first time. He sees
10 people, all of them children. Ahmed returns to his town
and reports that ….
2. Jane, who has tattoos, stole my wallet. Therefore, all
people with tattoos…
3. I tried 2 Lebanese cheeses yesterday. They were both
salty. Lebanese cheese ...
This fallacy occurs when a general
conclusion is from a biased or
small sample. When we say
something always happens when
it might just happen sometimes.
Can you think of personal
examples of this?
Slippery Slope
Have you ever heard of people selling their
hair for other people to make wigs?
What could this have to do with cable TV?
http://www.youtube.com/watch?v=o36fkqYfa7c
What is the argument? What is the problem with it?
What’s the problem here?
If you don’t have
cable TV, you
won’t be able to
watch something
good, you will get
depressed, you
will go to a
seminar, you will
feel like a winner,
you will go to Las
Vegas, you will
lose everything
then you will sell
your hair to a wig
shop.
You don’t
want to sell
your hair to
a wig shop.
so…
You should
get cable TV.
What’s the problem here?
Going to the
mall is ok but
then you will
want to go out at
night, then you
might keep
secrets, then you
might do
something really
bad….
I don’t want
you to do
something
really bad.
so…
You can not
go to the
mall.
This fallacy occurs when we claim,
without enough evidence, that a
small or harmless action, will lead
to a terrible outcome.
Can you think of personal examples
of this?
Questionable Cause
Sometimes people see
connections between things that
don’t really exist.
What’s Ernie’s argument?
http://www.youtube.com/watch?v=u5xrr4RyqaE
What’s wrong with this
argument?
I put a
banana in
my ear.
There are
no
alligators
around.
so…
Bananas in
your ear
keep away
alligators.
What’s wrong with this
argument?
I drink a
lot of
green tea.
I don’t get
sick very
often.
so…
Green tea
stops
people
getting sick.
This fallacy occurs when someone
concludes that one thing causes
another simply because the two are
associated on a regular basis.
Can you think of personal examples
of this?
Appeal to Ignorance
Proof of a Yeti?
For hundreds of years, people
have said that large, hairy
monster called the Yeti lives in
the Himalayan mountains.
Some people call it Big Foot.
There is no scientific proof of
this claim.
What’s wrong with this
argument?
I don’t
know if
the Yeti
exists.
Nobody
can prove
it doesn’t
exist.
therefore…
The Yeti
exists.
The pattern for an appeal to
ignorance goes like this:
If A* was
true then I
would
know that
it was
true.
I do not
know if it
is true.
therefore…
A must be
false.
*Try using something instead of A here (something someone believes but you
don’t believe because you don’t have proof about e.g. Scientists say that there
is a new planet)
And it goes in reverse too.
If A* was
false then I
would
know that
it was
false.
I do not
know if it
is false.
therefore…
A must be
true.
*Try using something instead of A here (something someone believes but
you believe even though you don’t have proof about e.g. Camel milk cures cancer.
This fallacy occurs when the arguer
claims something is true because no
one has proven it false (or must be
false because no one has proven it
true).
Can you think of personal examples
of this?
Appeal to Authority
Which authority figures would
you listen to?
In what areas would you listen
to them?
Are they an expert in this field?
Is Justin Timberlake an expert
on cameras?
http://www.youtube.com/watch?v=CLsQbsDKMLs
What is this saying about Justin Timberlake?
What’s wrong with this argument?
I want to
buy the
best
camera I
can.
Justin
Timberlake
said the
Sony is the
best
camera.
so…
I should
buy a Sony
camera.
What’s wrong with this argument?
This fallacy occurs the arguer cites a
person who is not really an
authority on the subject. Therefore,
we can not trust the claim.
Can you think of personal examples
of this?
Appeal to Tradition
Have you ever heard of the
Running of the Bulls?
http://www.theguardian.com/world/video/2014/jul/14/pamplonarunning-bulls-four-injured-video
What’s wrong with this
argument?
It is our
tradition for
people to
run in the
streets in
front of
bulls.
Traditional
ways are
better than
modern
ways.
so…
We should
continue to
run with
the bulls.
What’s wrong with this
argument?
It is our
tradition for
boys to
carry
knives. They
have always
done this.
Traditional
ways are
better than
modern
ways.
so…
Boys should
carry
knives.
What’s wrong with this
argument?
For
hundreds of
years,
women did
not go out
to work.
Traditional
ways are
better than
modern
ways.
so…
Women
should not
go out to
work.
Can you make a fallacy for the
UAE using a tradition that has
changed with time?
?
?
so…
?
This fallacy occurs when it is
assumed that something is better
simply because it is older,
traditional, or it has "always has
been done.”
Can you think of personal examples
of this?
Do you remember them all?
Practice of Fallacies of
Insufficient Evidence
0 "The US shouldn't get involved militarily in other countries. Once
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the government sends in a few troops, it will then send in
thousands to die."
Women should stay home and take care of the children, because
they have filled these roles for centuries.
“My classmate said that psychology class was hard, and the one
I’m in is hard, too. All psychology classes must be hard!”
Since the class has no questions concerning the topics discussed
in class, the class is ready for a test.
My mother says you must drink 1 gallon of water per day. “Is she
a doctor?” “No, but she knows a lot about health.”
I’m not going to watch the football match. Whenever I watch, my
team loses.
Practice of Fallacies of
Insufficient Evidence
0 "The US shouldn't get involved militarily in other countries. Once the
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government sends in a few troops, it will then send in thousands to
die." Slippery Slope
Women should stay home and take care of the children, because they
have filled these roles for centuries. Appeal to Tradition
My classmate said that psychology class was hard, and the one I’m in
is hard, too. All psychology classes must be hard!” Hasty
Generalization
Since the class has no questions concerning the topics discussed in
class, the class is ready for a test. Appeal to Ignorance
My mother says you must drink 1 gallon water per day. “Is she a
doctor?” “No, but she knows a lot about health. “ Appeal to Authority
I’m not going to watch the football match. Whenever I watch, my
team loses. Questionable Cause
Additional Activities
More Practice
0 Choose 1 fallacy of insufficient evidence and find an
example (video or text).
0 Explain why it is a fallacy
0 What pattern is it following?
0 What value of critical thinking does it not display?
0 Explain how it could be improved
0 What would be a better way to write this argument?
0 Choose another fallacy
0 In groups, write a scenario to create a fallacious argument