2.15: Exercises

General Exercises

1. If two people disagree with each other, then one of them is not a critical thinker.

a. true
b. false

2. According to the U.S. Department of Agriculture's Food and Drug Administration, the four major food groups are corn, pork, beer, and Jell-O salad with marshmallows. Which food group is preferred by future Italian diplomats?

a. corn
b. pork
c. beer
d. Jell-O salad with marshmallows.

3. Consider each of the following four sentences and say whether they would typically be used to make a statement or not to make a statement:

Where is it? There it is! Watch out! It's coming toward us too fast!

4. Ok, you math geniuses, a farmer had 17 sheep, and all but 9 died. Then the farmer was given 2 from his brother but both died. How many of the farmer's sheep were left? [Hint: Not 8.]

5. Briefly describe what is going on in the following paragraph by answering these questions: What is its main purpose? Is there an argument? Is anything explained? What? Is there any description? The paragraph is about Catherine the Great’s wedding in Russia in 1745. She was a sixteen-year-old bride-to-be of the seventeen-year-old future emperor.

Detecting Single, Explicit Arguments

■ 1. What is the conclusion indicator term in this argument?

If it rains, then it’s a bad time for a picnic. So, we shouldn’t go there for a picnic since Svetlana knows it’s raining there now. At least that’s what she heard.

a. If
b. Then
c. So
d. We shouldn’t go there for a picnic
e. None of the above

■ 2. What is the premise indicator term in this argument?

We already know the solution to Rafael’s third math problem is a number which is divisible by 8. I think the answer is probably 32. At any rate, we can suppose that for any number, if it is divisible by 8, then it is divisible by 16. So, the solution to his third problem is divisible by 16. Isn’t 32 divisible by 16?

a. I think
b. at any rate
c. we can suppose that
d. if
e. so

■ 3. Which sentence below probably is not being used to make a claim (that is, a statement)?

a. I wonder if we should turn back.
b. Financial ruin from medical bills is almost exclusively an American disease.
c. I learned a long time ago that minor surgery is when they do the operation on someone else, not you.
d. My bumper sticker asks, “Do you believe in love at first sight, or should I drive by again?”

■ 4. Identify all the conclusion indicators and premise indicators, if any, in the following passage:

The Philadelphia company’s letter said they would place their call to us here in Los Angles at 2pm their time. They are in a time zone that is three hours east of us; therefore, we should expect their call at 11am our time, but if they don’t call then let’s go to plan B.

■ 5. The sentence below is quite likely

a. an argument or explanation
b. neither an argument nor an explanation

Dynamic Random Access Memory (DRAM) chips were once the popular choice for memory storage on personal computers since, unlike the SRAM chip, they were less expensive per byte and the DRAM design essentially required using only one transistor per bit.

■ 6. The following passage contains

a. an argument
b. a report of an argument
c. neither

Through a process of trial and error, early people slowly learned that some contaminated food made them sick, while other contaminations improved the flavor, made an exhilarating fruit drink, or helped preserve the food for longer periods of time. In modern times, scientists learned that the contaminations are due to bacteria, yeast, and molds.

7. The sentence below is quite likely

a. an argument
b. not an argument

The life of a respected technical professional has few spare moments because there's all that work from running labs to teaching to speaking at colloquiums to writing grant proposals to selling research programs to administrating or managing to maybe even finding a few minutes to think about what to do.

■ 8. Which are the premise indicators in the following list?

if, then, yet, nevertheless, on the contrary, but, thus, suppose that

■ 9. Which are the conclusion indicators in the following list?

if, then, yet, nevertheless, on the contrary, but, thus, suppose that

■ 10. Does this argument contain any premise indicators that are working to indicate premises? If so, identify them.

President Kennedy was smart to have approved the Bay of Pigs invasion of Cuba in 1961 since he could be reasonably certain the USSR wouldn't physically intervene to help Cuba, and since he wanted to do something that could overthrow the left-wing government.

11. Is the word since working to indicate a premise or conclusion in the following?

Since 5 p.m. I’ve been hungry.

12. Add a premise indicator, remove the conclusion indicator (without replacement), and rewrite the following argument as a single sentence.

Ever since the inflationary spiral ended, state taxes have been high. State farm subsidies will therefore continue to rise.

13. Is the word suppose working as a premise indicator in the following?

I suppose you're right that the New York Giants have a better passing game than the L.A. Rams.

