possibilities without specifying any one of them: "Almost all dogs bark." That's the glue that links the premise to the conclusion. Then the argument is good.
Example 4 Dr. E is a good teacher because he gives fair exams.
Analysis The unstated premise needed to make this valid or strong is "Almost any
teacher who gives fair exams is a good teacher." That gives a strong argument. But
it's not plausible: A teacher could copy fair exams from the instructor's manual.
(If you thought the claim that's needed is "Good teachers give fair exams," then
reread Example 2.) The argument can't be repaired because the obvious premise
to add to make the argument strong or valid is false or dubious.
But can't you make it strong by adding, say, "Dr. E gives great explanations,"
"Dr. E is amusing," "Dr. E never misses class," . . . ? Yes, all those are true, and perhaps obvious to the person. But adding those doesn't repair this argument—it
makes a whole new argument. Don't put words in someone's mouth.
Example 5 Dick: Dogs are loyal. Dogs are friendly. Dogs can protect you from
intruders.
Maria: So?
Dick: So dogs make great pets.
Maria: Why does that follow?
Analysis Maria's right. Dick's argument is missing the "glue," the link between
premises and conclusion that rules out other possibilities, in this case, something like
"Anything that is loyal, friendly, and can protect you from intruders is a great pet."
But it's exactly that which Maria thinks is false: Dogs need room to run around, they
need to be walked every day, it costs more to take care of a dog than a goldfish,....
Just stating a lot of obvious truths doesn't by itself get you a conclusion.
Example 6 You shouldn't eat the fat on your steak. Haven't you heard that
cholesterol is bad for you?
SECTION C The Guide to Repairing Arguments 65
Analysis The conclusion is the first sentence. But what are the premises? The
speaker's question is rhetorical, meant to be taken as an assertion: "Cholesterol is
bad for you." But that alone won't give us the conclusion. We need something like
"Steak fat has a lot of cholesterol" plus the obvious standard for that "should":
"You shouldn't eat anything that's bad for you." Premises like these are so well
known that we don't bother to say them. This argument is O.K.
Example 7 I totally don't support prohibiting smoking in bars—most people who go to
bars do smoke and people should be aware that a bar is a place where a lot of people go to
have a drink and smoke. There are no youth working or attending bars and I just don't
believe you can allow people to go have a beer but not to allow people to have a cigarette—
that's a person's God-given right.
Gordy Hicks, City Councilor, Socorro, N.M., reported in El Defensor Chieftain, 7/24/2002
Analysis The conclusion here needs to be stated: "Smoking should not be
prohibited in bars."
That prescriptive claim needs some standard. The unstated one here seems to
be that society should not establish sanctions against any activity that doesn't corrupt
youth or create harm to others who can't avoid it. The argument is just as good
without the appeal to God, so we can ignore that. If it turns out that Hicks really
does think the standard is theological, then the argument he gave isn't adequate.
You can't get a prescriptive conclusion from only descriptive premises:
"is" does not imply "ought."
Example 8 You're going to vote for the Green Party candidate for President?
Don't you realize that means your vote will be wasted?
Analysis Where's the argument here? These are just two questions.
If you heard this, you'd certainly think that the speaker is trying to convince
you to believe "You shouldn't vote for the Green Party candidate for President."
And the speaker is giving a reason to believe that: "Your vote will be wasted." This
is an implicit argument.
The argument sounds pretty good, though something is missing. A visitor from
Denmark may not know "The Green Party candidate doesn't have a chance of
winning." But even then, she could ask "So?". The argument is missing the glue
that links the premises to the conclusion. We'd have to fill in the argument further:
"If you vote for someone who doesn't have a chance of winning, then your vote will
be wasted." And when we add that premise, we see the argument that used such
"obvious" premises is really not very good. Why should we believe that if you vote
for someone who doesn't stand a chance of winning then your vote is wasted? If that
were true, then who wins is the only important result of an election, rather than, say,
making a position understood by the electorate. At best we can say that when the
unstated premises are added in, we get an argument one of whose premises needs a
66 CHAPTER 4 Repairing Arguments
substantial argument to convince us that it is true. Trying to repair arguments can
lead us to unstated assumptions about which the real debate should be.
Example 9 Cats are more likely than dogs to carry diseases harmful to humans.
Cats kill songbirds and can kill people's pets. Cats disturb people at night with their
screeching and clattering in garbage cans. Cats leave paw prints on cars and will
sleep in unattended cars. Cats are not as pleasant as dogs and are owned only by
people who have satanic affinities. So there should be a leash law for cats just as
much as for dogs.
Analysis This letter to the editor is going pretty well until the next to last sentence.
