CHAPTER 5 ■ Deep Analysis
knowledge (“studies”) and to show that we have knowledge instead of just
a hunch. That point is lost if we drop the assuring terms.
Unfortunately, there is no mechanical method for determining when
guarding or assuring terms and phrases can be dropped, or whether certain
sentences are unnecessary tangents or repetition. We simply have to look
closely at what is being said and think hard about what is needed to support
the conclusion. It takes great skill, care, and insight to pare an argument
down to its essential core without omitting anything that would make it better. And that is the goal: If you want to understand someone’s argument,
you should try to make that argument as good as it can be. You should interpret it charitably. Distorting and oversimplifying other people’s arguments might be fun at times and can win points in debates, but it cannot
help us understand or learn from other people’s arguments.
In the quotation above, is it fair to drop “I think” from the start of Edwards’s
sentences “I think these are decisions the states should have the power to make”
and “I think that’s wrong—that power should not be taken away from the
states“? Why or why not? Is this phrase “I think” used for guarding or assuring
or some other purpose in this context? Explain why Edwards adds these words.
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.
- Philadelphia is rich in history, but it is not now the capital of the United
States, so the United States Congress must meet somewhere else.
- 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.
- I know that my wife is at home, since I just called her there and spoke to
her. We talked about our dinner plans.
- I’m not sure, but Joseph is probably Jewish. Hence, he is a rabbi if he is a
member of the clergy.
- Some students could not concentrate on the lecture, because they did not
eat lunch before class, although I did.
- 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 Democrat is likely to win, since experts agree that more women support him.
- It seems to me that married people are happier, so marriage must be a
good thing, or at least I think so.
premises) provide separate reasons for a conclusion, draw separate arrows
from each reason to the conclusion. When a conclusion of one argument is
a premise in another, put it in the middle of a chain. The whole diagram
together will then show how the parts of the argument fit together.
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.
- I know that Pat can’t be a father, because she is not a male. So she can’t be
a grandfather either.
- Either Jack is a fool or Mary is a crook, because she ended up with all of
- 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.
- 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.
- 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.
- 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.
- 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.
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
CHAPTER 5 ■ Deep Analysis
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
Suppressed Premises: A sister would be a sibling.
A brother is not a sister.
- Britney Spears is under age thirty-five. Therefore, she cannot run for
president of the United States.
- Nixon couldn’t have been president in 1950 because he was still in the Senate.
- 81 is not a prime number, because 81 is divisible by 3.
- There’s no patient named Rupert here; we have only female patients.
- Columbus did not discover the New World because the Vikings explored
Newfoundland centuries earlier.
- There must not be any survivors, since they would have been found by now.
- Lincoln could not have met Washington, because Washington was dead
before Lincoln was born.
- Philadelphia cannot play Los Angeles in the World Series, since they are
both in the National League.
- Mildred must be over forty-three, since she has a daughter who is thirtysix years old.
- He cannot be a grandfather because he never had children.
- That’s not modern poetry; you can understand it.
- Harold can’t play in the Super Bowl, because he broke his leg.
- Shaquille must be a basketball player, since he is so tall.
- Dan is either stupid or very cunning, so he must be stupid.
- Susan refuses to work on Sundays, which shows that she is lazy and
- Jim told me that Mary is a professor, so she can’t be a student, since
professors must already have degrees.
- This burglar alarm won’t work unless we are lucky or the burglar uses the
front door, so we can’t count on it.
- His natural talents were not enough; he still lost the match because he had
not practiced sufficiently.
THE METHOD OF RECONSTRUCTION
We can summarize the discussion so far by listing the steps to be taken in reconstructing an argument. The first two steps were discussed in Chapters 4
and 3, respectively.