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8.12: Exercises

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    ■ 1. Label the fallacy committed by the district attorney in the following passage, and

    rewrite it to remove the fallacy.

    Will you tell the jury where you bought the gun used to shoot the liquor store clerk? Just a simple "yes" or "no" please.

    ■ 2. Create an ad hominem fallacy in your response to the following:

    I don't think it's appropriate at all to celebrate Columbus Day. The holiday honors a man who was responsible for the destruction of millions of Indians. People think Christopher Columbus was a good man, but he wasn't. We opened our arms to welcome him, but he took the land from us.

    3. Create a believable dialogue between two people in which the first person uses a non sequitur. Make the non sequitur be a serious argument, not a silly one. Have the second person point out the fallacy, and have the first person agree and correct the error in a way that now does make the point that was originally intended. Begin with a helpful description of the situation by giving background information to aid the reader in understanding the issue involved.

    4. Suppose I decide not to buy a television set today because my horoscope says it is a bad day for buying anything. I have a reason for not buying the TV set, but is my reasoning a non sequitur?

    5. Does the following argument use a fallacious appeal to authority? Why?

    Glass is mostly silicon atoms that slow the speed of light down to 122,000 miles per second. I know this because I overheard one of the employees at the science museum say so. I think it was the Assistant Director.

    ■ 6. Suppose you notice a webpage containing a news article headlined “SCIENTIFIC RESEARCHER CLAIMS LITTLE GIRL CAN CONTROL DICE WITH HER MIND.” The article reports on an investigation performed by a parapsychologist who examined a ten-year-old girl who said she could predict the outcome of rolling two dice, provided she rolled the dice. In response to that article, a friend of yours says, “I am not going to be influenced by that silliness. The parapsychologist is a well-known member of a far right political organization, and she once posed nude for Playboy magazine.” This response from your friend is an example of

    1. an ad hominem fallacy
    2. a fallacious appeal to authority
    3. a false dilemma
    4. a slippery slope

    7. Is a fallacious appeal to authority committed in the following argument for the conclusion that men are naturally better at basketball and weightlifting?

    John: Men make better basketball players than women do. I would say the same about weightlifting, too.

    Sarah: Yes, I agree. You rarely see women competing in these sports. However, someday, when interests change, women will be as good as men.

    John: Oh, no, I wasn't clear. I mean that men will always be better, because men are just naturally better at these sports. Average men will be better than average women, and the best men will be better than the best women.

    Sarah: What makes you say this?

    John: I’ve consulted an expert, that's why.

    Sarah: Oh yeah, who?

    John: My mother.

    Sarah: Ha! Your mother. Who's your mother?

    John: She was a coach.

    Sarah: So?

    John: She's athletic director at a women's college; she once was hired by a state university to scout high school basketball players, men and women, for potential athletic scholarships; she is a specialist in sports physiology; and she has carefully followed basketball and weightlifting at all levels of the sports. She even wrote an article about all this for Sports Illustrated magazine.

    Sarah: Well, that may be true about her, but I still think that women could be as good as men if they just had an equal chance.

    John: No way. Women are hopeless. They should not even be allowed to try out.

    8. Create an original paragraph that uses a believable but fallacious appeal to authority.

    ■ 9. Create an original example of the straw man fallacy in response to the following argument:

    I urge you to join the campaign for the proposal. This initiative proposal is in circulation under the tide "Law Invalidation." It is an initiative constitutional amendment, sponsored by two private citizens, that seeks to abolish the California State Bar Association. This leaflet shows you that ten prominent attorneys support the proposal.

    10. Suppose Jones argues for some point x. Suppose x is attacked by Smith for two reasons: x implies y, and y is incorrect. If Smith is correct about both reasons, his argument is

    a. a straw man

    b. an ad hominem

    c. avoiding the question

    d. not fallacious

    e. irrelevant to the issue of whether x is so.

    11. State how to go between the horns of the following dilemma. Ignore the loaded language.

    I understand what you are saying about business ethics, but you need to see it from the businessperson's perspective. The choice in business is simple: either I adopt a vow of poverty and go for sainthood, or I take the more sensible path of maximizing personal income no matter what.

    12. Create a straw man fallacy in your response to the passage in Exercise 2 about Columbus Day, and then explain why your response deserves to be called an example of that fallacy.

    ■ 13. Which choice below is a single horn of the false dilemma created by the speaker?

    There are no black women conductors of major American symphony orchestras. I can guess why. Either black women aren't musical, or else God wanted no black women conducting those orchestras. But we all know there are some black women who are musical, so I guess it's all part of God's plan.

    a. God wanted there to be no black women conductors of major American symphony orchestras.
    b. There are no black women conductors of major American symphony orchestras.
    c. Black women are musical.
    d. Either black women aren't musical, or else God wanted no black women conducting those orchestras.

