This document provides information about logical fallacies and common types of flawed reasoning in arguments. It discusses two main categories of fallacies: fallacies of relevance, where the premises are irrelevant to the conclusion, and fallacies of insufficient evidence, where the premises fail to sufficiently support the conclusion. Specific fallacies explained include personal attacks, straw man, appeal to emotion, false authority, hasty generalization, slippery slope, and inconsistency. The document emphasizes identifying faulty patterns of reasoning and assessing whether evidence and comparisons are appropriate to draw the stated conclusion.

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

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

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

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

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

6. Fallaci
es

7. Fallaci
es
1. Fallacies
of Relevance
2. Fallacies of
Insufficient
Evidence
What
mistake!!!

8. 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.

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

10. 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
statementis true.
– A statement is negatively relevant to another statement if it
provides at least some reason for thinking that the second
statementis false.

11. Fallacies of Relevance
Appeal to Emotion
(Ad Populum)
Begging the Question Red Herring

12. Personal Attack (Ad Hominem)
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 Martin has argued for more emphasis
on music in our F2F classes to facilitate
creativity.
But Martin is a selfish bigheaded fool. I
absolutely refuse to listen to him.
1. X is a bad person.
Pattern

13. 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 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.
1. Xhas biased or has questionable motives.
Pattern

14. 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.
Smokestac
k!
1. X fails to follow his or her ownadvice.
Pattern

15. 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 Zaid’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 badacts.
Pattern

16. 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.
Fear is a powerful motivator – so powerful that it often
causes us to think and behave irrationally.
Remember

17. Appeal to Emotion (Ad Populum)
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?
1. P is presented, with the intent to create pity.
Pattern

18. 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 Taylors
students smoke cigarettes. Therefore, you
should, too.
1. Most (or a select group of) people believe or doX.
Pattern

19. Straw Man
Straw Man
When an arguer misrepresents another person’s
position to make it easier to attack.
Example:
Singh and Karen are arguing about cleaning out their closets:
 Suzie: "We should clean out the closets. Theyare 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."
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

20. 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
graduate students. I recommend that you support it, too. After all, we
are in a budget crisis and we do not want oursalaries affected."
1. Topic A is under discussion.
2. Topic B is introduced under the guise of being relevant
3. Topic A is abandoned.
Pattern

21. 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.
Fallacies of Equivocationcan be difficult to spot because
they often appear valid, but they aren’t.
Remember

22. 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.
Arguing in a circle – A because B, B becauseA.
Reason

23. Mini Quiz – Question 1
I'm trying hard to understand this guy who identifies himself as a
security supervisor and criticizes the police officersin 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
newspapercall-in column).
Which fallacy?
A) Loaded Question
B) Personal Attack
C) Bandwagon Argument
D) Scare Tactics

24. 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?
A) Bandwagon Argument
B) Personal Attack
C) Straw Man
D) Scare Tactics

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

26. 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.

27. 4.2 Fallacies of Insufficient
Evidence

28. 4.2.1 False
Authority
False 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
aliensdid build the lost city ofAtlantis.
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

29. 4.2.2 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.
If such reasoning were allowed, we could provealmost
any conclusion.
Remember
Agree
I do!
“Not proven, therefore false”

30. 4.2.3 False
Dilemma
False Dilemma
Posing a false either/or choice.
Example:
The choice in this MPP election is clear: Either we
elect Zaki as our next president, or we watch
our MPP unity slide into anarchy and
frustration. Clearly, we don’t want that to
happen. Therefore, we should elect Zaki as our
next president.
Fallacy of false dilemma can involve more than
conditional (if-then) statement.
Remember

31. 4.2.4 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.
To respond to a loaded question effectively, one must
distinguish the different questions being asked andrespond
to each individually.
Tip

32. 4.2.5 False
Cause
False Cause
Claiming, without sufficient evidence, that one thing
is the cause of something else.
Example:
Effa 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 her arm. When she gets back from
the hospital she sends out 200 copies of the chain letter, hoping to
avoid further accidents.
1. A and B are associated on a regularbasis.
Pattern

