Chapter 5, Deep Analysis Video Solutions, Cengage Advantage Books: Understanding Arguments: An Introduction to Informal Logic

Problem 1

Put the following arguments into standard form and omit anything that does not affect the validity of the argument or the truth of its premises:
1. Philadelphia is rich in history, but it is not now the capital of the United States, so the U.S. Congress must meet somewhere else.
2. Not everybody whom you invited is going to come to your party. Some of them won't come. So this room should be big enough.
3. I know that my wife is at home, since I just called her there and spoke to her. We talked about our dinner plans.
4. I'm not sure, but Joseph is probably Jewish. Hence, he is a rabbi if he is a member of the clergy.
5. Some students could not concentrate on the lecture, because they did not eat lunch before class, although I did.
6. The most surprising news of all is that Johnson dropped out of the race because he thought his opponent was better qualified than he was for the office.
7. The liberal candidate is likely to win, since experts agree that more women support him.
8. It seems to me that married people are happier, so marriage must be a good thing, or at least I think so.

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Problem 2

Put the following arguments into standard form. Break up the premises and form chains of arguments wherever this can be done without distorting the argument. Then diagram the argument.
1. I know that Pat can't be a father, because she is not a male. So she can't be a grandfather either.
2. Either Jack is a fool or Mary is a crook, because she ended up with all of his money.
3. Our team can't win this Saturday, both because they are not going to play, and because they are no good, so they wouldn't win even if they did play.
4. Mercury is known to be the only metal that is liquid at room temperature, so a pound of mercury would be liquid in this room, which is at room temperature, and it would also conduct electricity, since all metals do. Therefore, some liquids do conduct electricity.
5. Since he won the lottery, he's rich and lucky, so he'll probably do well in the stock market, too, unless his luck runs out.
6. Joe is not a freshman, since he lives in a fraternity, and freshmen are not allowed to live in fraternities. He also can't be a senior, since he has not declared a major, and every senior has declared a major. And he can't be a junior, because I never met him before today, and I would have met him before now if he were a junior. So Joe must be a sophomore.
7. Since many newly emerging nations do not have the capital resources necessary for sustained growth, they will continue to need help from industrial nations to avoid mass starvation.

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Problem 3

In "A Piece of 'God's Handiwork"" (Exercise II in Chapter 4), Robert Redford argues that the Bureau of Land Management (BLM) should not allow Conoco to drill for oil in Utah's Grand Staircase-Escalante National Monument. The following passage is a crucial part where Redford answers an objection. Arrange its subarguments in standard form so as to reveal the structure of his argument. Then diagram the overall argument. The BLM says its hands are tied. Why? Because these lands were set aside subject to "valid existing rights," and Conoco has a lease that gives it the right to drill. Sure Conoco has a lease-more than one, in fact-but those leases were originally issued without sufficient environmental study or public input. As a result, none of them conveyed a valid right to drill. What's more, in deciding to issue a permit to drill now, the BLM did not conduct a full analysis of the environmental impacts of drilling in these incomparable lands, but instead determined there would be no significant environmental harm on the basis of an abbreviated review that didn't even look at drilling on the other federal leases. Sounds like Washington doublespeak to $\mathrm{me}^3$

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Problem 4

During the Republican candidates' debate on October 9, 2007, Chris Matthews asked Senator John McCain, "... Do you believe that Congress has to authorize a strategic attack, not an attack on-during hot pursuit, but a strategic attack on weaponry in Iran-do you need congressional approval as commander and chief?" Read McCain's response, then arrange its subarguments in standard form so as to reveal the structure of his argument. Then diagram the overall argument.
McCain: We're dealing, of course, with hypotheticals. If the situation is that it requires immediate action to ensure the security of the United States of America, that's what you take your oath to do, when you're inaugurated as president of the United States. If it's a long series of build-ups, where the threat becomes greater and greater, of course you want to go to Congress; of course you want to get approval, if this is an imminent threat to the security of the United States of America. So it obviously depends on the scenario. But I would, at minimum, consult with the leaders of Congress because there may come a time when you need the approval of Congress. And I believe that this is a possibility that is, maybe, closer to reality than we are discussing tonight. ${ }^4$

