Critical Thinking An Appeal to Reason Peg Tittle

287 Pages·2011·4.69 MB·English

STUDENT MANUAL TO ACCOMPANY
Critical
Thinking
An Appeal to Reason
Peg Tittle
s
t
n
e
t
n
o
c
s
t
critical thinking
n
answers,
explanations
e
and analyses
t
Answers, Explanations, and Analyses are for odd numbered
questions in the book.
n Note that all terms in the end-of-chapter “Review of terms”
can be found in the Glossary.
CHAPTER 1 5
CHAPTER 2 8
CHAPTER 3 39
o CHAPTER 4 60
CHAPTER 5 96
CHAPTER 6 119
CHAPTER 7 146
CHAPTER 8 172
CATEGORICAL LOGIC 201
c
PROPOSITIONAL LOGIC 232
THINKING CRITICALLY ABOUT ETHICAL ISSUES 271

Chapter 1
Critical
Thinking
Thinking critically about what you see
© Corbis
1. You might start by articulating the implications of the photograph: given its clear and
simple focus on the smiling little girls, it seems to be endorsing (female) child beauty
pageants. Do you agree with that endorsement? Is it okay to encourage little girls to—
what? To pay excessive attention to their appearance? To look like adults?
5
A N S W E R S , E X P L A N A T I O N S , A N D A N A L Y S E S ( O D D N U M B E R E D )
Thinking critically about what you read
There’s nothing wrong with downloading music from the internet. First, everyone does
it, and second, it’s not like you’re taking something—after you download, the song’s
still there, it’s not like taking someone’s car. Some people say downloading music from
the internet isn’t fair because the musicians don’t get paid when you download, but
you’re paying for the internet connection—why should you have to pay twice? That’s
not fair! And people say that if everyone does it, sales of CDs will decrease, and then
since there’ll be no money in making CDs, the recording companies will stop making
them. But everyone’s not doing it, so CD sales won’t decrease. And actually, a friend
of mind told me that after their band put one of their songs on their website, sales of
their CD increased! Lastly, downloading is legal; anything that’s morally acceptable is
legal; so downloading must be morally acceptable. People should stop worrying about
this stuff and go after the realcriminals!
You might consider the consequences a little more thoroughly (though this speaker does
a pretty good job of it!)...not just to the musicians, but also to big business and to society-
in-general (if we don’t download, will our lives, our society, become music-poor?)...Intent
could also be considered (this passage doesn’t seem to get into intent)...when you
download, are you trying to get something for nothing?
The issues of justice and fairness could be thought about a bit more: what exactly
is fair in this context? Who deserves what? On what basis? (Who owns what? And so
what—what rights does ownership entail? Is ownership the best way of approaching the
issue?)
The relationship between legality and morality could also use a bit more scrutiny …
just because it’s legal, does that mean it’s moral? It’s legal to break a promise, but is it
morally right?
Who are “the realcriminals” referred to at the end?
You might notice the appeal to the majority (jump ahead to Section 4.3.5).
Lastly, you might consider alternative arrangements or “solutions”—minimal payment,
consent, barter...—that might affect whether or not it’s right to download music...
Reasoning test questions
1. Computers perform actions that are closer to thinking than anything nonhuman
animals do. But computers do not have volitional powers, although some nonhuman
animals do.
Which one of the following is most strongly supported by the information above?
*(A)Having volitional powers need not involve thinking.
6
C R I T I C A L T H I N K I N G
This is the correct answer. Computers are more capable of thinking than nonhuman animals,
but nonhuman animals are capable of volition whereas computers are not, so there doesn’t
seem to be a relation between thinking and volition.
(B) Things that are not animals do not have volitional powers.
The only things-that-are-not-animals mentioned in the passage are computers, and the
passage does say that computers do not have volitional powers, but we can’t generalize
from that one case to allthings-that-are-not-animals.
(C) Computers possess none of the attributes of living things.
The passage states only that computers do not possess volition; it doesn’t follow that they
posses noattributes of living things. In fact, that computers “perform actions that are closer
to thinking than anything nonhuman animals do” suggests that they may possess some
level of cognition (an attribute of living things).
(D) It is necessary to have volitional powers in order to think.
The passage suggests that computers almost think and yet do not have volition, so if
anything, the passage suggests that it is notnecessary to have volitional powers in order to
think.
(E) Computers will never be able to think as human beings do.
There is nothing in the passage to suggest this.
(The Official LSAT Pep Test XXIII,Section 2, #7)
7
Chapter 2
The Nature
of Argument
2.2a Recognizing premises and conclusions
1. It’s puzzling that Taffi(the canine I live with) doesn’t play with toys more often,
given that she has her own toybox. And it’s overflowing. But then, she has me!
Note this argument has twopremises leading to the conclusion: the first premise
is “She has her own toybox” and the second is “It’s overflowing”; together, they
provide support for the conclusion, “It’s puzzling that Taffidoesn’t play with toys
