HW#2: Basic Concepts and Argument Analysis
1. Which of the following is a premise indicator word?
a. consequently
b. therefore
c. since
d. hence
2. Which of the following passages contains an argument?
I. Cellular phone services become cheaper every year and cellular phones themselves are getting progressively smaller.
II. Cellular phones will eventually replace traditional phones because they are more convenient and they look cooler.
III. Cellular phones will never replace traditional phones because traditional phones will always be cheaper, more reliable and more private than cellular phones.
a. I & II
b. III
c. II & III
d. all of the above
(II) and (III) are arguments, while (I) simply gives a few facts which could serve as premises in an argument, but don't here because there is no conclusion.
3. Which of the following propositions are true for all valid arguments?
a) The premises are true.
b) The conclusion is true.
c) If the premises are true the conclusion must be true.
d) all of the above
4. Which of the following propositions are true for all sound arguments?
a) The premises are true.
b) The conclusion is true.
c) If the premises are true the conclusion must be true.
d) All of the above
5. Which of the following statements are true?
a) An argument with many steps is at least as strong as its strongest step.
b) Inductive strength is a matter of degree.
c) The conclusion of an inductive argument follows necessarily from the premises.
d) All of the above
6. Which of the following statements are true?
a) An inductive argument can have false premises and still be strong.
b) Some valid arguments are not sound.
c) The validity of a deductive argument is determined by its form.
d) All of the above.
7. Which of the following statements is true of the actual practice of our legal system?
a) Committing a crime is a necessary condition for going to Jail.
b) Committing a crime is a sufficient condition for going to Jail.
c) Committing a crime is both a necessary and a sufficient condition for going to Jail.
d) Committing a crime is neither a necessary nor a sufficient condition for going to Jail.
Quite a few people had problems with this one, but the answer is (d). One can commit a crime without going to jail (one might shoplift without being caught, one might get caught without being arrested, one could be arrested without being found guilty at the trial, and one can be found guilty without actually doing time (given probation or having to pay a fine instead, etc.). Consequently, committing a crime certainly isn't a sufficient condition for going to jail. It isn't necessary either, since (as the system is actually practiced) there are (admittedly rare) cases where innocent people end up being convicted for crimes they didn't commit and then have to do time for it. Consequently, committing a crime isn't a necessary condition either.
8. Which diagram best represents the following argument:
"[1]We should go out Friday since [2] we won't have any money on Thursday, and [3] because it will be Christmas Eve, [4] lots of places will be closed on Saturday."
a) b) c) d)
I can't reproduce the diagrams here, but (a) is the right answer because [3] gives you reason to believe that [4] is true, and [2] and [4], taken together, give you reason to believe that [1] is true.
9. Which diagram best represents the following argument:
"[1] You should buy chicken instead of beef because [2] its cheaper than beef and [3] its lower in fat. [4] Besides its a lot easier to cook.."
a) b) c) d)
(c) is the correct answer in this case because [2], [3] and [4] each give one independent reason to believe that [1] is true.
10. Which diagram best represents the following argument?
"[1] You shouldn't go out drinking tonight because [2] if you go out, you won't be able to get up in the morning, and [3] you need to be up for a job interview at 9am."
a) b) c) d)
(b) is the correct answer in this case because [2] and [3], when taken together (but not independently) give one reason to believe [1] is true.