That claim is a bit dubious, and the argument will be better without it. So we
should delete it. Then, by adding some obvious claims that glue the premises to the
conclusion by ruling out other possibilities, we'll have a good argument.
Example 10 In a famous speech, Martin Luther King Jr. said:
"I have a dream that one day this nation will rise up and live out the true
meaning of its creed: 'We hold these truths to be self-evident—that all men are
created equal.' . . . I have a dream that one day even the state of Mississippi, a
desert state sweltering with the heat of injustice and oppression, will be
transformed into an oasis of freedom and justice. I have a dream that my four
little children will one day live in a nation where they will not be judged by the
color of their skin but by the content of their character."
. . . King is also presenting a logical argument... the argument might be
stated as follows; "America was founded on the principle that all men are
created equal. This implies that people should not be judged by skin color,
which is an accident of birth, but rather by what they make of themselves ('the
content of their character'). To be consistent with this principle, America should
treat black people and white people alike."
David Kelley, The Art of Reasoning
Analysis The rewriting of this passage is too much of a stretch—putting words in
someone's mouth—to be justified. Where did David Kelley get "This implies . . ."?
Stating my dreams and hoping others will share them is not an argument. Martin
Luther King, Jr. knew how to argue well and could do so when he wanted. We're
not going to make his words more respectable by pretending they're an argument.
&n
bsp; Not every good attempt to persuade is an argument.
Example 11 Alcoholism is a disease, not a character flaw. People are genetically
predisposed to be addicted to alcohol. An alcoholic should not be fired or
imprisoned, but should be given treatment.
Treatment centers should be established, because it is too difficult to overcome
the addiction to alcohol all by oneself. The encouragement and direction of others is
what is needed to help people, for alcoholics can find the power within themselves to
fight and triumph over their addiction.
SECTION C The Guide to Repairing Arguments 67
Analysis On the face of it, "Alcoholism is a disease, not a character flaw"
contradicts "Alcoholics can find the power within themselves to fight and triumph
over their addiction." Both these claims are important premises for the conclusion
"Treatment centers should be established." When premises contradict each other
and can't be deleted, there's no way to repair the argument.
Example 12 U.S. citizens are independent souls, and they tend to dislike being forced to
do anything. The compulsory nature of Social Security therefore has been controversial
since the program's beginnings. Many conservatives argue that Social Security should be
made voluntary, rather than compulsory.
Brux and Cowen, Economic lssues and Policy
Analysis The first two sentences look like an argument. But the first sentence is
too vague to be a claim. And even if it could be made precise, we'd have an
explanation, not an attempt to convince. Don't try to repair what isn't an argument.
Example 13 It is only for the sake of profit that any man employs capital in the support
of industry; and he will always, therefore, endeavour to employ it in the support of that
industry of which the produce is likely to be of greatest value, or to exchange for the greatest
quantity either of money or of other goods.
Adam Smith; The Wealth of Nations
Analysis The argument is valid, but its single premise is false. Lots of other
considerations about where to invest money matter to many people: convenience,
social responsibility So there's no way to repair it, and it's bad.
Example 14 When Dick put out the dry dog food that Spot usually won't eat, Spot
ran over and right away ate it. So Spot was hungry.
Analysis The conclusion is subjective. To have a good argument, we also need a
premise such as "When a dog races to eat food that he normally doesn't eat, then he
is hungry," which is plausible and makes this a good argument. That subjective
claim is the link between the observed behavior and the inferred state of mind. Often
an assumption linking behavior to thoughts is needed to make an argument good.
Example 15 None of Dr. E's students are going to beg in the street. 'Cause only
poor people beg. And Dr. E's students will be rich because they understand how to
reason well.
Analysis This is a superb argument!
68 CHAPTER 4 Repairing Arguments
We've seen how to repair some arguments. And just as important, we've seen
that some arguments can't be repaired.
Unrepairable arguments We don't repair an argument if:
• There's no argument there.
• The argument is so lacking in coherence that there's nothing obvious to add.
• A premise it uses is false or dubious and cannot be deleted.
• Two of its premises are contradictory, and neither can be deleted.
• The obvious premise to add would make the argument weak.
• The obvious premise to add to make the argument strong or valid is false.
• The conclusion is clearly false.
D. Relevance
Tom is making an argument (the second question is rhetorical):
Environmentalists should not be allowed to tell us what to do.
The federal government should not be allowed to tell us what to do.
Therefore, we should go ahead and allow logging in old-growth forests.
When the argument is put this way, it seems obvious to us that Tom has confused
whether we have the right to cut down the forests with whether we should cut them
down. Tom's proved something, just not the conclusion.