14. Add a premise indicator, remove the conclusion indicator (without replacement), and rewrite the following argument as a single sentence.

The average length of an ear of popcorn has been longer ever since the 2010 planting regulations were adopted. State sales of popcorn will therefore continue to prosper.

■ 15. Is this really a statement?

Ah, America, the land of catastrophic wealth imbalance, may its flag ever wave.

■ 16. Consider the following argument:

All those containers contain petroleum since each one has a blue top and all petroleum containers have blue tops.

Let ...

A = All those containers contain petroleum.
B = Each of those containers has a blue top.
C = All petroleum containers have blue tops.
D = Everything with a blue top is a petroleum container.

Which one of the following would be a symbolic representation of the argument in standard form?

17. Is the argument in the previous question deductively valid?

■ 18. Does the following contain an argument, and if so what are its conclusion and premises?

By the age of seven, Snow-White had grown more beautiful than her stepmother, the Queen. Then the Queen asked her mirror: “Mirror, mirror on the wall, Who is the fairest of us all?” and it answered: “Queen, thou art the fairest in this hall, But Snow-White's fairer than us all.” Horrified, the envious Queen called a royal hunter and said: “Take the child into the forest. Kill her, and bring me her lung and liver as a token.” ^[52]

19. Which of the following sentences contain explicit argumentation—that is, explicitly contain the two elements required to be any argument (a conclusion plus one or more premises)?

a. Among all creatures, humans are distinguished by the extent to which they wonder about things that do not immediately affect their subsistence.
b. Every man is a potential killer, even if he believes otherwise. What I mean to say is, every man is capable of taking a life. And man is not the only creature on Earth who is a potential killer.
c. If you were to pick an apple at random from that basket, then you'd probably get one without a worm in it.
d. Stop right there, Jack; it's not raining today, so you won't need to take that umbrella. Put it back.

20. The following passage is most likely

a. an argument
b. not an argument

Although rattlesnakes are the most common poisonous snake in North America, there are four types of poisonous snakes on the continent: rattlesnakes, copperheads, moccasins, and coral snakes. The first three belong to the pit viper group, and the most reliable physical trait by which to identify them is the pair of pits between the eye and the nostril. These pits are heat sensitive and allow the snake to sense its prey. Keep in mind that a snake's venom is designed for catching food, not attacking people.

■ 21. Is the following passage an argument? Why or why not?

If you get lost in the woods and no one responds to your calls, walk downhill until you come to a stream. Then walk downstream; you'll eventually come to a town.

■ 22. Identify the discount claim and the discount indicator in the following passage.

Svetlana came over this afternoon in an even worse state than this morning. She is so mad at Li that I worry what she’s going to do. She asked for the knife back that she loaned us. I realize that we did promise to give it back soon, but she’s so agitated right now that, if we return it, I think she’s going to use it on Li. So, let’s lie to her and say we can’t seem to find the knife.

23. What is the role of the last sentence in the argument of this passage?

If it rains, then it’s a bad time for a picnic. So, we shouldn’t go there for a picnic since Svetlana knows it’s raining there now. At least that’s what she heard.

24. Identify the implicit conclusion in this argument:

Robert Smalls was assigned to the slave crew of a Confederate ship at Charleston, South Carolina during the U.S. Civil War. When all the officers had gone ashore, he seized control of the ship, put on a Confederate officer’s hat to hide his black face and sailed past the unsuspecting Confederate canons of Fort Sumter in Charleston harbor. Upon reaching the Union Navy off the coast of South Carolina, he turned over the ship to them. He later was made a captain in the Union navy and given command of the ship until the end of the war. So, are you so sure you were correct when you said, “There were no black heroes during that war”?

■ 25. (a) Identify the conclusion of this argument. (b) Assuming the premises are true, is the argument strong or weak?

No, table tennis could not have been invented before the American Revolution. This is because table tennis needs plastic balls, but plastic wasn’t invented by 1775 when the Revolution began.

