Fallacies.ppt

Zaid Ali Alsagoff
zaid.alsagoff@gmail.com
Module 4:
Fallacies

Man or Woman?
Source: http://www.coolopticalillusions.com/manwoman.htm

How many legs does this elephant have?
Source: http://www.coolopticalillusions.com/elephantlegs.htm

Which officer is the tallest?
Source: http://www.coolopticalillusions.com/optical_illusions_images_2/giant_man.htm

Is this wave moving?
Source: http://www.grand-illusions.com/opticalillusions/oblong_wave/

AirAsia +
Girls = Fun
Analyze
+
Evaluate
=
Your Opinion?
Target Audience?

Module 4: Fallacies
1. Fallacies
of Relevance
2. Fallacies of
Insufficient
Evidence
What
mistake!!!

4.0 What is a Fallacy?
A (logical) fallacy is an argument that contains a
mistake in reasoning.
Fallacies can be divided into two general types:
 Fallacies of Relevance
Arguments in which the premises are logically
irrelevant to the conclusion.
 Fallacies of Insufficient Evidence
Arguments in which the premises, though
logically relevant to the conclusion, fail to provide
sufficient evidence for the conclusion.

“There is nothing so stupid as an educated man,
if you get him off the thing he was educated in”
- Will Rogers

4.1 Fallacies of Relevance
A statement is RELEVANT to another statement if it
provides at least some reason for thinking that the second
statement is true or false.
There are three ways in which a statement can be relevant
or irrelevant to another:
 A statement is positively relevant to another statement if it provides
at least some reason for thinking that the second statement is true.
 A statement is negatively relevant to another statement if it
provides at least some reason for thinking that the second statement
is false.
 A statement is logically irrelevant to another statement if it provides
no reason for thinking that the second statement is either true or
false.

4.1 Fallacies of Relevance
Personal Attack Appeal to Pity
Attacking the Motive Bandwagon
Argument
Look Who’s Talking Straw Man
Begging the Question Red Herring
Scare Tactics Equivocation
Two Wrongs Make a Right

4.1.1 Personal Attack
Example:
Professor Doogie has argued for more emphasis on music in
our F2F classes to facilitate creativity. But Doogie is a
selfish bigheaded fool. I absolutely refuse to listen to him.
Personal Attack
When an arguer rejects a person’s argument or claim
by attacking the person’s character rather than
examining the worth of the argument or claim itself.
1. X is a bad person.
2. Therefore X's argument must be bad.
Pattern

4.1.2 Attacking the Motive
Example:
Donald Trump has argued that we need to build a new campus. But Trump
is the owner of Trump’s Construction Company. He’ll make a fortune if
his company is picked to build the new campus. Obviously, Trump’s
argument is a lot of self-serving nonsense.
Attacking the Motive
When an arguer criticizes a person’s motivation for
offering a particular argument or claim, rather than
examining the worth of the argument or claim itself.
1. X has biased or has questionable motives.
2. Therefore, X’s arguments or claim should be rejected.
Pattern

4.1.3 Look Who’s Talking
Example:
Doctor: You should quite smoking.
Patient: Look who’s talking! I’ll quit when you do, Dr. Smokestack!
Look Who’s Talking (tu quoque)
When an arguer rejects another person’s argument
or claim because that person is a hypocrite.
1. X fails to follow his or her own advice.
2. Therefore, X’s claim or argument should be rejected.
Pattern

4.1.4 Two Wrongs Make a Right
Examples:
1. “I don’t feel guilty about cheating on Zaid’s online quiz. Half the
class cheats on his quiz.”
2. “Why pick on me, officer? Everyone else is using drugs.”
Two Wrongs Make a Right
When an arguer attempts to justify a wrongful act
by claiming that some other act is just as bad or worse.
1. Others are committing worse or equally bad acts.
2. Therefore my wrongful act is justified.
Pattern

