Chapter 6
Fallacies involving Relevance:
A fallacy is a common mistake in reasoning where people
take the argument to be good when it is irrelevant.
The Straw Man Fallacy:
Criticizing a weak or mistaken version of a person’s
argument and claiming the real position is flawed is to
commit the straw man fallacy. The reason it is a
relevance fallacy is because the weak and mistaken
version of the argument is not relevant for criticism.
STRAW MAN
• Example:
• “Twenty percent? You want to tip her
20%???? Hey, maybe you want to give
her everything we make, but I frankly
think that is ridiculous!”
STRAW MAN
If the advocates for prayers in public schools win on this
issue, just where will it end? Perhaps next they will ask for
prayers on public transportation? Prayers by government
workers before they start their job each day? Or maybe,
mandatory prayers in public restaurants before starting
each meal might be a good idea.
Chapter 6
The ad hominem fallacy:
The ad hominem fallacy occurs when a critic attacks a
person instead of arguing against the claims that the
person has put forth.
It is a relevance fallacy because attacking the person is not
relevant to the rational acceptability of the premises of
the argument.
Ad hominem literally mean “against the man.”
Argumentum ad hominem: the
most common fallacy on
earth.
 Example:
“According to Al Gore, global warming is
the most serious threat facing us today.
Folks, what a crock. Al Gore spends
$20,000 each year on electricity in his
Tennessee mansion!”
Why is this fallacious?
• Look at it logically:
• Premise: All Gore spends $20,000
each year on electricity.
• Conclusion: Therefore global warming
is not the most serious threat facing us
today.
In case you still don’t see it:
• Issue: Is global warming the most serious threat?
Which of the following assertions is RELEVANT?
• GW will cause rising sea levels to swamp all east
coast cities by 2100.
• GW will cause coral reefs to die within 30 years.
• CO2 levels have risen over 30% in the last 25 years,
due to GW.
• According to a study published in Nature, current
rates of warming will lead to extinction for 1 million
species by 2050.
• All Gore spends $20,000 a year on electricity—NOT
RELEVANT!
ATTACK ad hominem
• “What Al Gore says about air pollution is
a joke! That clown will say anything to
get attention!”
CIRCUMSTANTIAL ad
hominem
• “What Al Gore says about air pollution is
pure bull. Al Gore makes a fortune from
alternative energy investments. What do
you think he’d say?”
• "I think that we should reject what
Father Jones has to say about the
ethical issues of abortion because he is
a Catholic priest. After all, Father Jones
is required to hold such views."
Chapter 6
Another kind of ad hominem fallacy is the circumstantial ad
hominem fallacy are the tu quoque fallacy.
Tu quoque literally mean “you too” and it to object to a view
or advice from a person because the person doesn’t
adhere to the advice. Consider this dialogue:
Mom: Don’t smoke; it is bad for you.
Daughter: But mom you smoke, so I should be able to.
The daughter’s reply is irrelevant to the advice and is thus
an instance of the tu quoque fallacy. (page 157 for more
examples)
INCONSISTENCY ad
hominem
• “Senator Clinton says we should get out
of Iraq. What a bunch of garbage
coming from her! She voted for the war,
don’t forget.”
Chapter 6
There is one issue that we should watch for with ad
hominem arguments. Sometimes when you attack the
person, it is RELEVANT. If attacking the person is
relevant to the argument, then it is not an ad hominem
fallacy. Consider this example,
Charles says to buy his diet pills, they work, he uses them.
If Charles has gained weight while on the pills, it is okay to
attack him for the claims made as long as it is relevant to
his claims.
Chapter 6
The Fallacy of Guilt by Association:
This fallacy of guilt by association is committed when a
person or his or her views are criticized on the basis of a
supposed link between that person and a group or
movement believed to be disreputable.
When the association is not relevant, we have another
relevance fallacy.
The fallacy of virtue by association claims goodness
instead of guilt, but is still irrelevant.
Guilt by Association
From Fallacies Files:
The al Qaeda Cheering SectionThe most telling
moment in last night's [State of the Union] speech
came after the president noted that "key provisions
of the Patriot Act are set to expire next year." In
response, notes the New York Times, "some critics
in Congress applauded enthusiastically." If Osama
bin Laden watched the speech, one imagines him
applauding too.
From Fallacies Files:
Analysis of the Example:
That Osama bin Laden might approve of the
expiration of provisions of the Patriot Act does
not show that American critics are wrong to also
approve, since the reasons for their approval
are different. Some Americans oppose parts of
the Patriot Act because they believe that it
infringes upon the rights of Americans without
significantly helping to prevent terrorism. They
may be wrong, but that doesn't make them an al
Qaeda cheering squad.