■ 26. Identify the conclusion indicator term, if there is any, in the following argument:

According to the New Encyclopedia of the People of Russia, King Ferdinand and Queen Isabella united Aragon and Castille into the modern country of Spain in 1469. They founded the Spanish Inquisition in 1478 as a branch of the government and appointed Torquemada to be the grand inquisitor. This government agency caused all sorts of official terror, and was generally bad for Europeans, although it brought certain short-term benefits to the Catholic Church. On the other hand, King Ferdinand and especially Queen Isabella paid for Christopher Columbus’ trip west to find Asia, and this was very beneficial for the European world because it opened up new sources of wealth, adventure, and knowledge, although there may have been some negatives for the local tribes in the New World. So, Ferdinand and Isabella’s marriage had both good and bad consequences for Europe. Nevertheless, when you weigh the pros and cons, you’ve got to admit that the good heavily outweighs the bad─for Europeans.

a. according to
b. nevertheless
c. on the other hand
d. so
e. There is no conclusion indicator

27. The sentence “I now pronounce you man and wife,” when said by an American judge (justice of the peace) to a couple who have applied for a license to be married, is

a. a claim but not an argument
b. an argument
c. none of the above

28. He’s so good at chess he doesn’t even refer to that piece as the horse.

Argument for the conclusion that he doesn’t even refer to that piece as the horse.

Argument for the conclusion that he’s good at chess.

A claim.

Neither an argument nor a claim.

29. Identify the conclusion indicator and the conclusion in this argument:

Slavery in Saudi Arabia was officially abolished in 1962. That means that if they still have slaves it’s under the legal “radar.”

a. The indicator is “That means” and the conclusion is that slavery in Saudi Arabia is under the legal “radar.”
b. The indicator is “That means” and the conclusion is that slavery in Saudi Arabia was officially abolished in 1962.
c. There is no conclusion indicator, but the conclusion is that if Saudi Arabia still has slaves, then it is under the legal “radar.”
d. The indicator is “That means that if” and the conclusion is that Saudi Arabia still has slaves, and this is under the legal “radar.”
e. None of the above.

30. Describe the following numbered passages by placing the appropriate letter to the left of each number.

a. Merely a claim or statement with no reasons given to back it up.
b. An argument using bad reasons.
c. An argument using good reasons (assuming that the arguer is being truthful).
d. None of the above.

1. You said that all deliveries from your firm would be made on Mondays or Tuesdays and that you would be making a delivery here one day this week. Since it is Tuesday morning and we've had no deliveries this week, your firm should make a delivery today.
2. That night, over icy roads and through howling winds, Paul Revere rode the 60 miles, and even before the British got into their transports, word had come back to Boston that the King's fort at Portsmouth had been seized and His Majesty's military stores stolen by the rebellious Americans.
3. Will you or won't you take me and Johnny Tremain across the Charles River?
4. Not a word to the old gentleman, now; not a word.

31. Arguments in newspaper editorials, unlike ordinary arguments, are usually presented in standard form.

a. true
b. false

Conditionals

1. Does the following sentence express a conditional statement?

An ostrich is a bird; some birds can fly; but an ostrich cannot.

a. yes
b. no
c. can't tell

■ 2. Is the following conditional true?

If kids who are abused usually become abusive parents when they have children, and John Drew is being abused by his mother, then when he grows up he is likely to abuse his own children.

a. yes
b. no
c. need more information to tell

3. If the if-part of a conditional claim is true, and if the conditional claim itself is true, will the then-part have to be true?

4. Is the following statement an argument?

If you had struck this match when it was dry, even though it's now wet, then it would have burst into flame.

Implicit Elements of Arguments

1. If there is an argument present, then there will always be a premise present, even if some of the premises are not present because they are implicit.

a. true
b. false

2. According to this textbook, if a premise or a conclusion is implicit, then it is:

1. very probably true.
2. always uncertain.
3. unstated.
4. none of the above.

■ 3. Identify the implicit conclusion of the following argument, then indicate whether the argument is inductive or deductive.

AIDS will kill everybody who gets it, and your mother has gotten AIDS so you can draw your own conclusion.

4. What is the conclusion of this argument by analogy?

To say that TEX, the scientific word processor language, takes a little effort to learn is like saying that with a little effort you could build your own full-scale, working Challenger spacecraft and run your own space shuttle program. Surely you don't believe you can do this, do you?

5. Rewrite this argument in standard form so that it is deductively valid: "Joshua, quit that! Justine isn't bothering you!" There is at least one implicit premise.

6. When the senator says, "Murder is wrong," and the reporter says, "Well, then you must think capital punishment is wrong, too," the reporter is making an argument, but she is leaving a lot unsaid. Her most significant implicit premise is that the senator thinks

a. Murder is a kind of capital punishment.
b. Capital punishment is a kind of murder.
c. Capital punishment is neither right nor wrong.
d. If capital punishment is wrong, then murder is wrong.