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Problem 5

Indicate whether each of the following arguments is valid and whether it is sound. Explain your answers where necessary.
1. Most professors agree that they are paid too little, so they are.
2. David Letterman is over four feet tall, so he is over two feet tall.
3. Lee can't run a company right, because he can't do anything right.
4. Barack Obama is smart and good-looking, so he is smart.
5. Barack Obama is either a Democrat or a Republican, so he is a Democrat.
6. Since Jimmy Carter was president, he must have won an election.
7. Since Gerald Ford was president, he must have won an election.
8. Pat is either a mother or a father. If Pat is a mother, then she is a parent. If Pat is a father, he is a parent. So, either way, Pat is a parent. (Assume that this conclusion is true.)
9. People who live in the Carolinas live in either North Carolina or South Carolina. Hillary Clinton does not live in North Carolina or South Carolina. Hence, she does not live in the Carolinas.
10. If all of Illinois were in Canada, then Chicago would be in Canada. But Chicago is not in Canada. Therefore, not all of Illinois is in Canada.

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Problem 6

Assume that the following sentences are either true (T) or false (F) as indicated.
All my children are teenagers. (T)
All teenagers are students. (T)
All teenagers are my children. (F)
All my children are students. (T)
Using these assigned values, label each of the following arguments as (a) either valid or invalid, and (b) either sound or unsound.
1. All my children are teenagers.
All teenagers are students.
$\therefore$ All my children are students.
2. All my children are students.
All teenagers are students.
$\therefore$ All my children are teenagers.
3. All teenagers are my children.
All my children are students.
$\therefore$ All teenagers are students.
4. All teenagers are students.
All my children are students.
$\therefore$ All my children are students.

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Problem 7

Indicate whether each of the following sentences is true. For those that are true, explain why they are true. For those that are false, show why they are false by giving a counterexample.
1. Every argument with a false conclusion is invalid.
2. Every argument with a false premise is invalid.
3. Every argument with a false premise and a false conclusion is invalid.
4. Every argument with a false premise and a true conclusion is invalid.
5. Every argument with true premises and a false conclusion is invalid.
6. Every argument with a true conclusion is sound.
7. Every argument with a false conclusion is unsound.

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00:26

Problem 8

There is one obscure exception to the premise that only a natural-born citizen may become president of the United States. The Constitution does allow a person who is not a natural-born citizen to become president if he or she was "a citizen of the United States at the time of the adoption of this Constitution." This exception is said to have been added to allow Alexander Hamilton to run for president, but it obviously does not apply to Schwarzenegger or to anyone else alive today. Nonetheless, this exception keeps the argument from being sound in its present form. Reformulate the final stage of the argument to make it sound.

Ashley High

Numerade Educator

Problem 9

The following arguments depend for their validity on suppressed premises of various kinds. For each of them, list enough suppressed premises to make the argument valid and also to show why it is valid. This might require several suppressed premises of various kinds.
EXAMPLE:
Carol has no sisters, because all her siblings are brothers.
SUPPRESSED Premises: A sister would be a sibling.
A brother is not a sister.
1. Britney Spears is under age thirty-five. Therefore, she cannot run for president of the United States.
2. Nixon couldn't have been president in 1950 because he was still in the Senate.
3. 81 is not a prime number, because 81 is divisible by 3 .
4. There's no patient named Rupert here; we have only female patients.
5. Columbus did not discover the New World because the Vikings explored Newfoundland centuries earlier.
6. There must not be any survivors, since they would have been found by now.
7. Lincoln could not have met Washington, because Washington was dead before Lincoln was born.
8. Philadelphia cannot play Los Angeles in the World Series, since they are both in the National League.
9. Mildred must be over forty-three, since she has a daughter who is thirtysix years old.
10. He cannot be a grandfather because he never had children.
11. That's not modern poetry; you can understand it.
12. Harold can't play in the Super Bowl, because he broke his leg.
13. Shaquille must be a basketball player, since he is so tall.
14. Dan is either stupid or very cunning, so he must be stupid.
15. Susan refuses to work on Sundays, which shows that she is lazy and inflexible.
16. Jim told me that Mary is a professor, so she can't be a student, since professors must already have degrees.
17. This burglar alarm won't work unless we are lucky or the burglar uses the front door, so we can't count on it.
18. His natural talents were not enough; he still lost the match because he had not practiced sufficiently.

