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Critical & Creative ThinkingCritical & Creative Thinking@ @ Herman J. SuhendraHerman J. Suhendra Produced by Herman J. SuhendraProduced by Herman J. Suhendra
A.B. Gadjah Mada University & M.A. University of Santo Tomas, ManilaA.B. Gadjah Mada University & M.A. University of Santo Tomas, Manila
Critical & Creative ThinkingCritical & Creative Thinking@ @ Herman J. SuhendraHerman J. Suhendra Produced by Herman J. SuhendraProduced by Herman J. Suhendra
A.B. Gadjah Mada University & M.A. University of Santo Tomas, ManilaA.B. Gadjah Mada University & M.A. University of Santo Tomas, Manila
Fallacies
Man or Woman?Man or Woman?
How many legs does this elephant have?How many legs does this elephant have?
Which officer is the tallest?Which officer is the tallest?
Is this wave moving?Is this wave moving?
Module: FallaciesModule: Fallacies
2. Fallacies of Insufficient Evidence
1. Fallacies of Relevance What
mistake!!!
What is a Fallacy?What is a Fallacy?
A (logical) fallacy is an argument that contains a mistake contains a mistake in reasoningin reasoning.
Fallacies can be divided into two general types:
Fallacies of RelevanceFallacies of Relevance Arguments in which the premises are logically irrelevant to the conclusion.
Fallacies of Insufficient EvidenceFallacies 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 RelevanceFallacies of RelevanceA statement is RELEVANTRELEVANT 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 RelevanceFallacies of Relevance
Personal AttackPersonal Attack Appeal to PityAppeal to Pity
Attacking the MotiveAttacking the Motive Bandwagon Bandwagon ArgumentArgument
Look Who’s TalkingLook Who’s Talking Straw ManStraw Man
Begging the Begging the QuestionQuestion
Red HerringRed Herring
Scare TacticsScare Tactics EquivocationEquivocation
Two Wrongs Make a RightTwo Wrongs Make a Right
Personal AttackPersonal Attack
Personal AttackPersonal Attack
Personal AttackPersonal AttackWhen 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.
Personal AttackPersonal AttackWhen 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 MotiveAttacking 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.
Attacking the MotiveAttacking 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.
1.1. XX has biased or has questionable motives. has biased or has questionable motives.2.2. Therefore, Therefore, X’sX’s arguments or claim should be rejected arguments or claim should be rejected.1.1. XX has biased or has questionable motives. has biased or has questionable motives.2.2. Therefore, Therefore, X’sX’s arguments or claim should be rejected arguments or claim should be rejected.Patter
n
Look Who’s TalkingLook Who’s Talking
Look Who’s Talking (tu quoque) Look Who’s Talking (tu quoque) When an arguer rejects another person’s argument
or claim because that person is a hypocrite.
Look Who’s Talking (tu quoque) 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!
1.1. X X fails to follow his or her own advice.fails to follow his or her own advice.2.2. Therefore, Therefore, X’X’s claim or argument should be rejected.s claim or argument should be rejected.1.1. X X fails to follow his or her own advice.fails to follow his or her own advice.2.2. Therefore, Therefore, X’X’s claim or argument should be rejected.s claim or argument should be rejected.Patter
n
Two Wrongs Make a RightTwo Wrongs Make a Right
Two Wrongs Make a RightTwo Wrongs Make a RightWhen an arguer attempts to justify a wrongful act
by claiming that some other act is just as bad or worse.
Two Wrongs Make a RightTwo Wrongs Make a RightWhen 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.”
1. Others are committing worse or equally bad acts. 1. Others are committing worse or equally bad acts. 2. Therefore my wrongful act is justified.2. Therefore my wrongful act is justified. 1. Others are committing worse or equally bad acts. 1. Others are committing worse or equally bad acts. 2. Therefore my wrongful act is justified.2. Therefore my wrongful act is justified. Patter
n
Scare TacticsScare Tactics
Scare TacticsScare TacticsWhen an arguer threatens harm to a reader or listener
and this threat is irrelevant to the truth of
the arguer’s conclusion.
