4 CHAPTER 1 Critical Thinking?
Example 2 Your teacher is short.
Analysis Is this a claim? Probably not, since the word "short" is so vague. We'll
consider problems with vagueness in Chapter 2.
Example 3 Cats are nasty.
Analysis If when you read this you disagreed, then you are implicitly accepting the
example as a claim. You can't disagree unless you think it has a truth-value.
Example 4 2 + 2 = 4
Analysis This is a claim, though no one is going to disagree with you about it.
Example 5 I wish I could get a job.
Analysis How is this being used? If Maria, who's been trying to get a job for three
weeks, says it to herself late at night, then it's not a claim. It's more like a prayer or
an extended sigh.
But if Dick's parents are berating him for not getting a job, he might say, "It's
not that I'm not trying. I wish I could get a job." That might be true, but it also
might be false, so in this context "I wish I could get a job" would be a claim.
Example 6 How can anyone be so dumb as to think that computers can think?
Analysis As it stands this is not a claim; it is a question. But in some contexts we
might rewrite it as "Someone must be dumb to think that computers can think," or
perhaps "Computers can't think." The process of rewriting and reinterpreting is
something we'll consider throughout this course.
Example 7 Todo cachorro pode latir.
Analysis Is this a claim? If you don't understand Portuguese, you better say you're
not prepared to accept it as one. You can't reason with it if you don't understand it.
Example 8 Every mollusk can contract myxomatosis.
Analysis If you don't know what these words mean, you shouldn't try to reason
with this as a claim. But that doesn't mean you should just dismiss any attempt to
convince that uses language you don't understand. A dictionary is an important tool
of a good reasoner.
C. Arguments
We're trying to define "argument." We said it was an attempt to convince someone,
using language, that a claim is true. The only language that we should allow in an
argument, then, should be sentences that are true or false.
SECTION C Arguments 5
Argument An argument is an attempt to convince someone
(possibly yourself) that a particular claim, called the conclusion, is true.
The rest of the argument is a collection of claims called premises,
which are given as the reasons for believing the conclusion is true.
The point of an argument is to convince that a claim—the conclusion—is true.
The conclusion is sometimes called the issue that's being debated.
Critical thinking is evaluating whether we should be convinced that some
claim is true or some argument is good, as well as formulating good arguments.
E x a m p l e s Are the following arguments?
Example 1
Analysis The nurse is making an argument. She's trying to convince the doctor
that "Your patient in Room 47 is dying" is true. She offers the premise: "He's in
cardiac arrest." Sounds pretty convincing.
Example 2
Analysis Dick is making an argument, trying to convince the police officer that the
following claim is true: "The accident was not my fault" (reworded a bit). He uses
two premises: "She hit me from the rear" and "Anytime you get rear-ended it's not
your fault."
6 CHAPTER 1 Critical Thinking?
Example 3 Out? Out? I was safe by a mile. Are you blind? He didn't even touch
me with his glove!
Analysis This was spoken at a baseball game by a runner who'd just been called
out. He was trying to convince the umpire to believe "I was safe." He used only one
premise: "He didn't even touch me with his glove." The rest is just noise.
Example 4 Give me that fucking wrench.
Analysis I can remember who said this to me. He was trying to convince me. But
it was no argument, just a series of commands and threats. And what he was trying
to convince me of wasn't the truth of some claim.
Example 5 Follow the directions provided by your doctor for using this medicine.
This medicine may be taken on an empty stomach or with food. Store this medicine
at room temperature, away from heat and light.
Analysis This is not an argument. Instructions, explanations, and descriptions,
though they may use declarative sentences, aren't arguments. They're not intended
Example 6
Analysis Zoe's mother is attempting to convince her, but not of the truth of a claim.
So there's no argument. Perhaps we could interpret what is being said as having an
unstated conclusion "You should feel guilty for not calling your mother," and
premises (disguised as questions) "Anyone who doesn't call her mother doesn't love
her mother" and "If you don't love your mother, then your mother did something
wrong." But it would be the interpretation that is an argument, not the original. And
we would have to consider whether the interpretation is faithful to what Zoe's
mother intended. We'll consider the process of interpretation in Chapter 4.
Example 7 The sky is blue. That's because sunlight is refracted through the air in
such a way that other wavelengths of light are diminished.
Analysis This is not an attempt to convince you that the sky is blue—that's
obvious. This is an explanation, and an explanation is not an argument.
Example 8 You see a chimpanzee trying to get some termites out of a hole. She
can't manage it because the hole is too small for her finger. So she gets a stick and
tries to pull the termites out. No success. She licks the end of the stick and puts it in
EXERCISES for Chapter 1 7
the hole and pulls it out with a termite stuck to it. She eats the termite, and repeats
the process. Is she convincing herself by means of an argument?