    14. You will commit the fallacy of faulty comparison if you

    a. compare apples with tangerines and then say that the cost per pound of one is outrageously high in comparison with the cost per pound of the other.
    b. fail to compare apples that you are offering for sale with apples that are rotten.
    c. compare apples with oranges and fail to consider that at current prices, two apples equal one orange in California but not in New York.
    d. promote the health value of your own apples over the competition's apples by comparing the health of eaters of your apples with people who eat no fruit at all.
    e. say that Jones & Jones gloves are best for protecting gardener's hands on the basis of a comparison between those gloves and other means of hand protection, including the competition's gloves.

    15. Is the fallacy of faulty comparison committed in the text of this 1950s magazine advertisement?

    MORE DOCTORS SMOKE OUR CIGARETTE. Check for yourself-smoke our cigarette and see if you don't get less throat irritation.

    ■ 16. What fallacy, if any, is committed here?

    Physicist Jones won the Nobel Prize for his advances in astronomy. Physicist Jones says Republicans are ruining the economy. So, Republicans are probably ruining the economy.

    17. Which fallacy, if any, occurs in the following piece of reasoning?

    I left my car keys in the house. I’ve looked carefully all over the bedroom for my car keys and failed to find them. Therefore, I left them in some other room.

    a. fallacious appeal to authority
    b. ad hominem
    c. avoiding the question
    d. straw man
    e. false dilemma
    f. none of the above

    18. What is the best characterization of the following passage?

    As of January 23, 1977, 88 percent of all U.S. homes had at least one TV set. As of January 23, 1987, 77 percent of all U.S. homes had at least one color TV set. So, as of January 23, 1997 nearly 66 percent of all U.S. homes will have a cell phone.

    a. straw man
    b. fallacious appeal to authority
    c. ad hominem
    d. non sequitur
    e. no fallacy occurs here; it's fine reasoning

    19. During a heated battle in an earlier century, a Prussian emperor, whose troops were displaying fear, urged his men forward with "Onward! What do you want? Do you want to live forever?” Identify a false dilemma here. What is a reasonable way for a Prussian soldier to escape between the horns of this dilemma? First, explicitly define the dilemma. (Hint: The dilemma is not between living and dying, nor between obeying and disobeying.)

    ■ 20. The verb go is conjugated in the present tense as I go, you go, he goes. Bertrand Russell once said that something can be learned from the correct conjugation of words. For example, he conjugates the word firm this way: I am firm; you are obstinate; he is a pig-headed fool. What point is Russell really making?

    ■ 21. Comment on the quality of this argument:

    Microorganisms are small living creatures that can be seen only through a microscope. Bacteria, yeast, and molds are the three most important microorganisms in food fermentation. Therefore, the most important microorganisms in food fermentation are bacteria, yeast, and molds.

    22. Comment on the quality of the following reasoning and give a justification for your comment.

    Listen, Jerry. You’ve been convicted twice of molesting children, so your reasons for why the new child-care center should be built near your house aren't going to be acceptable to this committee.

    23. What fallacy or fallacies, if any, are committed in the following passage?2

    The scientific method simply sets a rigorous yet easily communicated standard for communicating information.... Before a scientist can accept a phenomenon as conclusively proven, several things must happen: First, the experiment must be designed so that no other factors can account for the result. A psychic may correctly identify all the cards in a Zener deck [a set of symbols used for testing telepathy]—but if the cards were so thin they could be read through their backs (as has happened), the experiment doesn’t prove anything. The scientist also demands that findings should be repeatable by other scientists in other locations following the same methods. If not repeatable, the result is not conclusive. Now apply these standards to the case of the paranormal. Scientific tests going back more than a century have shown a resounding inability to provide solid evidence for the existence of telepathy, clairvoyance, psychokinesis [moving things by mind power], precognition [seeing the future], levitation, reincarnation, transmigration [of souls], or miraculous healing.

    ■ 24. Juan argued that bluegrass is the best food for cattle in the Midwest. Sammy objected by citing how the authorities at the U.S. Department of Agriculture recommended alfalfa over bluegrass for Midwestern cattle. If Juan counters this objection by arguing that the U.S. Department of Agriculture is a bloated bureaucracy with too much fat that deserves to be cut in the next federal budget bill, then Juan has

    a. committed a fallacious appeal to authority.
    b. committed a false dilemma fallacy.
    c. committed the fallacy of avoiding the issue.
    d. refuted Sammy’s position.

