Can a valid deductive argument ever have false premises?
EXERCISES Review Questions
1. Are all persuasive arguments valid? Recount a situation in which you tried to persuade someone of a view by using an argument. (p. 44)
2. Can a valid deductive argument ever have false premises? Why or why not? (p. 44)
3. Are the premises of a cogent argument always true? Is the conclusion always true? Explain. (p. 45)
4. What is the term designating a valid argument with true premises? a strong argument with true premises? (p. 45)
62 Á PART 2: MORAL REASONING
213006_03_039-064_r1_el.qxp:213006_03_039-064_r1_el 8/3/15 9:46 AM Page 62
5. Is the following argument form valid or invalid? Why or why not? (p. 45)
If p, then q. p. Therefore, q.
6. Is the following argument form valid or invalid? Why or why not? (p. 46)
If p, then q. If q, then r. Therefore, if p, then r.
7. What is the counterexample method? (p. 47) 8. What kind of premises must a moral argument
have? (p. 51) 9. What is the best method for evaluating moral
premises? (pp. 53–55) 10. Explain the method for locating implied
premises. (pp. 47–48)
Discussion Questions
1. Is it immoral to believe a claim without evidence? Why or why not?
2. If moral reasoning is largely about providing good reasons for moral claims, where do feelings enter the picture? Is it possible to present a good argument that you feel strongly about? If so, provide an example of such an argument.
3. Which of the following passages are arguments (in the sense of displaying critical reasoning)? Explain your answers. • If you harm someone, they will harm you. • Racial profiling is wrong. It discriminates
against racial groups, and discrimination is wrong.
• If you say something that offends me, I have the right to prevent you from saying it again. After all, words are weapons, and I have a right to prevent the use of weapons against me.
4. What is the difference between persuading someone to believe a claim and giving them reasons to accept it? Can a good argument be persuasive? Why or why not?
5. Why do you think people are tempted to use the straw man fallacy in disagreements on moral issues? How do you feel when someone uses this fallacy against you?
Argument Exercises
Diagram the following arguments. Exercises marked with an asterisk (*) have answers in Answers to Argument Exercises at the end of the text.
*1. If John works out at the gym daily, he will be healthier. He is working out at the gym daily. So he will be healthier.
2. If when you are in a coma you are no longer a person, then giving you a drug to kill you would not be murder. In a coma, you are in fact not a person. Therefore, giving you the drug is not murder.
*3. Ghosts do not exist. There is no reliable evidence showing that any disembodied persons exist anywhere.
4. If you smoke, your heart will be damaged. If your heart is damaged, your risk of dying due to heart problems will increase. Therefore, smoking can increase your risk of dying due to heart problems.
*5. The mayor is soft on crime. He cut back on misdemeanor enforcement and told the police department to be more lenient with traffic violators.
6. Grow accustomed to the belief that death is nothing to us, since every good and evil lie in sensation. However, death is the deprivation of sensation. Therefore, death is nothing to us.
*7. The president is either dishonest or incompetent. He’s not incompetent, though, because he’s an expert at getting self-serving legislation through Congress. I guess he’s just dishonest.
8. Most Republicans are conservatives, and Kurt is a Republican. Therefore, Kurt is probably a conservative. Therefore Kurt is probably
CHAPTER 3: EVALUATING MORAL ARGUMENTS Á 63
213006_03_039-064_r1_el.qxp:213006_03_039-064_r1_el 8/3/15 9:46 AM Page 63
opposed to increases in welfare benefits because most conservatives are opposed to increased welfare benefits.
*9. Can people without strong religious beliefs be moral? Countless people have been nonbelievers or nontheists and still behaved according to lofty moral principles; for example, the Buddhists of Asia and the Confucianists of China. Consider also the great secular philosophers from the ancient Greeks to the likes of David Hume and Bertrand Russell. So it’s not true that those without strong religious beliefs cannot be moral.
10. Jan is a student at Harvard. No student at Harvard has won a Pulitzer prize. Therefore, Jan has not won a Pulitzer.
*11. We shouldn’t pay the lawnmower guy so much money because he never completes the work, and he will probably just gamble the money away because he has no self-control.
12. Either Manny, Mo, or Jack crashed the car. Manny couldn’t have done it because he was sleeping in his room and was observed the whole time. Mo couldn’t have done it because he was out of town at the time and has witnesses to prove it. So the guy who crashed the car had to be Jack.