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Problem 10

Reconstruct and diagram the main arguments in:
1. The passages at the end of Chapters 1 and 4.
2. An editorial from your local paper.
3. Your last term paper or a friend's last term paper.

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01:32

Problem 11

Not all arguments are serious or good. The following silly argument comes from a famous scene in Monty Python and the Holy Grail. Reconstruct the argument that is supposed to show that the woman is a witch.
CROwD: We have found a witch. May we burn her? ...
WOMAN: I'm not a witch! I'm not a witch! . . .
LEADER: What makes you think she is a witch?
MAN \#1: She turned me into a newt!
LEADER: A newt?
MAN \# 1: I got better.
Crowd: Burn her anyway!
LEADER: Quiet! Quiet! There are ways of telling whether she is a witch.
Crowd: Are there? What are they? Tell us. Do they hurt?
LEADER: Tell me, what do you do with witches?
Crows: Burn them!
LEADER: And what do you burn apart from witches?
MAN \#2: More witches!
MAN \#3: Wood.
LEADER: So, why do witches burn?
MAN \#1: 'Cause they're made of wood.
LEADER: Good! . . . So, how do we tell whether she is made of wood?
Crowd: Build a bridge out of her.
LEADER: Ah, but can you not also make bridges out of stone?
Crowd: Oh yeah.
LEADER: Does wood sink in water?
Crowd: No, it floats. Throw her into the pond!
LEADER: What also floats in water?
Crows: Bread. Apples. Very small rocks. Cider! Great gravy. Cherries. Mud. Churches. Lead.
ARTHUR: A duck!
LEADER: Exactly. So, logically, 一
MAN \#3: If she weighs the same as a duck, she's made of wood.
LEADER: And therefore?
Crowd: A witch! ... A duck. A duck. Here's a duck!
LEADER: We shall use my largest scales.
Crowd: Burn the witch! (Woman is placed on scales opposite a duck.)
LEADER: Remove the supports. (Woman balances duck.)
CROWD: A witch!
WOMAN: It's a fair cop.

Jiji Peter

Numerade Educator

Problem 12

What is the best argument that Justice Stewart could give in support of the premise that the death penalty "excessively go[es] beyond" what is necessary for any legitimate and worthwhile purpose? Is this argument adequate to justify this premise? (For one such argument, see Justice Brennan's opinion in Furman v. Georgia.)

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01:03

Problem 13

To solve a mystery, you need to determine which facts are crucial and then argue from those facts to a solution. Solve the following mysteries and reconstruct your own argument for your solution. These stories come from Five-Minute Whodunits, by Stan Smith (New York: Sterling, 1997). The first passage introduces our hero:

Even those acquainted with Thomas P. Stanwick are often struck by his appearance. A lean and lanky young man, he stands six feet two inches tall. His long, thin face is complemented by a full head of brown hair and a droopy mustache. Though not husky in build, he is surprisingly strong and enjoys ruggedly good health. His origins and early life are obscure. He is undeniably well educated, however, for he graduated with high honors from Dartmouth College as a philosophy major. ${ }^7$

Arwa Ali

Numerade Educator