    25. Imagine what somebody might say who sincerely disagrees with one of your own beliefs. Construct a 300 to 500-word argument that gives reasons for why your belief is incorrect. That is, argue for the other side of the issue. Begin by stating the issue. The new argument must contain no fallacies and no loaded language.

    26. Revise the sentence below to correct the errors:

    In the Dark Ages, people lived in a world free of diseases from microorganisms, because the germ theory of disease wasn’t discovered yet.

    ■ 27. Examine the following conversation and look for a fallacy in the reasoning:

    Mother: My fifteen-year-old daughter failed two courses at school. The worst part is, she didn't even try. She just said, "Oh well, it's not important." If she had tried and failed, that wouldn't be so bad.
    Friend: Are you sure it wouldn't be so bad? Maybe it would be worse if she tried and failed.
    Mother: No, it wouldn't, because if she tried she probably wouldn't fail the two courses.
    Friend: Oh, I think I see what you mean. Do you mean that anybody who tries will succeed at least in the sense that they did try and didn't just give up?
    Mother: No, I just mean that if my daughter tries, she most likely will get a grade higher than an E.

    Who made the error, the mother or the friend? What error?

    28. Revise the dialogue above between the mother and her friend so that it no longer commits the fallacy.

    29. Create an ad hominem fallacy in your response to the following argument:

    Our department could use the new MouseMan mouse. Since it doesn't use a wire connected to the computer, buying it won't cause more desk clutter. Also, it doesn't have the annoying electrical interference problems that plague other infrared cordless mice. And new MouseMan "sleeps" when you're not working, so a common battery lasts up to a year inside of it. Sounds perfect to me. Let's order a batch of these mice.


    1 This is a black-white fallacy. An innocent person would have a tough time finding an answer if the question were taken literally. The defendant could escape the two unpleasant choices by saying, "Hey, I never bought any gun, and I never shot the clerk." This defense via pointing out a third possibility besides the two unpleasant ones is called "escaping between the horns of the dilemma." The D.A. should not have required a simple yes or no answer. To remove the fallacy, you could make a variety of changes; the easiest is to say, "Did you shoot the clerk?" followed by "Did you buy a gun?" An acceptable question would be "Just a simple yes or no: did you buy the gun used to shoot the liquor store clerk?" It is not really sufficient to rewrite the question as: "Will you tell us where you bought your gun?" Assuming

    2 "Hey, you are wrong about Columbus Day; you're some sort of bleeding heart liberal, so your word cannot be trusted." The personal attack alone isn't enough to make the fallacy; you must also suggest that this attack somehow shows that the person's reasoning is unreliable. Here is a different sort of ad hominem fallacy: "What do you know about Columbus Day? You and everyone else in your radical organization are out to smear the good name of white people." This latter kind of ad hominem fallacy is called the fallacy of guilt by association, because the reasoner is said to be guilty of error because of groups he or she associates with.

    6 Answer (a). This is an attack on the reasoner rather than on the reasoner’s reasoning.

    9 Here is one of many ways to create the straw man fallacy:

    The arguer is asking you to join in holding up our lawyers and judges to public ridicule. This is a simple witch hunt, like that in Puritan New England hundreds of years ago. Do you really want to engage in this sort of disgraceful behavior? Hasn't our society lifted itself above the narrow intolerance of the past?

    13 Answer (a). The two horns of this dilemma are stated in choice (d). Choice (a) expresses just one horn of that dilemma.

    16 Appeal to inappropriate authority. In this argument, so is a conclusion indicator term, and the conclusion is preceded by two almost irrelevant reasons.

    20 First, notice that Russell is making a joke. He is not committing the ad hominem fallacy, nor is he making a point about conjugation. The serious point behind the joke is that we don't judge others by the same standards that we judge ourselves. The more distant the actor is from us, the more likely we are to see the fault in the action. Therefore, this passage offers an example of how reasoners (other than Russell) often do not treat the issue fairly.

    21 The conclusion, which is signaled by the conclusion indicator term therefore, is just a restatement of the reason for the conclusion. The conclusion does not "go anywhere." Logicians call this kind of fallacy circular reasoning.

    24 Answer (c). Choice (b) is incorrect because Juan’s attack on the U.S. Department of Agriculture is not an attack on the arguer.

    27 The error was made by the mother. She did not respond to her friend's question about whether it would be worse for the daughter to try yet get an F than not to try at all. Therefore, the mother committed the fallacy of avoiding the question, regardless of whether she avoided it on purpose or simply didn't get the point of the question

    This page titled 8.12: Exercises is shared under a CC BY-NC-SA license and was authored, remixed, and/or curated by Bradley H. Dowden.

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