12 Fallacies Identified and Explained

The arguments below contain various kinds of fallacies. Evaluate each and identify the fallacy using the matching list. See the master list of fallacies.

1. We can recognize that athletes that participate in sports must be given special consideration within our grading system, or we can let the university sink into athletic oblivion.

2. I don't know what colleges are teaching these days! I have just received a letter of application from a young man who graduated from the state university last June. It was a wretched letter--badly written, with elementary errors in spelling, punctuation, and grammar. The state university does not deserve the tax support that it is getting.

3. All right-thinking people will support the Board of Education's decision to destroy novels in the school libraries that are offensive to the moral standards of the community. If there were an epidemic of typhoid, the health authorities would be expected to do everything in their power to wipe it out. Pornography is worse than typhoid, since it corrupts the minds and morals of the young, not just their bodies. The school board is to be applauded for their prompt action in wiping out
this moral disease.

4. Despite endless efforts, no one has been able to prove that God exists; we may just as well stop trying and accept the truth: there is no God.

5. Alicia started gaining more weight than ever when she started taking Slimdown; the stuff must be fattening!

6. No sensible person would support the Equal Rights Amendment. If it were to pass, we would have women in combat and unisex bathrooms. Eventually, we would not even be able to tell the women from the men!

7. How can Clinton be leading this country! He's a draft-dodging, pot-smoking, womanizer!!

8. Michael Jordan wore that brand, so those must to be the best basketball shoes.

9. The difference in the outcome was Jefferson's missed field goal. If he had put it through, we'd be going to the Super Bowl.

10. Don't ignore the woman who gave you birth, raised you, loved you then, and loves you still. Remember your mom on Mother's Day.

11. So what if I didn't claim all of the money I earned on my taxes? Lots of people under-report their income.

12. That's gotta be a great line of clothes. Have you seen the prices and the people endorsing it?

MATCHING LIST

Each argument commits only one fallacy, and each fallacy is only used once.

a. False analogy.

b. Appeal to authority.

c. Post hoc ergo propter hoc.

d. Attacking the person.

e. Two wrongs.

f. Non sequitur.

g. Equivocation.

h. False dilemma.

i. Black and white (slippery slope).

j. Hasty generalization.

k. Contrary-to-fact hypothesis.

l. Ad ignorantium.

m. Appeal to emotion.

MASTER LIST OF LOGICAL FALLACIES

The following is a list of all the fallacies that are discussed in this course. Some are covered in the textbook and others will be introduced by the faculty member. It will be helpful to keep this page handy. Space has been provided for you to take notes as each fallacy is discussed during the course.

1. Ad hominem or ATTACKING THE PERSON. Attacking the arguer rather than his/her argument. Example: John's objections to capital punishment carry no weight since he is a convicted felon. Note: Saying something negative about someone is not automatically ad hominem. If a person (politician for example) is the issue, then it is not a fallacy to criticize him/her.

2. Ad ignorantium or APPEAL TO IGNORANCE. Arguing on the basis of what is not known and cannot be proven. (Sometimes called the "burden of proof" fallacy). If you can't prove that something is true then it must be false (and vice versa). Example: You can't prove there isn't a Loch Ness Monster, so there must be one.

3. Ad verecundiam or APPEAL TO AUTHORITY. This fallacy tries to convince the listener by appealing to the reputation of a famous or respected person. Oftentimes it is an authority in one field who is speaking out of his or her field of expertise. Example: Sports stars selling cars or hamburgers. Or, the actor on a TV commercial that says, "I'm not a doctor, but I play one on TV."

4. AFFIRMING THE CONSEQUENT. An invalid form of the conditional argument. In this case, the second premise affirms the consequent of the first premise and the conclusion affirms the antecedent. Example: If he wants to get that job, then he must know Spanish. He knows Spanish, so the job is his.

5. AMPHIBOLY. A fallacy of syntactical ambiguity where the position of words in a sentence or the juxtaposition of two sentences conveys a mistaken idea. This fallacy is like equivocation except that the ambiguity does not result from a shift in meaning of a single word or phrase, but is created by word placement.. Example: Jim said he saw Jenny walk her dog through the window. Ow! She should be reported for animal abuse.

6. APPEAL TO EMOTION. In this fallacy, the arguer uses emotional appeals rather than logical reasons to persuade the listener. The fallacy can appeal to various emotions including pride, pity, fear, hate, vanity, or sympathy. Generally, the issue is oversimplified to the advantage of the arguer. Example: In 1972, there was a widely-printed advertisement printed by the Foulke Fur Co., which was in reaction to the frequent protests against the killing of Alaskan seals for the making of fancy furs. According to the advertisement, clubbing the seals was one of the great conservation stories of our history, a mere exercise in wildlife management, because "biologists believe a healthier colony is a controlled colony."

7. ARGUMENT FROM ANALOGY or FALSE ANALOGY. An unsound form of
inductive argument in which an argument relies heavily on a weak analogy
to prove its point. Example: This must be a great car, for, like the
finest watches in the world, it was made in Switzerland.

8. BEGGING THE QUESTION. An argument in which the conclusion is
implied or already assumed in the premises. Also said to be a circular
argument. Example: Of course the Bible is the word of God. Why? Because
God says so in the Bible.

