1. Chapter 6
Relevance fallacies!
What you need to know…

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What is a fallacy?
An argument that doesn’t really support or prove what it is supposed to support or prove.
Still, it may seem convincing.
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3. What’s a relevance fallacy?
A ‘red herring,’ a distraction.
An argument that is not really relevant to its conclusion.
“You tell me it’s dangerous to text when I’m driving, but I have seen you doing it.”
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Ad hominem fallacies
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If a speaker or writer attempts to dismiss someone’s position by discussing the person rather than attacking his or her position, a fallacy is committed:
Argumentum ad hominem.
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6. Argumentum ad hominem is 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!”
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7. The only crock here is that argument! Why is it a fallacy?
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.
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8. In case you still don’t see it:
Issue: Is global warming the most serious threat?
Which of the following assertions is RELEVANT?
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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.
Al Gore spends $20,000 a year on electricity—NOT RELEVANT!
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10. Let’s look at some varieties of Argumentum ad hominem
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Abusive ad hominem
“What Al Gore says about air pollution is a joke! That clown will say anything to get attention!”
The speaker is simply bad-mouthing Mr. Gore.
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12. 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?”
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13. 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.”
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14. Three more kinds of ad hominem
Poisoning the well
Guilt by association
Genetic fallacy
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POISONING THE WELL
Trying to dismiss what someone is going to say, by talking about his/her character or circumstances or consistency.
“Senator Clinton is going to give a talk tonight on Iraq. Well, it’s just gonna be more baloney. That gal will say anything to get a vote.”
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Guilt by association
“You think waterboarding is torture? That sounds like something these left-wing college professors would say.”
Listeners are supposed to think calling waterboarding torture is “guilty” by virtue of its alleged association with supposedly left-wing college professors.
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GENETIC FALLACY:
Rejecting an idea because it came from a presumed defective source.
A fallacy that occurs when someone argues that the origin of a contention in and of itself automatically renders it false.
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GENETIC FALLACY
“Does God exist? Of course not. That idea originated with a bunch of ignorant people who knew nothing about science.”
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Compare:
GENETIC FALLACY:
“Does God exist? Of course not. That idea originated with a bunch of ignorant people who knew nothing about science.”
“John says God exists. What nonsense. He’s just saying that because he works for a church.”
Circumstantial ad hominem:
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20. Another famous fallacy:
THE STRAW MAN
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STRAW MAN
We are witnessing a Straw Man fallacy when a speaker or writer attempts to dismiss a contention by distorting or misrepresenting it.
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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!”
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New fallacy!
FALSE DILEMMA
Also known as Black/White; Either/Or; All/Nothing; Ignoring Other Alternatives
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The False Dilemma fallacy happens when someone tries to establish a conclusion by offering it as the only alternative to something we will find unacceptable, unattainable, or implausible.
“Either we allow the oil companies to drill for oil in the Gulf or we will be at the mercy of OPEC. Therefore we shouldn’t prevent the oil companies from drilling for oil in the Gulf.”
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FALSE DILEMMA
Example:
“Either we increase the number of troops in Iraq or the terrorists will be attacking U.S. cities. Seems like a simple choice to me.”
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26. “PERFECTIONIST” version of false dilemma
Example:
“It’s impossible to eliminate terrorism entirely. We should stop wasting money on it.”
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27. “LINE-DRAWING” version of false dilemma
Example:
“ There shouldn’t be restrictions on violence in the movies. After all, when is a movie ‘too violent’? You can’t draw a line.”
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Two more famous twins:
MISPLACING THE BURDEN OF PROOF
BEGGING THE QUESTION
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29. MISPLACING THE BURDEN OF PROOF
This fallacy occurs when an attempt is made to support or prove a point by trying to make us disprove it.
“Obviously, the president’s birth certificate is a forgery. Can you prove it isn’t?”
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30. MISPLACING THE BURDEN OF PROOF:
Example:
“Can I prove the Biblical flood really happened? Hey, can you prove it didn’t???”
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Appeal to Ignorance
This is a variation of the fallacy of Misplacing the Burden of Proof.
It occurs when it is argued that we should believe a claim because nobody has proved it false.
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BEGGING THE QUESTION
This fallacy occurs when a speaker or writer tries to “support” or “demonstrate” a contention by offering as “evidence” or “proof” what amounts to a repackaging of the very contention in question.
“Obviously the president told the truth about Benghazi. He wouldn’t lie to us about it.”
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BEGGING THE QUESTION
Another example:
“Can I prove the Biblical flood really happened? Of course it happened! Why else would Noah build an ark???”
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34. What all these fallacies have in common:
They don’t demonstrate their conclusion.
They don’t support their conclusion (they don’t make their conclusion more likely).
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35. Appeal to Emotion & Irrelevant conclusions
Next:
Appeal to Emotion & Irrelevant conclusions
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