Analysis This isn't an argument. Whatever the chimpanzee is doing, she's not
using claims to convince herself that a particular claim is true.
But isn't she reasoning? That's a hard question you can study in philosophy
and psychology courses.
Summary We said that this course will be about attempts to convince. But that's too
much for one course. We narrowed the topic to attempts to convince that use
language. That was still too broad. An argument, we decided, should mean an
attempt to convince someone that a sentence is true. We defined a claim as a
declarative sentence used in such a way that it is true or false. Arguments, then,
are attempts to convince that use only claims.
Now we'll begin to look at methods and make distinctions. Because your
reasoning can be sharpened, you can understand more, you can avoid being duped.
And, we can hope, you will reason well with those you love and work with and need
to convince, and you will make better decisions. But whether you will do so depends
not just on method, not just on the tools of reasoning, but on your goals, your ends.
And that depends on virtue.
Key Words truth-value claim premise
true argument issue
false conclusion critical thinking
Exercises for Chapter 1
These exercises are meant to help you become familiar with the basic ideas we've seen in
this chapter. They should raise enough worries about the nature of claims and arguments
that you'll be glad to see how we clarify those in the next few chapters.
1. What is this course about?
2. How did I try to convince you that this course is important? Pick out at least two places
where I tried to convince you and decide whether they are arguments.
3. Explain how to divide up all attempts to convince in terms of who is trying to
convince whom.
4. Which of the following are claims?
a. Keanu Reeves is a woman.
b. I am 2 meters tall.
c. Is any teacher capable of writing a good exam?
d. Power corrupts.
8 CHAPTER 1 Critical Thinking?
e. Feed Spot.
f. Did you feed Spot?
g. A friend in need is a friend indeed,
h. No se puede vivir sin amor.
i. Whenever Spot barks, Zoe gets mad.
j. Britney Spears wasn't married in Las Vegas.
k. Your instructor believes that Britney Spears wasn't married in Las Vegas.
1. 2 + 2 = 5
m. I feel cold today.
n. There is an odd number of stars in the universe.
5. Write down five sentences, four of which are claims and one of which is not.
Exchange with a classmate and see if he or she can spot which are the claims.
6. What is an argument?
7. What is the point of making an argument?
8. What is a premise? What is a conclusion?
9. Why isn't every attempt to convince an argument? Give an example.
10. Bring in an example of an argument you heard or read in the last two days.
11. Bring in a short article from the front page of a newspaper. Are all the sentences used in
it claims? Is it an argument?
12. Your friend goes outside, looks up at the sky, and sees it's cloudy. She goes back inside
and gets her raincoat and umbrella. Is she making an argument? Explain.
13. Bring an advertisement to class that uses an argument. State the premises and the
conclusion.
Here are two exercises done by Tom, along with Dr. E's comments.
Tom Wyzyczy
Critical Thinking
Section 4
Sheep are the dumbest animals. If the one in front walks off a cliff, all the
rest will follow it. And if they get rolled over on their backs, they can't right
themselves.
Argumentl (yes/no) Yes.
Conclusion: Sheep are the dumbest animals.
Premises: If a sheep walks off a cliff, all the rest will follow it.
If a sheep gets rolled over on its back, it can't right itself.
This is good work, Tom.
EXERCISES for Chapter 1 9
How can you go to the movies with Sarah and not me? Don't you remember I
helped you fix your car last week?
Argument! (yes/no) Yes.
Conclusion: You should go to the movies with me.
Premises: I helped you fix your car last week.
Is what you are given an argument? No. There are just two questions, and
questions aren't claims. So it can't be an argument. And if there's no
argument, there are no-premises and no conclusion. Sure, it seems that we
ought to interpret what's said as an argument— as you have done. 'But before
we go putting words in someone's mouth, we ought to have rules and a better
understanding of when that's justified.
Answer each of Exercises 14-26 in the same way: State whether it is an argument. If it is
an argument, identify the premises and conclusion.
14. You shouldn't eat at Zee-Zee Frap's restaurant. I heard they did really badly on their
health inspection last week.
15. You liked that movie? Boy, are you dumb. I guess you just can't distinguish bad acting
from good. And the photography was lousy. What a stupid ending, too.
16. If it's O.K. to buy white mice to feed a pet boa constrictor, why isn't it O.K. to buy
white mice for your cat to play with?