7. Identify the principal implicit element (and say whether it is a premise or a conclusion) in the following argument regarding the correctness of the theory of biological evolution.

According to the fossil record as it is interpreted by evolutionists, spiders have been on earth for 300 million years but have not changed. Yet, if evolution were really working, surely they would have changed by now, wouldn't they?

8. Identify the most significant implicit premise used in the following argument:

All good Americans hate cancer and love the first lady. So, Roberto Salazar Rodriguez loves the first lady.

■ 9. Give the standard form of this deductively valid argument, adding the significant implicit premises, if there are any:

If the moral thing to do is always whatever your society says, then Nazi brutality was morally OK in Nazi Germany. Therefore, the moral thing to do is not always whatever your society says it is.

10. What premise is probably being assumed to make the following argument be deductively valid?

Tom New is running for state treasurer of Indiana, so he knows a lot about public finances.

a. If a person knows a lot about public finances, then the person is running for state treasurer of Indiana.
b. If a person is running for some public office, then the person probably knows a lot about public finances.
c. Tom New is a candidate with financial savvy.
d. Anybody who runs for state treasurer of Indiana is financially ambitious.
e. All candidates for federal office know a lot about public finances.
f. If a person is running for state treasurer of any state, then the person knows a lot about public finances.
g. People who know a lot about public finances often run for state treasurer in Indiana.

■ 11. The following statement is not an argument, but the reader most probably can assume that the speaker believes what?

Stick your hands up or I'll blow your head off.

a. The hands of the person being spoken to are not up.
b. If you stick your hands up, I will blow your head off.
c. The two people have guns.
d. If I blow your head off, then your hands were up.
e. I will blow your head off.

12. Rewrite the conclusion of this argument as a declarative sentence.

What do you mean "We should let a pregnant woman decide whether she has an abortion"? If you let them decide, then you are letting people commit murder. You can't let them do that, can vou?

Multiple Arguments

1. What is the most significant implicit premise used in the first sub-argument of this argument chain?

She's got the flu again, so she probably won't be here to chair the meeting. Therefore, I'll have to do it. Damn!

■ 2. Write out the standard form of the first sub-argument in the following argument.

Galileo said good science uses mathematics, yet Charles Darwin's work on evolution uses no mathematics. Therefore, Darwin's work on evolution is not good science.

3. In the following passage, (a) does Alice argue? If so, what is her conclusion? (b) Does her employer argue? If so, what is his conclusion?

“Maybe. Maybe not,” Alice said as her eyebrows bulged. “But that’s beside the point. He should not be allowed anywhere near that project. Keep him out of there. Get somebody else,” she said. Her employer had other ideas, evidently. He responded, “Listen Alice, you might be in charge of that project, but you’re wrong, dead wrong. Think about it.” “Look,” said Alice, biting through her words, “there is no way in hell that I’m going to permit him to do that, and if you don’t like it, you know what you can do with it.” After several days, things quieted down between the two of them, but last week Alice received her termination notice. That was the day she bought the poison.

a. Alice is arguing that he should not be allowed anywhere near that project.
b. Her employer is arguing that she bought the poison.
c. Her employer is arguing that he should be permitted to work on the project.
d. Nobody is giving anybody reasons.

■ 4. In this complex argument, one of the statements is an intermediate conclusion rather than the final conclusion. Identify it.

You should do well, since you have talent and you are a hard worker. I know you have talent, even though you don’t believe it, because I’ve seen you perform and you’re better than most people I’ve seen do this. Besides, Lady Gaga and Beyoncé both say you’re talented.

a. You should do well.
b. You have talent.
c. You are a hard worker.
d. I’ve seen you perform and you’re better than most people I’ve seen do this.
e. Lady Gaga and Beyoncé both say you’re talented.

■ 5. Consider the following complex expressions which are composed of simple claims. The simple claims are abbreviated as A and B and C. For each of the complex expressions, say whether it is an argument or merely a claim:

a. A, but not B.
b. A, but not B, and consequently C.
c. A, which is why B, but not C.
d. A and B follow from C.
e. A and maybe B, or perhaps C.

Creating and Improving Arguments

1. Research the issue of whether the United States can afford to expand its space program. Take a side and create a 200- to 300-word argument in defense of your position. Give credit to your sources (that is, use footnotes to say where your information came from).