Scare TacticsScare TacticsWhen 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.
Fear is a powerful motivatorFear is a powerful motivator – so powerful that it often causes us to think and behave irrationally.Fear is a powerful motivatorFear is a powerful motivator – so powerful that it often causes us to think and behave irrationally.Rememb
er
Appeal to PityAppeal to Pity
Appeal to PityAppeal to PityWhen 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.
Appeal to PityAppeal to PityWhen 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?
1.1. P is presented, with the intent to create pity. P is presented, with the intent to create pity. 2. Therefore claim C is true.2. Therefore claim C is true. 1.1. P is presented, with the intent to create pity. P is presented, with the intent to create pity. 2. Therefore claim C is true.2. Therefore claim C is true. Patter
n
Bandwagon ArgumentBandwagon Argument
Bandwagon Argument (Peer Pressure)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.
Bandwagon Argument (Peer Pressure)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.
1. Most (or a select group of) people believe or do X.1. Most (or a select group of) people believe or do X.2. Therefore, you should believe or do X.2. Therefore, you should believe or do X.1. Most (or a select group of) people believe or do X.1. Most (or a select group of) people believe or do X.2. Therefore, you should believe or do X.2. Therefore, you should believe or do X.Patter
n
Straw ManStraw ManStraw ManStraw Man
When an arguer misrepresents another person’s position to make it easier to attack.
Straw ManStraw ManWhen 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. 1. Person A has position X. Person A has position X. 2. Person B presents position Y (which is a distorted version of X). 2. Person B presents position Y (which is a distorted version of X). 3. Person B attacks position Y. 3. Person B attacks position Y. 4. Therefore X is false/incorrect/flawed.4. Therefore X is false/incorrect/flawed.
1. 1. Person A has position X. Person A has position X. 2. Person B presents position Y (which is a distorted version of X). 2. Person B presents position Y (which is a distorted version of X). 3. Person B attacks position Y. 3. Person B attacks position Y. 4. Therefore X is false/incorrect/flawed.4. Therefore X is false/incorrect/flawed.
Pattern
Red HerringRed Herring
Red HerringRed HerringWhen 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.
Red HerringRed HerringWhen 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."
1. Topic 1. Topic AA is under discussion. is under discussion. 2. Topic 2. Topic BB is introduced under the guise of being relevant is introduced under the guise of being relevant to topic A (when topic B is actually not relevant to topic A). to topic A (when topic B is actually not relevant to topic A). 3. Topic 3. Topic A A is abandoned.is abandoned.
1. Topic 1. Topic AA is under discussion. is under discussion. 2. Topic 2. Topic BB is introduced under the guise of being relevant is introduced under the guise of being relevant to topic A (when topic B is actually not relevant to topic A). to topic A (when topic B is actually not relevant to topic A). 3. Topic 3. Topic A A is abandoned.is abandoned.
Pattern
EquivocationEquivocationEquivocationEquivocation
When an arguer uses a key word in an argument in two
(or more) different senses.
EquivocationEquivocationWhen 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.
Fallacies of Equivocation Fallacies of Equivocation can be difficult to spot becausethey often appear valid, but they aren’t.Fallacies of Equivocation Fallacies of Equivocation can be difficult to spot becausethey often appear valid, but they aren’t.Rememb
er
Begging the QuestionBegging the Question
Begging the QuestionBegging the QuestionWhen an arguer states or assumes as a premise (reason)
the very thing he is seeking to probe as a conclusion.
Begging the QuestionBegging the QuestionWhen 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.
Arguing in a circleArguing in a circle – A because B, B because A.Arguing in a circleArguing in a circle – A because B, B because A.Reason
Mini Quiz – Question 1Mini Quiz – Question 1
Which fallacy?Which fallacy? Loaded QuestionLoaded QuestionPersonal AttackPersonal AttackBandwagon ArgumentBandwagon ArgumentScare TacticsScare Tactics
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
Mini Quiz – Question 2Mini 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?Which fallacy? Straw manStraw manPersonal AttackPersonal AttackBandwagon ArgumentBandwagon ArgumentScare TacticsScare Tactics
“The foolish and the dead alone never change their opinion.”
