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PART THREE: OTHER SYSTEMS OF LOGIC
EXERCISE 15 1:
(One person’s opinions, provided with a great deal of hesitation. More important is how
students answer these questions. )
1. Begging the question: The question was whether her suspicions were correct.
17. Begging the question: The person in question knew very well that saliva is what
makes the mouth normally wet, and salivary glands are what produce saliva. She
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23. Denying the antecedent: The executive is reasoning: If we don’t lower our prices
then we will lose money. We do lower our prices. So we won’t lose money.
25. Inconsistency: In a modern primarily urban society such as exists in Israel, most
people don’t raise their own meat but have to buy it from retail stores; so if these
stores were not allowed to sell meat from the pig, this means that most people in
Israel in effect would be forbidden to eat that sort of meat.
27. Non sequitur: What does being on sale have to do with whether or not it was
33. Inconsistency: It’s unlikely that we were neutral on the outcome if we provided
EXERCISE 15 2:
(Again, answers are provided hesitantly.)
1. Questionable analogy: Of course, philosophers and theologians have been
arguing about this one for thousands of years. (But it is questionable! )
3 . Slippery slope: In fact, the Panama Canal was (slightly) at risk as this was
written, but the reasons had nothing to do with what was going on in El Salvador,
or Nicaragua for that matter.
5. Questionable cause (or slippery slope): Overcrowding is bad, but golly gee, it
isn’t what makes kids use drugs. It doesn’t start in motion a series of events
leading to drug taking, or even gang violence, it just increases the likelihood of
less learning.
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9. Questionable analogy (and suppressed evidence): The point of the ad was to
minimize the damage and wrongness of the Valdez oil spill. But the comparison is
11. False dilemma (or tri lemma?).
13 . Inconsistency: The writer is for freedom of speech, but not the freedom to say
17. Suppressed evidence: These are all places where anyone is more likely to be at
21. Questionable cause: The implication of her remark is that being homosexual
causes Bible burning (or perhaps small sample, based on one case of such bible
23. Questionable cause: One hundred percent of all those who use heroin started out
on milk. So what? The overwhelming majority of those who have smoked
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27. Questionable analogy: knowledge of the relevant aspects of a motor accident
29. Provincialism: Considering one’s own system to be so much superior to the other
31. Begging the question: The patient wants to know whether he will recover and is
told he will, unless he won’t.
41. Hasty conclusion: Reagan’s remark was pertinent, given that the errors of past
administrations could not be instantly rectified during his. But given that his
43. Common practice (or appeal to authority of the “loftiest souls” who perpetrated
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45. No Fallacy: There is a common diplomatic practice involved here, but adhering
47. Equivocation: Nonexistence is a something in that it can be talked about,
55. Faulty comparison (and suppressed evidence): There are lots more than twenty
57. Questionable analogy: We think of people as different from other animals. Or
59. The intended answer was begging the question. She does seem to have admitted
EXERCISE 15 3:
(Not appropriate to answer. )
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EXERCISE 16 1:
1. Increase strength: a, since increases relevant similarities; Neutral: d, since day of
the week seems to be irrelevant, also e, since it seems that the color of the movie
3. Increase strength: b, since lessens the possible relevant dissimilarities between the
EXERCISE 16-2:
1. Weak analogy: Some desires (such as for food or sex) are often not satisfied in
this life; some (such as for peace of mind or ecstasy) are rarely satisfied; and
EXERCISE 16 3:
1. Both are observable.
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EXERCISE 16 4:
1. Agreement and difference
9. Agreement (negative)
EXERCISE 16-5:
EXERCISE 16-6:
3. P(p q) = P(p)P(q)
5. a. Probability of seven on a toss = 6/36 = 1/6. Probability of two sevens in a row
9. a. Probability of an ace on a draw = 1/13