Chapter 6
Fallacious Appeals to Popularity
The appeal to popularity occurs when people seek to infer
merit or truth from popularity. It is also know as the
bandwagon fallacy or its Latin name, ad populam.
It the issue in question is not the sort of thing that can or
should be decided by popularity, then an ad populam
fallacy has been committed.
“Argument” from Popularity
“Everybody believes X.
Therefore X is true.”
Examples:
•“Everybody thinks God exists.
Therefore, God exists.”
•Of course you want to buy Crest
toothpaste. Why, 90 percent of America
brushes with Crest!
Chapter 6
Fallacy of Appeal to Ignorance (ad ignorantiam)
An argument exemplifies a fallacious appeal to ignorance if
and only if the premises describe ignorance, lack of
confirmation, lack of proof, or uncertainty regarding a
statement S; and a conclusion about the truth or falsity
or probability or improbability of S, or a further statement,
is inferred simply on the basis of this ignorance. From
ignorance we can infer only lack of knowledge. We
cannot infer truth or falsity or objective probability or
improbability.
Appeal to Ignorance
• [Joe McCarthy] announced that he had
penetrated "Truman's iron curtain of secrecy"
and that he proposed forthwith to present 81
cases… Cases of exactly what? "I am only
giving the Senate," he said, "cases in which it is
clear there is a definite Communist
connection…persons whom I consider to be
Communists in the State Department." … Of
Case 40, he said, "I do not have much
information on this except the general statement
of the agency…that there is nothing in the files
to disprove his Communist connections."
Chapter 6
The Burden of Proof:
Often a fallacious appeal to ignorance is an attempt to
shift the burden of proof (or argumentative onus) onto
the other person in the debate.
The idea of burden of proof is one that will vary from
context to context, but attempting to shift the burden with
relevance fallacies are also just justified.
MISPLACING THE BURDEN
OF PROOF
• Example:
• “Can I prove the Biblical flood really
happened? Hey, can you prove it
didn’t???”
Examples of Burden of Proof
Bill: "I think that we should invest more money in
expanding the interstate system."
Jill: "I think that would be a bad idea, considering the state
of the treasury."
Bill: "How can anyone be against highway
improvements?"
Bill: "I think that some people have psychic powers."
Jill: "What is your proof?"
Bill: "No one has been able to prove that people do not
have psychic powers."
"You cannot prove that God does not exist, so He does."
BEGGING THE QUESTION
• Example:
• “Can I prove the Biblical flood really
happened? Of course it happened! Why
else would Noah build an ark???”
Examples of Begging the Question
Bill: "God must exist."
Jill: "How do you know."
Bill: "Because the Bible says so."
Jill: "Why should I believe the Bible?"
Bill: "Because the Bible was written by God."
Interviewer: "Your resume looks impressive but I
need another reference."
Bill: "Jill can give me a good reference."
Interviewer: "Good. But how do I know that Jill is
trustworthy?"
Bill: "Certainly. I can vouch for her."
Red Herring/Smokescreen
• An irrelevancy brought in to “support” a
claim or to distract one from the issue
• Technically, many are Red Herrings.
• But we will use “Red Herring” to refer to
irrelevancies we cannot put into one of
our other categories.
We will make no distinction between a
“Red Herring” and a “Smoke Screen”
Example of a Red Herring:
“Yes, of course the President’s strategy in
Iraq is working. The Democrats sure
haven’t come up with anything better!”
Another example of Red Herring
• “Yes, obviously the President’s strategy in
Iraq is working. The liberal media in this
country just can’t stand the thought of us
winning this war.”
• It’s also a Red Herring if you change the
subject to avoid answering a question:
• “Why do I oppose gay marriage?
I guess it was the way I was brought up.”
Chapter 6
Additional Relevance Fallacies:
Trying to provide a categorization of all relevance fallacies
would be long and not particularly useful. But there are
two more general irrelevances that people use: fear and
pity.
The appeal to pity’s Latin name is: ad misericordiam.
The appeal to fear’s Latin name is: ad baculum.
These are fallacies when fear and pity are used to argue
and are irrelevant to the conclusion.
Examples of Appeal to Pity
Jill: "He'd be a terrible coach for the team."
Bill: "He had his heart set on the job, and it would
break if he didn't get it."
Jill: "I guess he'll do an adequate job."
"I'm positive that my work will meet your
requirements. I really need the job since my
grandmother is sick"
"I should receive an 'A' in this class. After all, if I don't
get an 'A' I won't get the fellowship that I want."
Web Sites on Fallacies
http://www.fallacyfiles.org/
http://www.nizkor.org/features/fallacies/
https://yourlogicalfallacyis.com/