33. 4.2.6 Hasty
Generalization
Hasty Generalization
Drawing a general conclusion from a sample that
is biased or too small.
Example:
Malays are lazy. I have two friends who are
Malays, and both of them never prepare for
class, or do their homework.
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

34. Cont’
d
• …occurs when one draws a general conclusion from a
sample that is biased or too small.
– Biased sample: I polled 100 professors from 100
schools, only 25% of them believed in peace. I guess
most Malaysians don’t believe in peace anymore.
– Too small of a sample: I asked my professors if they
believed in peace, and only one did. I guess professors
don’t believe in peace anymore.
• If it doesn’t have a “general conclusion,” then it’s not a
generalization .
– That biker with the swastika tattoo and brass knuckles will
probably beat me up if I talk to him.
– Since this argument draws a conclusion about one
biker, and not all (or most) of them, it is not a
“generalization” at all.

35. 4.2.7 Slippery
Slope
Slippery Slope
Claiming, without sufficient evidence, that a seemingly
harmless action, if taken, will lead to a disastrous
outcome.
Examples:
• “The Malaysian militarily shouldn't get involved in other countries.
Oncethe government sends in a few troops, it will then send in
thousands to die."
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.
Pattern

36. 4.2.8 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 UiTM students live together before
they decide whether or not to get married?
1. List all important similaritiesbetween the two cases.
2. List all important dissimilarities between the two cases.
3. Decide whether the similarities or dissimilarities are
more important.
Tip

37. Cont’
d
• …occurs when an arguer compares two (or more) things that
aren’t really comparable in the relevant respect.
– e.g., Lettuce is leafy and green and good on burgers.
Poison Ivy leafy and green. It would
be good on burgers too.
• Common forms:
– A has characteristics w, x, y and z. B has characteristics w,
x and
y. Therefore, B probably has characteristic z too.
– A is x and y. B is x and y. C is x. So C is y.
• Many exceptions:
– Alice lives in a mansion and she is rich. Bruce lives in a
mansion.
Bruce is probably rich too.
• The form is easy to spot, but—quite often—to know whether
it is fallacy or not, you just have to know whether the shared
characteristics are relevant to the concluded one.

38. 4.2.9
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 onthe trees to remind people of
thisfact?
It is also a mistake to cling stubbornly to an old idea whennew
information suggests that the idea is false.
Remember

39. 4.2 Mini Quiz –
Question 1
What to say against [cigars]? They killed
George Burns at 100. If he had not
smoked them, he'd
have died at 75. (Bert Sugar, quoted in
New York Times, September 20,
2002)
Which fallacy?
A) False Cause
B) Hasty Generalization
C) Slippery Slope

40. 4.2 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?
A) False Authority
B) Appeal to Ignorance
C) False Alternatives

41. 4.2 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
Anti-Smoking Hypocrisy," Wilkes-Barre Times Leader, May 25,
2003)
Which fallacy?
A) Loaded Question
B) Hasty Generalization
C) Slippery Slope

42. 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 InsufficientEvidence).
• 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 nextclass.

43. Summary – 20 Common
Fallacies Fallacy
An argument that contains a mistake in reasoning.
Fallacies ofRelevance
Arguments in which the premises are
logically irrelevant to theconclusion.
Fallacies of InsufficientEvidence
Arguments in which the premises, though
logically relevant to the conclusion, fail to
provide sufficient evidence for the conclusion.
 Personal Attack (Ad Hominem)
 Attacking the Motive
 Look Who’s Talking
 Two Wrongs Make a Right
 Scare Tactics
 Appeal toEmotion
 Bandwagon Argument
 Straw Man
 Red Herring
 Equivocation
 Begging the Question
 False Authority
 Appeal toIgnorance
 False Dilemma
 Loaded Question
 False Cause
 Hasty Generalization
 Slippery Slope
 Weak Analogy
 Inconsistency

44. Referenc
es
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/fallaci
es/