4.1.5 Scare Tactics
Example:
Diplomat to diplomat: I’m sure you’ll agree that we are the rightful
rulers of the Iraq. It would be regrettable if we had to send armed
forces to demonstrate the validity of our claim.
Scare Tactics
When an arguer threatens harm to a reader or listener
and this threat is irrelevant to the truth of
the arguer’s conclusion.
Fear is a powerful motivator – so powerful that it often
causes us to think and behave irrationally.
Remember

4.1.6 Appeal to Pity
Example:
Student to Lecturer: I know I missed half your classes and failed all my quizzes
and assignments. First my cat died. Then my girlfriend told me she has found
someone else. With all I went through this semester, I don’t think I really deserve
an F. Any chance you might cut me some slack and change my grade to a C or a
D?
Appeal to Pity
When an arguer attempts to evoke feelings of pity or
compassion, where such feelings, however understandable,
are not relevant to the truth of the arguer’s conclusion.
1. P is presented, with the intent to create pity.
2. Therefore claim C is true.
Pattern

4.1.7 Bandwagon Argument
Example:
All the really cool UNITAR students smoke cigarettes.
Therefore, you should, too.
Bandwagon Argument (Peer Pressure)
When an arguer appeals to a person’s desire to be popular,
accepted, or valued, rather than to logically relevant
reasons or evidence.
1. Most (or a select group of) people believe or do X.
2. Therefore, you should believe or do X.
Pattern

4.1.8 Straw Man
Example:
Singh and Karen are arguing about cleaning out their closets:
 Suzie: "We should clean out the closets. They are getting a bit messy.“
 Singh: "Why, we just went through those closets last year. Do we have
to clean them out everyday?"
 Suzie: "I never said anything about cleaning them out every day. You
just want too keep all your junk forever, which is just ridiculous."
Straw Man
When an arguer misrepresents another person’s
position to make it easier to attack.
1. Person A has position X.
2. Person B presents position Y (which is a distorted version of X).
3. Person B attacks position Y.
4. Therefore X is false/incorrect/flawed.
Pattern

4.1.9 Red Herring
Example:
"I think there is great merit in making the requirements stricter for the
graduate students. I recommend that you support it, too. After all, we are
in a budget crisis and we do not want our salaries affected."
Red Herring
When an arguer tries to sidetrack his audience by raising
an irrelevant issue, and then claims that the original
issue has been effectively settled by the
irrelevant diversion.
1. Topic A is under discussion.
2. Topic B is introduced under the guise of being relevant
to topic A (when topic B is actually not relevant to topic A).
3. Topic A is abandoned.
Pattern

4.1.10 Equivocation
Example:
In the summer of 1940, Londoners were bombed almost very
night. To be bombed is to be intoxicated. Therefore, in the
summer of 1940, Londoners were intoxicated almost every
night.
Equivocation
When an arguer uses a key word in an argument in two
(or more) different senses.
Fallacies of Equivocation can be difficult to spot because
they often appear valid, but they aren’t.
Remember

4.1.11 Begging the Question
Example:
I am entitled to say whatever I choose because I have a right
to say whatever I please.
Begging the Question
When an arguer states or assumes as a premise (reason)
the very thing he is seeking to probe as a conclusion.
Arguing in a circle – A because B, B because A.
Reason

I'm trying hard to understand this guy who identifies himself as a
security supervisor and criticizes the police officers in this area. I
can only come up with two solutions. One, he is either a member of
the criminal element, or two, he is a frustrated security guard who
can never make it as a police officer and figures he can take cheap
shots at cops through the newspaper (adapted from a newspaper
call-in column).
Which fallacy?
A) Loaded Question
B) Personal Attack
C) Bandwagon Argument
D) Scare Tactics
4.1 Mini Quiz – Question 1

The Red Cross is worried about the treatment of the
suspected terrorists held by the U.S. at Guantanamo
Bay, Cuba. What do they want the U.S. to do with
them, put them on the beaches of Florida for a
vacation or take them skiing in the Rockies? Come
on, let's worry about the Americans. (adapted from a
newspaper call-in column)
Which fallacy?
A) Bandwagon Argument
B) Personal Attack
C) Straw Man
D) Scare Tactics

“The foolish and the dead alone
never change their opinion.”
- James Russell Lowell

4.2 Fallacies of Insufficient Evidence
Arguments in which the
premises, though logically
relevant to the conclusion, fail
to provide sufficient evidence to
support the conclusion.

