Understanding Args

Here are the answers to the handout on understanding arguments.

1. (P1) Fairdale has the best team.
(C) Fairdale will win the championship

2. (P1) The housing market is depressed.
(P2) Interest rates are low.
(C) It's a good time to buy a home.

3. (P1) China is guilty of extreme human rights abuses.
(P2) China refuses to implement democratic reforms.
(C) The U.S. should refuse to deal with the present Chinese government.

4. (P1) The results of the Persian Gulf War were obviously successful for the U.S. military.
(C) The U. S. military is both capable and competent.

5. (P1) Scientific discoveries are continually debunking religious myths.
(P2) Science provides the only hope for solving the many problems faced by humankind.
(C) Science provides a more accurate view of human life than does religion.

6. (P1) Freedom of speech and expressions are essential to a democratic form of government.
(P2) As soon as we allow some censorship, it won't be long before censorship will be used to silence the opinions critical of the government.
(P3) Once we allow some censorship, we will have no more freedom than the Germans did under Hitler.
(C) We must resist all effort to allow the government to censor entertainment.

7. (P1) I'm very good at my job.
(C) I deserve a raise.

8. (P1) Jesse is one year old.
(P2) Most one-year-olds can walk.
(C) Jesse can walk.

9 (P1) The revocation of the 55 mph speed limit has resulted in an increased number of auto fatalities.
(C) we must alleviate this problem with stricter speed limit enforcement.

10. (P1) The last person we hired from Bayview Tech turned out to be a bad employee.
(C) I'm not willing to hire anybody else from that school again.

11. (P1) Maebe didn't show up for work today.
(P2) Maebe has never missed work unless she was sick.
(C) Maebe is probably sick today.

11. (P1) The United States, as the most powerful nation in the world, has a moral obligation to give assistance to people who are subjected to inhumane treatment.
(P2) The ethnic Albanians were being persecuted in Kosovo.
(C) It was proper for the U.S. to become involved in the air campaign against Kosovo.

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Hat tip: I took some of the examples (with some revisions) from Beth Rosdatter's website, and some (with some revisions) from Jon Young's website.

Deductive Args

Here are the answers to the handout on deductive arguments that we went over in class.

1) All bats are mammals.
All mammals live on earth.
All bats live on earth.

Valid, Sound

2) All students in here are mammals.
All humans are mammals.
All students in here are humans.

Invalid (what if a dog were a student in our class?),
Unsound (because it's invalid)

3) (from Stephen Colbert)
Bush is either a great prez or the greatest prez.
Bush isn’t a great prez.
Bush is the greatest prez.

Valid, Unsound (questionable premises)

4) All BCC students are humans.
Most humans are shorter than 7 feet tall.
Most BCC students are shorter than 7 feet tall.

Invalid (there could be a lot of tall BCC students even if most humans aren't tall), Unsound (because it's invalid)

5) Some people are funny.
Sean is a person.
Sean is funny.

Invalid (only some are funny, so I don't have to be funny), Unsound (because it's invalid)

6) If Sean sings, then students cringe.
Sean is singing right now.
Students are cringing right now.

Valid, Unsound (false second premise: I'm not singing right now)

7) All email forwards are annoying.
Some email forwards are false.
Some annoying things are false.

Valid, Unsound (questionable first premise)

8) If Sean sings, then students cringe.
Sean isn't singing right now.
Students aren't cringing right now.

Invalid (students could cringe for a different reason), Unsound (it's invalid)

9) All bats are mammals.
All bats have wings.
All mammals have wings.

Invalid (bad structure), Unsound (because it's invalid)

10) If Sean sings, then students cringe.
Students aren't cringing right now.
Sean isn't singing right now.

Valid, Unound (first premise is questionable)

11) All dads have beards.
All bearded people are mean.
All dads are mean.

Valid, Unsound (premise 1 is false and premise 2 is questionable)

12) If Sean sings, then students cringe.
Students are cringing right now.
Sean is singing right now.

Invalid (I don't have to sing for students to cringe), Unsound (it's invalid, and false second premise)

13) Mexico borders oceans on the east and west.
USA borders oceans on the east and west.
Guatemala borders oceans on the east and west.
Australia borders oceans on the east and west.
Most countries border oceans on the east and west.

Invalid (the premises don't guarantee the conclusion), Unsound (it's invalid)

(More on Sisyphus)