■ 2. Lesley and Rico say they’ve found a deductively valid, simple argument that, when rewritten in standard form, is a mixture of true and false sentences in which the premises are all true. Why is this unusual?

3. The following passage is an argument. Construct a new argument that defends the opposite conclusion but that devotes about half its attention to countering the points made in the first argument.

America should have more alcoholics. Here is why. Drinking alcohol makes you feel good, and Americans deserve to feel good, if anybody does. Legislators who are alcoholics will be off playing golf or hanging out in bars; they will be preoccupied and therefore won't pass so much harmful legislation that rips off us taxpayers. Besides, if I want to be an alcoholic and don't do anything to harm you, then you shouldn't be telling me what I can do with my body; it's my body, not your body, right?

You will be graded on the clarity of your argument, your ability to foresee counters from your opponents, and the absence of silly, naive, or irrelevant comments. The upper limit on your new argument should be two pages, typed double-spaced.

4. Construct an argument defending your position on the issue of whether there ought to be a law permitting the county public health department to start a needle exchange program. Under this program, drug addicts would be given new or clean hypodermic needles in exchange for their old or used needles, no questions asked. The purpose of the program would be to slow the spread of AIDS in the county.

Background: Assume that it is a misdemeanor to possess a hypodermic needle that has not been prescribed by a doctor and that it is a misdemeanor for a doctor to prescribe or give away hypodermic needles and other drug addiction paraphernalia except for certain listed problems, such as diabetes and allergies.

You will be graded not on what position you take but on the clarity of your argument, your ability to foresee counters from your opponents, and the absence of silly, naive, or irrelevant comments. Keep your argument to two pages, typed, double-spaced.

5. This is an exercise to be done by four students working as a group. The group chooses an issue to debate in front of the rest of the class, but the issue must be approved by the instructor. The group meets outside of class to research the issue. A typical issue might be whether the college should spend more money on athletic scholarships and less money on other projects. Another issue might be whether U.S. defense spending should be cut. Two students agree to argue for a yes position on the issue; the other two students agree to argue for the no position. During the class debate, all four students speak alternatively, each for five minutes or less. Speakers may use their time either to present arguments for their own position or to attack arguments presented by the opposition. When the four are done, the rest of the students in the class get to ask them questions or otherwise enter into the debate. The goal of the exercise is to show a significant understanding of the issue and to carry out good logical reasoning on the issue. Depending on your instructor, students who are not in the group of four may be required to summarize and discuss the quality of the reasoning of the group.

Descriptions, Explanations, and Arguments

1. Are the following three passages most probably expressing arguments, explanations, descriptions, or what?

a. A quartz crystal oscillator is very small and contains a crystal of the mineral silicon dioxide that can be made to vibrate when stimulated electrically.
b. A clock's quartz crystal oscillator is a fascinating device that is not as complicated as it may seem to be. Here is how it works. Power from a small battery makes the crystal vibrate, and when this happens the crystal gives out pulses of current at a very precise rate, a fixed electrical frequency. A microchip reduces this rate to one pulse per second, and this signal activates the time display mechanism for the second hand.
c. Many clocks and watches contain a quartz crystal oscillator that controls the hands or the time display. Power from a small battery makes the crystal vibrate, and it gives out pulses of current at a very precise rate—that is, a definite frequency. A microchip reduces this rate to one pulse per second, and this signal activates the time display mechanism.

2. Suppose you asked someone to explain why tigers eat meat but not plants, and you got the answer, "Because a zookeeper once told me that's what they eat." You should consider this to be an incorrect answer. Why?

a. You asked for some sort of explanation of why tigers eat meat but not plants, yet the answer mentioned nothing about plants.
b. You requested an explanation but got an argument instead.
c. Zookeepers usually have no idea what tigers eat.
d. Nobody thought to mention that meat is not made out of plants.

3. Suppose you have asked your English instructor why Ernest Hemingway won the 1954 Nobel Prize for literature, and suppose she answers, "He won because the Swedish Nobel Committee liked his short stories and novels about his own experiences in World War I and in the Spanish Civil War of the late 1930s." She is

a. explaining but not arguing.
b. explaining and arguing.
c. only describing.
d. describing and arguing.
e. only arguing.

4. When Betsy says "I'm angry," she is reporting information about her state of mind, not arguing for a conclusion. But is she explaining or not explaining here state of mind?