- James Russell Lowell
Fallacies of Insufficient EvidenceFallacies of Insufficient Evidence
Inappropriate Appeal to Inappropriate Appeal to AuthorityAuthority
Questionable CauseQuestionable Cause
Appeal to IgnoranceAppeal to Ignorance Slippery SlopeSlippery Slope
False Alternatives False Alternatives Weak AnalogyWeak Analogy
Loaded QuestionLoaded Question InconsistencyInconsistency
Hasty Generalizations Hasty Generalizations
Inappropriate Appeal to AuthorityInappropriate Appeal to Authority
Inappropriate Appeal to AuthorityInappropriate Appeal to AuthorityCiting a witness or authority that is untrustworthy.
Inappropriate Appeal to AuthorityInappropriate Appeal to AuthorityCiting 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 AssessmentAuthority Assessment1. 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?
Authority AssessmentAuthority Assessment1. 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
Appeal to IgnoranceAppeal to Ignorance
Appeal to IgnoranceAppeal to IgnoranceClaiming that something is true because no one has
proven it false or vice versa.
Appeal to IgnoranceAppeal to IgnoranceClaiming 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.
““Not proven, therefore false”Not proven, therefore false”If such reasoning were allowed, we could prove almostany conclusion.
““Not proven, therefore false”Not proven, therefore false”If such reasoning were allowed, we could prove almostany conclusion.
Remember
AgreAgree I e I do!do!
False AlternativesFalse Alternatives
False AlternativesFalse AlternativesPosing a false either/or choice.
False AlternativesFalse AlternativesPosing 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.
Fallacy of false alternatives Fallacy of false alternatives can involve more thanmore thantwo (2) alternativestwo (2) alternatives. It can also be expressed as a conditional (i (if-thenf-then) ) statement.
Fallacy of false alternatives Fallacy of false alternatives can involve more thanmore thantwo (2) alternativestwo (2) alternatives. It can also be expressed as a conditional (i (if-thenf-then) ) statement.Rememb
er
Loaded QuestionLoaded Question
Loaded QuestionLoaded QuestionPosing a question that contains an unfair or unwarranted
presupposition.
Loaded QuestionLoaded QuestionPosing 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.
To respond to a loaded question effectivelyTo respond to a loaded question effectively, , one mustdistinguish the different questions being asked and respondto each individually.
To respond to a loaded question effectivelyTo respond to a loaded question effectively, , one mustdistinguish the different questions being asked and respondto each individually.
Tip
Questionable CauseQuestionable Cause
Questionable CauseQuestionable CauseClaiming, without sufficient evidence, that one thing
is the cause of something else.
Questionable CauseQuestionable CauseClaiming, 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.
1. 1. A and B are associated on a regular basis. A and B are associated on a regular basis. 2. Therefore A is the cause of B.2. Therefore A is the cause of B. 1. 1. A and B are associated on a regular basis. A and B are associated on a regular basis. 2. Therefore A is the cause of B.2. Therefore A is the cause of B.
Pattern
Hasty GeneralizationHasty Generalization
Hasty GeneralizationHasty GeneralizationDrawing a general conclusion from a sample that
is biased or too small.
Hasty GeneralizationHasty GeneralizationDrawing 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.
1. A biasedbiased sample is one that is not representative of the target population. 2. The target populationtarget population is the group of people or things that the generalization is about. 3. Hasty generalizations can often lead to false stereotypesstereotypes.
1. A biasedbiased sample is one that is not representative of the target population. 2. The target populationtarget population is the group of people or things that the generalization is about. 3. Hasty generalizations can often lead to false stereotypesstereotypes.
Pattern
Slippery SlopeSlippery Slope
Slippery SlopeSlippery SlopeClaiming, without sufficient evidence, that a seemingly
harmless action, if taken, will lead to a disastrous
outcome.
Slippery SlopeSlippery SlopeClaiming, 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."
1.1. The arguer claims that if a certain seemingly harmless action, A, 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.is permitted, A will lead to B, B will lead to C, and so on to D.
