Answers to Chapter Three Exercises on Argument Analysis
Exercise 3.3:
1. Signal Words: So, because
Conclusion: I’m going to need a ride home.
2. Signal Words: It is reasonable to suppose
Conclusion: Animals feel pain and pleasure as we humans do
3. Signal: ‘So’
Conclusion: “It is lawful to do good on the Sabbath
4. Signal Word: Therefore
Conclusion: Zest is the best soap available
5. Signal Word: because
Conclusion: In the next century, more and more people will turn to solar energy to heat
their homes.
6. Signal Word: Since
Conclusion; People who smoke cigarettes should be forced to pay for their own health
insurance.
7. No argument
8. Signal words: because, furthermore, rather
Conclusion: Even though spanking has ….. parents should not spank their children.
9. Signal Words: But, it follows then
Conclusion: Public schools ought to charge …. Responsible members of our society.
10. Signal Words: But, the second ‘since,’ we must conclude
Conclusion: The loss of Rice….has not been devastating.
11. Signal Words: So, the second ‘because’
Conclusion: Let’s all call in sick this Monday
12. Signal Words: Since, therefore, since
Conclusion: Capital punishment is not justified.
Exercise 3.4
1. Signal word: must
Unsupported premise: The victim, a vigorous 200-pound athlete, was strangled by the
murderer’s bare hands.
Supported premise: The murderer must have very well developed upper body strength.
Unsupported premise: The mother-in law is a frail 80 year-old woman.
Main Conclusion; The mother-in-law can’t be the murderer.
2. Signal words: So, so
Unsupported premise: Part of believing something is believing it is true.
Supported premise; If I were to do an inventory of my beliefs, they would all seem true to
me.
Main conclusion: It doesn’t make sense for me to say that some of my own beliefs are
false.
3. Signal word: So
Unsupported premise: I’ve learned on numerous occasions….that things I believed to be
true were really false.
Supported premise: I’ve been mistaken in the past.
Main conclusion: If I were to do an inventory of my beliefs, I probably wouldn’t notice
the false ones, but I’d still bet there are some on there somewhere.
4. Main conclusion: Nor is there anything smart about smoking.
Unsupported premises: Women who smoke have more spontaneous abortions
Women who smoke have more stillbirths
Women who smoke have more premature babies
Women who smoke have children whose later health may be
affected.
Supported premise: A woman who smokes is far more likely than her nonsmoking
counterpart to suffer from a host of disabling conditions.
5. Main conclusion: Certain traits must be common to all cancers.
Unsupported premises: All cancer cells have certain nutritional needs.
All could grow in soft agar cultures.
All could seed new solid tumors when transplanted into
experimental animals.
All contained drastically abnormal chromosomes.
Supported premise: Scientists have observed the same characteristics in what they
though were different cancer cells.
Exercise 3.6 : Implied conclusions
1. You may not stay in this country.
2. God is benevolent.
3. The battery in the remote is dead.
4. All orangutans suckle their young.
5. Software contains mistakes.
6. Censorship over the internet is useless.
Exercise 3.7: Implied premises
1. International terrorists are not U.S. citizens.
2. Network news is propaganda.
3. UCLA is the Pac 10 champion.
4. The internet has commercial potential.
5. Fads fade.
Exercise 3.9: Instead of premise support, I will label these blanks as either the
main conclusion, supported premise, or unsupported premise. See your
definitions and examples for these.
1. Unsupported premise and unsupported premise. So main conclusion.
2. Main conclusion, because supported premise, since unsupported premise.
3. Inasmuch as unsupported premise, main conclusion, for unsupported premise.
4. Unsupported premise. Therefore, since unsupported premise, main conclusion.
5. Unsupported premise. Therefore main conclusion, since unsupported premise.
6. Main conclusion. This follows from unsupported premise and unsupported premise.
Exercise 3.11:
1. (main conclusion)College education affects one’s earning potential, for
(unsupported premise) research shows that college graduates make more money over a
lifetime than non-college graduates do.
2. (unsupported premise)No diet I’ve ever tried has worked. So, (conclusion) this new
diet won’t help me lose weight.
3. (main conclusion) Bill must be a poor student since (unsupported premise) Bill
spends most of his time watching ESPN.
4. (unsupported premise) Because students come to school to learn, (main conclusion)
students should have no say in curriculum decisions.
Exercise 3.12:
1. implied conclusion: Cassius is dangerous.
2. implied conclusion: You should not abandon the theory of creation.
3. implied conclusion: Actions that are not voluntary (not done by a free agent) are not
worthy of praise or blame, and we are not responsible for them.