5. The following passage is primarily

a. a description
b. an argument
c. a request

About two-thirds of the salt in seawater is sodium chloride. Other substances present are magnesium chloride, sodium sulfate, potassium chloride, and calcium chloride. In the remaining one percent of salts are tiny traces of about forty different elements, including iron, uranium, silver, and gold. The percentage of gold is so small that you would have to process tons of seawater to get even a tiny amount. If the salt were taken out of all the seawater in the world and distributed across the land, it could cover all the land areas on Earth with a layer 500 feet thick.

6. The following passage is primarily

a. a description
b. an argument
c. a request

The sun's rays do not fall vertically outside the tropics, even at noontime. June 21 in the northern hemisphere is the day of the year with the longest daytime. On this day, the perfectly vertical fall of the sun's rays is farther north than on any other day of the year. This special, farthest north place is actually a line of places around the earth at 23.5° north latitude. It is called the Tropic of Cancer. The day when the sun reaches the Tropic of Cancer is called the solstice, and it begins the summer. Hawaii is the only part of the U.S. that is south of the Tropic of Cancer.

7. Is this passage primarily an argument or an explanation?

Figure \(\PageIndex{1}\)

Mayfield is guilty because the FBI report says that his fingerprints match those on the countertop beside the cash register.

8. Is this passage primarily an argument or an explanation?

The passenger died because the driver was drunk and speeding on the freeway.

9. Take a least two of the following sentences and work them into an argument on the issue of which computer your office should purchase.

a. The Apple clone is cheaper than the Cray-Sinclair, although both are within our budget.
b. The Cray-Sinclair computer is faster than the Apple clone.
c. The Cray-Sinclair won't run Word, and the Apple clone runs all the software we want right now.
d. The Cray-Sinclair has a better service contract than the Apple clone.

Evaluating Arguments

Although much of the rest of this book is devoted to the topic of evaluating arguments, here are some initial exercises.

1. How good is this argument? Is it inductively strong? Is it valid?

Anytime you murder someone you are killing that person.

So, if a pilot kills someone during the battle, the pilot is murdering that person during the battle.

■ 2. How good is this argument? Is it inductively strong? Is it valid?

Anytime you murder someone you are killing that person.

So, if a pilot murders a person during the battle, then the pilot kills someone during the battle.

3. Evaluate the quality of this argument:

Nathan was arrested for breaking and entering. At the trial two witness who didn’t know each other or know Nathan testified that Nathan committed the crime. The defense attorney said Nathan was 10 miles away at the time, but the only evidence for this was Nathan’s own claim that he was 10 miles away at the time.

4. Evaluate the quality of this argument:

All ice eventually melts when heated to over 47 degrees Fahrenheit. The ice in the refrigerator of the President of France was heated to over 47 degrees Fahrenheit that day. So, the ice in the President’s refrigerator eventually melted.

■ 5. Does this argument have any counterexamples? If so, find one.

All cats are interesting animals.
All cats have fur.
So, all interesting animals have fur.

6. Does this argument have any counterexamples? If so, find one.

All cats are interesting animals.
All interesting animals have fur.
So, all cats have fur.

■ 7. Does this argument have any counterexamples?

Either Juan is coming to the party and bringing the beer or Tom is staying home and watching his favorite program. Juan is definitely coming to the party. Therefore, Juan is bringing the beer.

8. Discuss the following argument. At the very least, describe it and evaluate it. Are some reasons better than others?

Drinking alcohol causes kidney disease, traffic accidents, and other serious problems. In addition, the singer Michael Jackson says drinking is an undesirable habit. Your older brother says no one will kiss a person whose breath smells like alcohol. Therefore, no sensible, intelligent person should ever drink.