9. SLIPPERY SLOPE. A line of reasoning that argues against taking a
step because it assumes that if you take the first step, you will
inevitably follow through to the last. This fallacy uses the valid form
of hypothetical syllogism, but uses guesswork for the premises. Example:
We can't allow students any voice in decision making on campus; if we
do, it won't be long before they are in total control.

10. COMMON BELIEF (Sometimes called the "bandwagon" fallacy or
'appeal to popularity"). This fallacy is committed when we assert a
statement to be true on the evidence that many other people allegedly
believe it. Being widely believed is not proof or evidence of the truth.
Example: Of course Nixon was guilty in Watergate. Everybody knows that.

11. PAST BELIEF. A form of the COMMON BELIEF fallacy. The same error
in reasoning is committed except the claim is for belief or support in
the past. Example: We all know women should obey their husbands. After
all, marriage vows contained those words for centuries.

12. CONTRARY TO FACT HYPOTHESIS. This fallacy is committed when we
state with an unreasonable degree of certainty the results of an event
that might have occurred but did not. Example: If President Bush had not
gone into the Persian Gulf with military force when he did, Saddam
Hussein would control the world's oil from Saudi Arabia today.

13. DENYING THE ANTECEDENT. An invalid form of the conditional
argument. In this one, the second premise denies the antecedent of the
first premise, and the conclusion denies the consequent. Often mistaken
for modus tollens. Example: If she qualifies for a promotion, she must
speak English. She doesn't qualify for the promotion, so she must not
know how to speak English.

14. DIVISION. This fallacy is committed when we conclude that any
part of a particular whole must have a characteristic because the whole
has that characteristic. Example: I am sure that Karen plays the piano
well, since her family is so musical.

15. COMPOSITION. This fallacy is committed when we conclude that a
whole must have a characteristic because some part of it has that
characteristic. Example: The Dawson clan must be rolling in money, since
Fred Dawson makes a lot from his practice.

16. FAR-FETCHED HYPOTHESIS. A fallacy of inductive reasoning that
is committed when we accept a particular hypothesis when a more
acceptable hypothesis, or one more strongly based in fact, is available.
Example: The African-American church was set afire after the civil
rights meeting last night; therefore, it must have been done by the
leader and the minister to cast suspicion on the local segregationists.

17. FALSE DILEMMA (often called the either/or fallacy or false
dichotomy). This fallacy assumes that we must choose one of two
alternatives instead of allowing for other possibilities; a false form
of disjunctive syllogism. Example: "America, love it or leave it." (The
implication is, since you don't love it the only option is to leave it).

18.EQUIVOCATION. This fallacy is a product of semantic ambiguity. The
arguer uses the ambiguous nature of a word or phrase to shift the
meaning in such a way as to make the reason offered appear more
convincing. Example: We realize that workers are idle during the period
of lay-offs. But the government should never subsidize idleness, which
has often been condemned as a vice. Therefore, payments to laid off
workers are wrong.

19.HASTY GENERALIZATION. A generalization accepted on the support of a
sample that is too small or biased to warrant it. Example: All men are
rats! Just look at the louse that I married.

20.POST HOC, ERGO PROPTER HOC. ("After this, therefore caused by this.")
A form of the false cause fallacy in which it is inferred that
because one event followed another it is necessarily caused by that
event. Example: Mary joined our class and the next week we all did
poorly on the quiz. It must be her fault.

21.INCONSISTENCY. A discourse is inconsistent or self-contradicting if
it contains, explicitly or implicitly, two assertions that are logically
incompatible with each other. Inconsistency can also occur between words
and actions. Example: A woman who represents herself as a feminist, yet
doesn't believe women should run for Congress.

22.NON SEQUITUR. ("It does not follow.") In this fallacy the premises
have no direct relationship to the conclusion. This fallacy appears in
political speeches and advertising with great frequency. Example: A
waterfall in the background and a beautiful girl in the foreground have
nothing to do with an automobile's performance.

23.QUESTIONABLE CAUSE. (In Latin: non causa pro causa, "not the cause of
that"). This form of the false cause fallacy occurs when the cause for
an occurrence is identified on insufficient evidence. Example: I can't
find the checkbook; I am sure that my husband hid it so I couldn't go
shopping today.

24.RED HERRING. This fallacy introduces an irrelevant issue into a
discussion as a diversionary tactic. It takes people off the issue at
hand; it is beside the point. Example: Many people say that engineers
need more practice in writing, but I would like to remind them how
difficult it is to master all the math and drawing skills that an
engineer requires.

25.SLANTING. A form of misrepresentation in which a true statement is
made, but made in such a way as to suggest that something is not true or
to give a false description through the manipulation of connotation.
Example: I can't believe how much money is being poured into the space
program (suggesting that 'poured' means heedless and unnecessary
spending)

26.STRAW MAN. This fallacy occurs when we misrepresent an opponent's
position to make it easier to attack, usually by distorting his or her
views to ridiculous extremes. This can also take the form of attacking
only the weak premises in an opposing argument while ignoring the strong
ones. Example: Those who favor gun-control legislation just want to take
all guns away from responsible citizens and put them into the hands of
the criminals.

27.TWO WRONGS MAKE A RIGHT. This fallacy is committed when we try to
justify an apparently wrong action by charges of a similar wrong. The
underlying assumption is that if they do it, then we can do it too and
are somehow justified. Example: Supporters of apartheid are often guilty
of this error in reasoning. They point to U.S. practices of slavery to
justify their system.