Critical & Creative Thinking
@ Herman
J. Suhendra
Produced by Herman J. Suhendra
A.B. Gadjah Mada University & M.A. University of Santo Tomas, Manila
Critical & Creative Thinking
@ Herman J. Suhendra
Produced by Herman J. Suhendra
A.B. Gadjah Mada University & M.A. University of Santo Tomas, Manila
Fallacies
Man or Woman?
How many legs does this elephant have?
Which officer is the tallest?
Is this wave moving?
Module: Fallacies
1. Fallacies
of Relevance
What
mistake!!!
2. Fallacies of
Insufficient
Evidence
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
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.
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
Personal Attack
Personal Attack
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.
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.
Attacking the Motive
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.
Example:
Donald Duck has argued that we need to build a new campus. But Duck is
the owner of Dunkin’s Construction Company. He’ll make a fortune if his
company is picked to build the new campus. Obviously, Duck’s
argument is a lot of self-serving nonsense.
Pattern
1. X has biased or has questionable motives.
2. Therefore, X’s arguments or claim should be rejected.
Look Who’s Talking
Look Who’s Talking (tu quoque)
When an arguer rejects another person’s argument
or claim because that person is a hypocrite.
Example:
Doctor: You should quite smoking.
Patient: Look who’s talking! I’ll quit when you do, Dr. Smokestack!
Pattern
1. X fails to follow his or her own advice.
2. Therefore, X’s claim or argument should be rejected.
Two Wrongs Make a Right
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.
Examples:
1. “I don’t feel guilty about cheating on Herman’s online quiz. Half
the class cheats on his quiz.”
2. “Why pick on me, officer? Everyone else is using drugs.”
Pattern
1. Others are committing worse or equally bad acts.
2. Therefore my wrongful act is justified.
Scare Tactics
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.
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.
Remember
Fear is a powerful motivator – so powerful that it often
causes us to think and behave irrationally.
Appeal to Pity
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.
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?
Pattern
1. P is presented, with the intent to create pity.
2. Therefore claim C is true.
Bandwagon Argument
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.
Example:
All the really cool UMN students smoke cigarettes.
Therefore, you should, too.
Pattern
1. Most (or a select group of) people believe or do X.
2. Therefore, you should believe or do X.
Straw Man
Straw Man
When an arguer misrepresents another person’s
position to make it easier to attack.
Example:
Singa and Karen are arguing about cleaning out their closets:
 Suzie: "We should clean out the closets. They are getting a bit messy.“
 Singa: "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."
1. Person A has position X.
Pattern
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.
Red Herring
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.
Example:
"I think there is great merit in making the requirements stricter for the
college students. I recommend that you support it, too. After all, we are
in a budget crisis and we do not want our salaries affected."
Pattern
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.
Equivocation
Equivocation
When an arguer uses a key word in an argument in two
(or more) different senses.
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.
Remember
Fallacies of Equivocation can be difficult to spot because
they often appear valid, but they aren’t.
Begging the Question
Begging the Question
When an arguer states or assumes as a premise (reason)
the very thing he is seeking to probe as a conclusion.
Example:
I am entitled to say whatever I choose because I have a
right to say whatever I please.
Reason
Arguing in a circle – A because B, B because A.
Mini Quiz – Question 1
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
Which fallacy?
Loaded Question
Personal Attack
Bandwagon Argument
Scare Tactics
Mini Quiz – Question 2
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?
Straw man
Personal Attack
Bandwagon Argument
Scare Tactics
“The foolish and the dead alone
never change their opinion.”
- James Russell Lowell
Fallacies of Insufficient Evidence
Inappropriate Appeal to
Authority
Questionable Cause
Appeal to Ignorance
Slippery Slope
False Alternatives
Weak Analogy
Loaded Question
Inconsistency
Hasty Generalizations
Inappropriate Appeal to Authority
Inappropriate Appeal to Authority
Citing a witness or authority that is untrustworthy.