Sometimes people say an argument like Tom's is bad because his premises are
irrelevant to the conclusion. They say an argument is bad if in response to one or
more premises your reaction is "What's that got to do with anything?" or "So?"
What would you do if someone told you a claim you made is irrelevant? You'd
try to show that it is relevant by adding more premises to link it to the conclusion.
EXERCISES for Sections A-D 69
The trouble is that the premises needed to make the claim relevant are not obvious to
the other person. When we say that a premise is irrelevant to the conclusion, all
we're saying is that it doesn't make the argument any better, and we can't see how to
add anything plausible that would link it to the conclusion. And when we say that all
the premises are irrelevant, we're saying that we can't even imagine how to repair
the argument.
A premise is irrelevant if you can delete it and the argument isn't any weaker.
Exercises for Sections A-D
1. Why add premises or a conclusion? Why not take arguments as they are?
2. State the Principle of Rational Discussion and explain why we are justified in adopting it
when we reason with others.
3. What should you do if you find that the Principle of Rational Discussion does not apply
in a discussion you are having?
4. You find that a close friend is an alcoholic. You want to help her. You want to convince
her to stop drinking. Which is more appropriate, to reason with her or take her to an
Alcoholics Anonymous meeting? Explain why.
5. Since many people often don't satisfy the Principle of Rational Discussion, why not just
use bad arguments to fit the circumstances?
count as a suitable unstated premise.
7. When can't we repair an argument?
8. When you show an argument is bad, what does that tell you about the conclusion?
9. a. What is an indicator word?
b. List at least five words or phrases not in the chart that indicate a conclusion.
c. List at least five words or phrases not in the chart that indicate premises.
d. List five more words or phrases that show an attitude toward a claim or argument.
e. Bring in an argument from some source that uses indicator words.
10. Mark which of the blanks below would normally be filled with a premise (P) and which
with a conclusion (C).
a. (i) _, (ii) , (iii) , therefore (iv) .
b. (i) , since (ii) , (iii) , and (iv) .
c. Because (i) , it follows that (ii) and (iii) .
d. Since (i) and (ii) , it follows that (iii) , because (iv) .
e. (i) and (ii) , and that's why (iii) .
f. Due to (i) and (ii) , we have (iii) .
g. In view of (i) , (ii) , and (iii) we get (iv) .
70 CHAPTER 4 Repairing Arguments
h. From (i) and (ii) , we can derive (iii) .
i. If (i) , then it follows that (ii) , for (iii) and (iv).
11. How should we understand the charge that a premise is irrelevant?
Here are some of Tom's homeworks on repairing arguments.
&nbs
p; Anyone who studies hard gets good grades. So it must be that Zoe studies hard.
Argument! (yes or no) Yes.
Conclusion (if unstated, add it): Zoe must study hard.
Premises: Anyone who studies hard gets good grades.
Additional premises needed to make it valid or strong (if none, say so):
Zoe gets good grades.
Classify (with the additional premises): valid strong weak
Good argument! (Choose one and give an explanation.)
• It's good (passes the three tests). with the added premise.
• It's valid or strong, but you don't know if the premises are true,
so you can't say if it's good or bad.
• It's bad because it's unrepairable (state which of the reasons apply).
'Hpl first, "must" is an indicator word. The conclusion is "Zoe studies hard."
"Even then, Zoe couldget good.grades and not study hard if she's very bright.
It's the obvious-premise to add, ait right, but it makes the argument weak.
The argument is unrepairable. It's just like 'Example 2 on p. 63.
Celia must love the coat Rudolfo gave her. She wears it all the time.
Argument! (yes or no) Yes.
Conclusion (if unstated, add it): Celia loves the coat Rudolfo gave her.
Premises: She wears it all the time.
Additional premises needed to make it valid or strong (if none, say so):
Anyone who wears a coat all the time loves it.
Classify (with the additional premises): valid strong X weak
Good argument! (Choose one and give an explanation.)
• It's good (passes the three tests). with the added premise.
• It's valid or strong, but you don't know if the premises are true,
so you can't say if it's good or bad.
• It's bad because it's unrepairable (state which of the reasons apply).
you've confused whether an argument is valid or strong with whether it's good.
'With your added premise, the argument is indeed valid. 'But the premise you
added is clearly false. 'Weakening it to make the argument only strong won't
do— the person making the argument intended it to be valid (that word "must" in
the conclusion). So the argument is unrepairable because the obvious premise
to add to make it valid is false.
EXERCISES for Sections A-D 71
I got sick after eating shrimp last month. Then this week again when I ate