4.2 Fallacies of Insufficient Evidence
Inappropriate Appeal
to Authority
Questionable Cause
Appeal to Ignorance Slippery Slope
False Alternatives Weak Analogy
Loaded Question Inconsistency
Hasty Generalizations

4.2.1 Inappropriate Appeal to Authority
Example:
My dentist told me that aliens built the lost city of Atlantis. So,
it’s reasonable to believe that aliens did build the lost city of
Atlantis.
Inappropriate Appeal to Authority
Citing a witness or authority that is untrustworthy.
Authority Assessment
1. Is the source an authority on the subject at issue?
2. Is the source biased?
3. Is the accuracy of the source observations questionable?
4. Is the source known to be generally unreliable?
5. Has the source been cited correctly?
6. Does the source’s claim conflict with expert opinion?
7. Can the source’s claim be settled by an appeal to expert opinion?
8. Is the claim highly improbable on its face?
Tips

4.2.2 Appeal to Ignorance
Example:
Yoda must exist. No one has proved that he
doesn’t exist.
Appeal to Ignorance
Claiming that something is true because no one has
proven it false or vice versa.
“Not proven, therefore false”
If such reasoning were allowed, we could prove almost
any conclusion.
Remember
Agree
I do!

4.2.3 False Alternatives
Example:
The choice in this MPM election is clear: Either we elect
Zubaidah as our next president, or we watch our MPM unity
slide into anarchy and frustration. Clearly, we don’t want that
to happen. Therefore, we should elect Zubaidah as our next
president.
False Alternatives
Posing a false either/or choice.
Fallacy of false alternatives can involve more than
two (2) alternatives. It can also be expressed as a
conditional (if-then) statement.
Remember

4.2.4 Loaded Question
Example:
Lee: Are you still friends with that loser Richard?
Ali: Yes.
Lee: Well, at least you admit he’s a total loser.
Loaded Question
Posing a question that contains an unfair or unwarranted
presupposition.
To respond to a loaded question effectively, one must
distinguish the different questions being asked and respond
to each individually.
Tip

4.2.5 Questionable Cause
Example:
Sarah gets a chain letter that threatens her with dire consequences if she
breaks the chain. She laughs at it and throws it in the garbage. On her
way to work she slips and breaks his arm. When she gets back from the
hospital she sends out 200 copies of the chain letter, hoping to avoid
further accidents.
Questionable Cause
Claiming, without sufficient evidence, that one thing
is the cause of something else.
1. A and B are associated on a regular basis.
2. Therefore A is the cause of B.
Pattern

4.2.6 Hasty Generalization
Example:
Norwegians are lazy. I have two friends who are from there,
and both of them never prepare for class, or do their
homework.
Hasty Generalization
Drawing a general conclusion from a sample that
is biased or too small.
1. A biased sample is one that is not representative of the target population.
2. The target population is the group of people or things that the
generalization is about.
3. Hasty generalizations can often lead to false stereotypes.
Pattern

4.2.7 Slippery Slope
Examples:
“The Malaysian militarily shouldn't get involved in other countries. Once
the government sends in a few troops, it will then send in thousands to
die."
Slippery Slope
Claiming, without sufficient evidence, that a seemingly
harmless action, if taken, will lead to a disastrous
outcome.
1. The arguer claims that if a certain seemingly harmless action, A,
is permitted, A will lead to B, B will lead to C, and so on to D.
2. The arguer holds that D is a terrible thing and therefore should
not be permitted.
3. In fact, there is no good reason to believe that A will actually
lead to D.
Pattern

4.2.8 Weak Analogy
Example:
Nobody would buy a car without first taking it for a test drive.
Why then shouldn’t two mature UNITAR students live
together before they decide whether to get married?
Weak Analogy
Comparing things that aren’t really comparable.
1. List all important similarities between the two cases.
2. List all important dissimilarities between the two cases.
3. Decide whether the similarities or dissimilarities are
more important.
Tip