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.
Authority Assessment
Tips
1.
2.
3.
4.
5.
6.
7.
8.
Is the source an authority on the subject at issue?
Is the source biased?
Is the accuracy of the source observations questionable?
Is the source known to be generally unreliable?
Has the source been cited correctly?
Does the source’s claim conflict with expert opinion?
Can the source’s claim be settled by an appeal to expert opinion?
Is the claim highly improbable on its face?
Appeal to Ignorance
Appeal to Ignorance
Claiming that something is true because no one has
proven it false or vice versa.
Example:
Yoda must exist. No one has proved that he doesn’t exist.
Agree
I do!
Remember
“Not proven, therefore false”
If such reasoning were allowed, we could prove almost
any conclusion.
False Alternatives
False Alternatives
Posing a false either/or choice.
Example:
The choice in this SCA election is clear: Either we elect Zu as our next
president, or we watch our SCA unity slide into anarchy and frustration.
Clearly, we don’t want that to happen. Therefore, we should elect Zu as
our next president.
Remember
Fallacy of false alternatives can involve more than
two (2) alternatives. It can also be expressed as a
conditional (if-then) statement.
Loaded Question
Loaded Question
Posing a question that contains an unfair or unwarranted
presupposition.
Example:
Lee: Are you still friends with that loser Richard?
Ali: Yes.
Lee: Well, at least you admit he’s a total loser.
Tip
To respond to a loaded question effectively, one must
distinguish the different questions being asked and respond
to each individually.
Questionable Cause
Questionable Cause
Claiming, without sufficient evidence, that one thing
is the cause of something else.
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.
Pattern
1. A and B are associated on a regular basis.
2. Therefore A is the cause of B.
Hasty Generalization
Hasty Generalization
Drawing a general conclusion from a sample that
is biased or too small.
Example:
Indonesians are lazy. I have two friends who are from there, and both of
them never prepare for class, or do their homework.
Pattern
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.
Slippery Slope
Slippery Slope
Claiming, without sufficient evidence, that a seemingly
harmless action, if taken, will lead to a disastrous
outcome.
Examples:
“Indonesia militarily shouldn't get involved in other countries. Once the
government sends in a few troops, it will then send in thousands to die."
1.
2.
Pattern
3.
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.
The arguer holds that D is a terrible thing and therefore should
not be permitted.
In fact, there is no good reason to believe that A will actually
lead to D.
Weak Analogy
Weak Analogy
Comparing things that aren’t really comparable.
Example:
Nobody would buy a car without first taking it for a test drive.
Why then shouldn’t two mature PresUniv students live
together before they decide whether to get married?
Tip
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.
Inconsistency
Inconsistency
Asserting inconsistent or contradictory claims.
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?
Remember
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
Mini Quiz – Question 1
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?
Questionable Cause
Hasty Generalization
Slippery Slope
Weak Analogy
Mini Quiz – Question 2
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?
Inappropriate Appeal to Authority
Appeal to Ignorance
False Alternatives
Loaded Question
Mini Quiz – Question 3
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 AntiSmoking Hypocrisy," Wilkes-Barre Times Leader, May 25, 2003)
Which fallacy?
Loaded Question
Hasty Generalization
Slippery Slope
Weak Analogy
Exercise
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
(Business, Education, Information Technology, Environment, and
Tourism).
20 min
Construct 5 fallacious arguments.
5 min
Document constructed arguments.
15 min
Group presentation & discussion
The Group leader must submit their findings in hard or soft-copy format to the
lecturer and send to his email before or during the next class.
Summary – 20 Common Fallacies
Fallacy
An argument that contains a mistake in reasoning.

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







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Fallacies of Relevance
Fallacies of Insufficient Evidence
Arguments in which the premises are
logically irrelevant to the conclusion.
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
Any Questions?
The End – Thank You!
Watch-out!
http://mycriticalthinking.pbworks.com