2.2. The arguer holds that D is a terrible thing and therefore should The arguer holds that D is a terrible thing and therefore should not be permitted.not be permitted.
3.3. In fact, there is no good reason to believe that A will actually In fact, there is no good reason to believe that A will actually lead to D.lead to D.
1.1. The arguer claims that if a certain seemingly harmless action, A, 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.is permitted, A will lead to B, B will lead to C, and so on to D.
2.2. The arguer holds that D is a terrible thing and therefore should The arguer holds that D is a terrible thing and therefore should not be permitted.not be permitted.
3.3. In fact, there is no good reason to believe that A will actually In fact, there is no good reason to believe that A will actually lead to D.lead to D.
Pattern
Weak AnalogyWeak Analogy
Weak AnalogyWeak AnalogyComparing things that aren’t really comparable.
Weak AnalogyWeak AnalogyComparing 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?
1. List all important similaritiesimportant similarities between the two cases.2. List all important dissimilaritiesimportant dissimilarities between the two cases.3. Decide Decide whether the similarities or dissimilarities are more important.
1. List all important similaritiesimportant similarities between the two cases.2. List all important dissimilaritiesimportant dissimilarities between the two cases.3. Decide Decide whether the similarities or dissimilarities are more important.
Tip
InconsistencyInconsistency
Inconsistency Inconsistency Asserting inconsistent or contradictory claims.
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?
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 = LearningOpen-minded to new ideas = Learning
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 = LearningOpen-minded to new ideas = LearningRemember
Mini Quiz – Question 1Mini 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?Which fallacy? Questionable CauseQuestionable CauseHasty GeneralizationHasty GeneralizationSlippery SlopeSlippery SlopeWeak AnalogyWeak Analogy
Mini Quiz – Question 2Mini 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?Which fallacy? Inappropriate Appeal to AuthorityInappropriate Appeal to Authority Appeal to IgnoranceAppeal to Ignorance False AlternativesFalse Alternatives Loaded QuestionLoaded Question
Mini Quiz – Question 3Mini 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 Anti-
Smoking Hypocrisy," Wilkes-Barre Times Leader, May 25, 2003)
Which fallacy?Which fallacy? Loaded QuestionLoaded Question
Hasty GeneralizationHasty Generalization Slippery SlopeSlippery Slope Weak AnalogyWeak Analogy
Exercise Exercise
Group ActivityGroup Activity
20 min Construct 5 fallacious arguments.
5 min Document constructed arguments.
15 min Group presentation & discussionThe 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.
• Break into groups of 4 - 6, and construct five (5) fallacious arguments.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).
Summary – 20 Common FallaciesSummary – 20 Common Fallacies
FallacyFallacy
An argument that contains a mistake in reasoningcontains a mistake in reasoning.
Fallacies of RelevanceFallacies of RelevanceArguments in which the premises are logically irrelevant to the conclusion.
Fallacies of Insufficient EvidenceFallacies of Insufficient EvidenceArguments in which the premises, though logically relevant to the conclusion, fail to
provide sufficient evidence for the conclusion.
Personal AttackPersonal Attack Attacking the Motive Attacking the Motive Look Who’s TalkingLook Who’s Talking Two Wrongs Make a RightTwo Wrongs Make a Right Scare TacticsScare Tactics Appeal to PityAppeal to Pity Bandwagon ArgumentBandwagon Argument Straw ManStraw Man Red HerringRed Herring EquivocationEquivocation Begging the QuestionBegging the Question
Inappropriate Appeal to AuthorityInappropriate Appeal to Authority
Appeal to IgnoranceAppeal to Ignorance
False AlternativesFalse Alternatives
Loaded QuestionLoaded Question
Questionable CauseQuestionable Cause
Hasty GeneralizationHasty Generalization
Slippery SlopeSlippery Slope
Weak AnalogyWeak Analogy
InconsistencyInconsistency
Any Questions?Any Questions?
The End – Thank You!The End – Thank You!
Watch-out!Watch-out!
http://mycriticalthinking.pbworks.comhttp://mycriticalthinking.pbworks.com