4.2.9 Inconsistency
Example:
Note found in a Forest Service Suggestion box: Park visitors
need to know how important it is to keep this wilderness
area completely pristine and undisturbed. So why not put up
a few signs to remind people of this fact?
Inconsistency
Asserting inconsistent or contradictory claims.
It is also a mistake to cling stubbornly to an old idea when new
information suggests that the idea is false.
Open-minded to new ideas = Learning
Remember

What's to say against [cigars]? They killed George
Burns at 100. If he hadn't smoked them, he'd have
died at 75. (Bert Sugar, quoted in New York Times,
September 20, 2002)
Which fallacy?
A) Questionable Cause
B) Hasty Generalization
C) Slippery Slope
D) Weak Analogy

According to North Korea's official state-run news agency, "a
war between North Korea and the United States will end with
the delightful victory of North Korea, a newly emerging military
power, in 100 hours. . . . The U. S. [will] be enveloped in flames.
. . and the arrogant empire of the devil will breathe its last".
Given that this prediction comes from the official North Korean
news agency, it is probably true.
(Passage quoted in Nicholas D. Kristof, "Empire of the Devil," New
York Times, April 4, 2003)
Which fallacy?
A) Inappropriate Appeal to Authority
B) Appeal to Ignorance
C) False Alternatives
D) Loaded Question

Jurors in tobacco lawsuits should award judgments so large
that they put tobacco companies out of business. Respecting
the right of tobacco companies to stay in business is akin to
saying there are "two sides" to slavery...
(Anti-tobacco lawyer, quoted in George F. Will, "Court Ruling
Expresses Anti-Smoking Hypocrisy," Wilkes-Barre Times
Leader, May 25, 2003)
Which fallacy?
A) Loaded Question
B) Hasty Generalization
C) Slippery Slope
D) Weak Analogy

Group Activity
Break into groups of 4 - 6, and construct five (5) fallacious
arguments.
Each group can choose any of the 20 fallacies discussed, but
must construct at least two fallacious arguments of each
category: Fallacies of Relevance & Fallacies of Insufficient
Evidence).
The constructed fallacious arguments must discuss the
topics specified in the template provided (Business,
Education, Information Technology, Environment, and
Tourism).
20 min Construct 5 fallacious arguments.
5 min Document constructed arguments into the template provided.
15 min Group presentation & discussion.
The Group leader must submit their findings in hard-copy or soft-copy format to the
lecturer before or during the next class.

Summary – 20 Common Fallacies
Fallacy
An argument that contains a mistake in reasoning.
Fallacies of Relevance
Arguments in which the premises are
logically irrelevant to the conclusion.
Fallacies of Insufficient Evidence
Arguments in which the premises, though
logically relevant to the conclusion, fail to
provide sufficient evidence for the conclusion.
 Personal Attack
 Attacking the Motive
 Look Who’s Talking
 Two Wrongs Make a Right
 Scare Tactics
 Appeal to Pity
 Bandwagon Argument
 Straw Man
 Red Herring
 Equivocation
 Begging the Question
 Inappropriate Appeal to Authority
 Appeal to Ignorance
 False Alternatives
 Loaded Question
 Questionable Cause
 Hasty Generalization
 Slippery Slope
 Weak Analogy
 Inconsistency

References
Book
Chapter 5 (Logical Fallacies -1) & 6 (Logical Fallacies -
2): G Bassham, W Irwin, H Nardone, J M Wallace, Critical
Thinking: A Student's Introduction, McGraw-Hill International
Edition, 2007
Online Resources
Fallacies (The Nizkor Project):
http://www.nizkor.org/features/fallacies/
Cool Optical Illusions:
http://www.coolopticalillusions.com/

Contact Details
Zaid Ali Alsagoff
UNIVERSITI TUN ABDUL RAZAK
16-5, Jalan SS 6/12
47301 Kelana Jaya
Selangor Darul Ehsan
Malaysia
E-mail: zaid.alsagoff@gmail.com
Tel: 603-7627 7238
Fax: 603-7627 7246

Fallacies.ppt

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