more often.”
The last sentence is not part of the argument; rather, it suggests a second
argument (Taffidoesn’t play with toys becauseshe has me to play with).
3. “We know he’s a real man because he threw a refrigerator across the room
during a fight.”
(Jason Cohen and Michael Krugman, writing tongue-in-cheek
about a popular television show, Generation Ecch!)
There is one premise, “He threw a refrigerator across the room during a fight,”
leading to one conclusion, “He’s a real man.”
5. “The Soviet pledge not to be the first to use nuclear weapons goes to confirm
that the USSR is against any nuclear aggression and that its military doctrine
is, indeed, a defensive one in nature.”
(Information Centre of the World Peace Council,
“Nuclear Weapons: No First Strike, No First Use,” no date)
8
T H E N A T U R E O F A R G U M E N T
Note that there are two conclusions here that are thought to follow from the
premise (see Section 3.5): the premise, the Soviet pledges not to be the first to use
nuclear weapons, is taken to support two conclusions: they are against nuclear
aggression and that their military doctrine is defensive in nature.
However, the second conclusion is, it seems to me, too broad, given the
premise it rests on: what about other kinds of weapons (chemical, biological, and
so on)? Unless the Soviet has pledged not to be the first to use those as well, it
does notfollow that its military doctrine is defensive in nature.
7. Burglars generally avoid the houses known to have guns in them. And people
have a right to defend what’s theirs. Consequently, we should legalize guns;
that way, people can defend themselves against burglars.
You’ll see these are getting a little more difficult. The difficulty in this one is mostly
due to the poor writing/thinking. The argument seems to be that we should
legalize guns (conclusion) because that would enable people to defend themselves
against burglars (premise) and, an implied premise (we’ll get to implied premises
in the next section), people have a right to defend themselves against burglars
(premise).
The first sentence, however, seems to confuse the issue: if burglars avoid
houses known to have guns in them, the people will have no need to defend
themselves. Unless “defend” is intended to mean “deter”...
Also, you might point out the assumption that people are able to defend
themselves with guns. Merely having a gun does not ensure this.
Lastly, you might counter with the observation that burglars tend to avoid
occupied houses, with guns or not—in which case, guns for defense against
burglars would be largely unnecessary.
9. Tuition fees should be lowered, due to the scarcity of jobs. Most students
don’t want to work while they’re going to school anyway. And parents don’t
always give their kids enough money for tuition andall the other stuff they
want. I mean, you can’t expect students to study all the time, they want to
have fun, they want to party, see movies, listen to music. And all of that costs
money.
Notice how unfocused this is. At first reading, the second sentence seems irrelevant
to the argument, which seems to be that tuition fees should be lowered (con-
clusion) because there aren’t enough jobs for students (premise) and parents don’t
give their kids enough money (premise). However, perhaps the first premise is
intended to be “students don’t have jobs” rather than “there aren’t enough jobs
for students”—in which case, there are two premises supporting that premise
(students don’t have jobs because one, there aren’t enough jobs and two, they
don’t want them anyway).
9
A N S W E R S , E X P L A N A T I O N S , A N D A N A L Y S E S ( O D D N U M B E R E D )
2.2b Practice using standard form
1. It’s puzzling that Taffi (the canine I live with) doesn’t play with toys more
often, given that she has her own toybox. And it’s overflowing. But then, she
has me!
1. Taffihas her own toybox.
2. Taffi’s toybox is overflowing.
Therefore, it’s puzzling that Taffidoesn’t play with toys more often.
And the implied second argument would be:
1. Taffi has me to play with.
Therefore, she doesn’t play with toys.
3. “We know he’s a real man because he threw a refrigerator across the room
during a fight.”
(Jason Cohen and Michael Krugman, writing tongue-in-cheek
about a popular television show, Generation Ecch!)
1. He threw a refrigerator across the room during a fight.
Therefore, he’s a real man.
5. “The Soviet pledge not to be the first to use nuclear weapons goes to confirm
that the USSR is against any nuclear aggression and that its military doctrine
is, indeed, a defensive one in nature.”
(Information Centre of the World Peace Council,
“Nuclear Weapons: No First Strike, No First Use,” no date)
1. The Soviet has pledged not to be the first to use nuclear weapons.
Therefore, the USSR is against any nuclear aggression.
and
Therefore, the USSR’s military doctrine is a defensive one in nature.
7. Burglars generally avoid the houses known to have guns in them. And people
have a right to defend what’s theirs. Consequently, we should legalize guns;
that way, people can defend themselves against burglars.
1. Guns enable people to defend themselves against burglars.
2. People have a right to defend themselves against burglars.
Therefore, we should legalize guns.
9. Tuition fees should be lowered, due to the scarcity of jobs. Most students
don’t want to work while they’re going to school anyway. And parents don’t
10