Solutions

Detecting Single, Explicit Arguments
1. Answer (c)
2. Answer (c)
3. Answer (a), assuming you are going to take this question seriously, but the jokes in c and d might be a reason to doubt this assumption. Usually declarative sentences are used to make claims, but not always. The declarative sentence “I promised to meet you” is true or false, but the declarative sentence “I promise to meet to” is neither.
5. Answer (a). This is probably an explanation. It is explaining why dynamic random access memory (DRAM) chips were once the popular choice for memory storage on personal computers.
6. Answer (c). It is just a description
8. Suppose that.
9.Thus.
10. Yes, the word since is used twice as a premise indicator
15. Yes, it is a making two statements, that America is a land of catastrophic wealth imbalance and that America’s flag should continue to wave. The second statement is probably meant sarcastically.
16. Answer (d). To get this answer you had to remember that premise order is irrelevant.
17. Not an argument. Could it be interpreted as an argument for the conclusion that Snow White is the fairest of them all? Couldn't the reasons for this conclusion be that the mirror said so? No, what is happening in the passage is not an argument trying to convince the reader or the queen of this conclusion. Instead, the queen asked a question about who is the fairest, and the mirror answered that it is Snow White and proceeded to describe Snow White. The passage is a narrative, a story. The passage does give sufficient information to draw the conclusion that Snow White is the fairest for the reason that the mirror said so, yet the reader is not expected to do this kind of reasoning. The reader can tell from the rest of the passage that the writer's intent is merely to provide the information that Snow White is fairest and then to elaborate on the point by providing the information about the mirror.
21. No argument. The passage is giving you advice, not reasons for the advice. You could imagine someone creating an argument from this. It might be that the advice should be taken because it will lead you to safety in this situation, and you ought to accept advice that will do this.
22. The discount indicator is “I realize that … but” and the discount claim is “We did promise to give the knife back soon.”
25. (a) Table tennis could not have been invented before the American Revolution. (b) Strong. This is a good argument.
26. Answer (d)
28. Answer (c)

Conditionals
2. Yes. Then then-part follows from the if-part

Implicit Elements of Arguments
1. Answer (a). If all the premises were left unstated, there would be no arguing and instead merely the making of a claim.
3. Conclusion: Your mother, too, will be killed by AIDS. The argument is deductive; and it is deductively valid.
9. Here is the standard form:
If the moral thing to do is always whatever your society says, then Nazi brutality was ethically OK in Nazi Germany. Nazi brutality was not morally OK in Nazi Germany.
----------------------------------------------------------------------------------------
The moral thing to do is not always whatever your society says it is.
11. Answer (a)

Multiple Arguments
2. The sub-argument in standard form is:
Galileo said good science uses mathematics.
--------------------------------------------------------------
Good science uses mathematics.
4. Answer (b). Here is the main argument:
You have talent.
You are a hard worker.
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You should do well. Its first premise is not basic because it is argued for. Here is that argument:
I’ve seen you perform and you’re better than most people I’ve seen do this. Lady Gaga and Beyoncé both say you’re talented.
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You have talent.
5. (a) claim, (b) argument. Try to work (c) and (d) and (e) on your own

Creating and Improving Arguments
2. In a valid argument with true premises, the conclusion has to be true, too. So, there couldn’t be any false statements. What Lesley and Rico are saying is contradictory

Descriptions, Explanations, and Arguments
1.
a. Description of a quartz crystal oscillator. Not an explanation.
b. This is an explanation of how a quartz crystal oscillator works in a clock. The passage also provides some additional description of the inside of a clock that uses the oscillator.
c. Like passage (b), this one describes the inner workings of a certain kind of clock. Compared to (b), it is harder to tell whether any explanation is present, but probably one is present. To tell whether an explanation is present, the reader must look at what is said, then try to reconstruct the intentions in the mind of the speaker. If the intentions were to say (1) what causes what, (2) what motivates an action, (3) what purpose something has, or (4) what origin something has, then an explanation is present. Otherwise, there is only description.
3. Betsy Ross is describing, but she might or might not be explaining, depending on the context. If she just makes this statement out of the blue, she is not offering a cause for some event, nor offering a motivation for what happened. She is simply describing the state of her body or mind. However, if the context were that she has just been asked to explain why she ripped her new flag to pieces, her response would count as an explanation of this action.
5. Answer (a). The passage is describing the constituents of sea water; it is not giving reasons for some conclusion nor requesting anything of the reader

Evaluating Arguments
2. This is a very strong argument. It is deductively valid and all its premises (there’s just one) are true.
4. The argument meets the standard of being deductively valid. But you’ll have to suspend judgment about whether the argument is a good reason to believe the conclusion because you don’t know whether one of its premises is true. You don’t know whether it is true that the ice in the refrigerator of the President of France was heated to over 47 degrees Fahrenheit that day.
5. The following situation is a counterexample: a situation where all cats and crocodiles are interesting animals and all cats have fur but crocodiles don’t. In this situation the premises are both true but the conclusion is false, so we have a counterexample that shows the argument was deductively invalid.
7. You can imagine a situation where Juan comes to the party without the beer, while Tom says home and watches his favorite program. In that situation the premises are true while the conclusion is false. So this is a counterexample, and the argument is deductively invalid.