LOGIC 1000A: QUIZ #1
Sept. 23, 2004
I) Short Answer (6 pts)
1. Could a cogent argument have a false conclusion? Explain.
Yes. A cogent argument is an inductive argument that is strong and has all
true premises. Since, a strong argument is one in which it is impossible for
the premises to be true and the conclusion unlikely, the conclusion of a
cogent argument is likely true. Although unlikely, it is nonetheless possible
for the conclusion to be false.
2. Explain the difference between an argument and a conditional statement.
An argument is a set of statements, one or more of which – the premises –
are claimed to be evidence for another statement – the conclusion. The
premises and the conclusion are all asserted/ claimed to be true by the
arguer. A conditional statement is a single statement of the form “if p the q”.
Neither the antecedent – “p” – nor the consequent –“q” – are asserted. The
issuer of the statement asserts only that there is a conditional relation
between them.
II) Standardization (6 pts)
Standardize each of the following arguments.
3. If a tree falls in the forest, it makes a sound. But since there are no unheard
sounds, it follows that trees don’t fall when no one is around. After all, you can’t
hear what you’re not near.
P1: If a tree falls in the forest, it makes a sound
P2: There are no unheard sounds
P3: You can’t hear what you’re not near.
C: Trees don’t fall when no one is around
4. Logic is useless. It’s too abstract to apply to your other courses, and no one
understands what you’re talking about when you try to use it in conversation. So no
one should take logic courses. Moreover, it’s too hard to get a good grade in.
P1: Logic is useless
P2: Logic is too abstract to apply to your other courses
P3: No one understands what you’re talking about when you try to use logic
in conversation.
P4: Logic is too hard to get a good grade in
C: No one should take logic courses
III) Argument Diagrams (8 pts)
Using the indicated numbering, diagram the following argument.
5. (1) Alward is difficult to talk to because (2) he is obscure and a little insulting.
And (3) Alward is difficult to cook for because (4) he is a very picky eater. And
since (1) he is difficult to talk to and (3) hard to cook for, (5) Alward gets very few
dinner party invitations.
(2)

(1)
(4)

(3)

(5)
6. (1) Fido is a dog; therefore, since (2) all dogs are smelly beasts, (3) Fido smells
bad. And because (4) unpleasant odors are a sign of uncleanliness, (5) all smelly
beasts need baths. Consequently (6) Fido needs a bath.
(1)
(2)

(3)

(6)
(4)

(5)