17. If you don't take a course on critical thinking, you'll always end up being conned, a dupe
for any fast-talker, an easy mark for politicians. So you should take a course on critical
thinking. You'd be especially wise to take one from the instructor you've got now—
he [she] is a great teacher.
18. Whatever you do, you should drop the critical thinking course from the instructor you've
got now. He [she] is a really tough grader, much more demanding than the other
professors that teach that course. You could end up getting a bad grade.
19. I would not live forever, because we should not live forever, because if we were
supposed to live forever, then we would live forever, but we cannot live forever, which
is why I would not live forever.
(A contestant's response to the question "If you could live forever, would you
and why?" in the 1994 Miss USA contest.)
20. (Advertisement) The bigger the burgers, the better the burgers, the burgers are bigger at
Burger King.
21. Look Dick! Look Zoe! See Spot. See Spot run.
22. Flo has always wanted a dog, but she's never been very responsible. She had a fish
once, but it died after a week. She forgot to water her mother's plants, and they died.
She stepped on a neighbor's turtle and killed it.
10 CHAPTER 1 Critical Thinking?
23. Maria: Ah-choo.
Lee: Gesundheit.
Maria: I'm just miserable. Stuffy head and trouble breathing.
Lee: Sounds like the allergies I get.
Maria: No, it's the flu. I'm running a fever.
24. You may own stocks or securities which are selling at a lower price than when
purchased. Tax considerations might call for a sale of such securities in order to create
a currently deductible tax loss. However, if it is desired to still own the securities while
producing a tax loss, you can't just sell securities at a loss and then buy them right back.
Any purchase of the same securities within 30 days before or after the sale negates any
losses. To get around this restriction, you can purchase similar but not identical
securities to the ones sold. Or, in the case of bonds, you can achieve the same result by
making a swap through a brokerage house.
1994 Tax Guide for College Teachers
25. The light bulb is located in the upper left corner of the oven. Before replacing the bulb,
disconnect electric power to the range at the main fuse or circuit breaker panel or unplug
the range from the electric outlet. Let the bulb cool completely before removing it. Do
not touch a hot bulb with a damp cloth as the bulb will break.
To remove: Hold hand under lamp bulb cover so it doesn't fall when released. With
fingers of same hand, firmly push down wire bail until it clears cover. Lift off cover.
Do not remove any screws to remove this cover. Replace bulb with a 40-watt home
appliance bulb.
How to get the best from your range, Hotpoint
26. Letter to the editor:
I'm 45, a mother and a postal worker. I also happen to be in a long-term relationship
with a woman. We both work, pay taxes, vote, do volunteer work, and lead full,
productive lives.
My partner Sara and I have been together for over four years and we formalized our
lifetime commitment to each other in a ceremony several years ago. In a fair and non-
discriminating society, we would be able to obtain the same benefits for e
ach other that
heterosexual Americans obtain when they marry.
I've worked for the postal service for 10 years, yet I can't obtain health insurance for
Sara, nor can I use family leave to care for or be with her if she's ill, has had surgery or
has been injured.
Heterosexual employees who are married or get married can get benefits for a
spouse and any number of children, including adopted, foster and stepchildren.
Even when we have legal papers drawn up to protect our rights, property and
relationships, it often takes lengthy and expensive court battles to get other people to
honor our wishes and instructions. Sometimes we lose those battles, and some rights
(like family health insurance coverage) we simply can't get.
No one should be surprised that we want the right to marry.
Kathy Worthington, The Spectrum, May 26, 1996
27. In order to choose good courses of action in our lives, we need not only knowledge of
the world and the ability to reason well, but what else?
EXERCISES for Chapter 1 11
Further Study There is much more to learn about the nature of claims, truth, falsity,
and the relation of language to our experience. We'll touch on some of those in the
next chapter. An introductory philosophy course goes much deeper.
Attempts to convince that use language but aren't arguments, such as fables
and examples, are studied in courses in rhetoric. Courses in marketing, advertising,
or psychology study both verbal and nonverbal ways to convince that aren't
arguments. Convincing that uses body language is at the heart of acting classes.
A place to begin reading about whether animals can reason is The Animal
Mind, by James and Carol Gould, Scientific American Library.
Writing Lesson 1
Write an argument either for or against the following:
Student athletes should be given special leniency when the instructor
assigns course marks.
Your argument should be at most one page long.
12
2
What Are We
Arguing About?
A. Vague Sentences
1. Too vague? 13
2. Ambiguous sentences 16
• Exercises for Section A 17
B. Subjective and Objective Claims 19
• Exercises for Section B 23
C. Prescriptive Claims and Value Judgments 24
• Exercises for Section C 25