Exercise 6.1
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Chapter 6
Exercise 6.1
Part I
1. C 21. B (C R)
2. A • N 22. (B C) R
Exercise 6.1
Part II
1. R
F 11. I
(M • N)
Part III
1. WFF 6. WFF
Exercise 6.2
Part I
1. Dot 6. Tilde
Part II
1.
H False 9.
(J
W) True
Part III
1. False 14. True
Exercise 6.2
Part IV
1. True 9. False
Exercise 6.3
Part I
1. Tautologous 9. Contingent
Part II
1. Logically equivalent 9. Logically equivalent
Part III
1. Carlson’s prediction is false (self-contradictory).
Exercise 6.3
Exercise 6.4
Part I
1. N
S 6. D
Exercise 6.4
Part II
1. Valid 14. Valid
Part III (The letters used in the translations are underlined in the text.)
Android Rights
“I just came from Professor Shaw’s class in the Philosophy of Human Nature,” Nick says to his
friend Erin, as he meets her in the hallway. “We discussed the question of whether an android
could be a person and whether they have rights.
“No they’re not,” Erin says. “If an android is rational, then it’s conscious, and if it’s
conscious, then it has reflective mental activity—it can reflect on its own act of thinking. But no
android can do that, so it’s not rational.”
Exercise 6.4
God could infuse a soul into it, then it could have a soul. Now an android is material and God
could infuse a soul into an android—after all, God can do anything. Thus, an android could have
a soul.”
“Well,” he says, “whatever we do is caused by our biological makeup or by our social
conditioning. If it’s caused by our biological makeup, then it’s determined. If it’s caused by our
“Well, I don’t know what it means for our actions to be influenced by something yet not
be determined,” Nick replies. “If X is influenced by Y, then X is caused by Y, and if X is caused
Exercise 6.4
Exercise 6.5
Part I
1. D = True 14. G = Unknown, B = Unknown
Part II
8. Invalid
Part III
1. Inconsistent 6. Inconsistent
Exercise 6.6
Exercise 6.6
Part I
The exercises marked with an asterisk must be rewritten. See below.
Part II
1. B
G 5. D
H
9. (S
D) • (I
D) 14. I
A
11. P
W 17.
C
A
Part III
1. (S
M) • (
S
F)
Exercise 6.6
2. (V
F) • (H
L)
3. (C
R) • (W
R) Rewritten: (C
R) • (W
R)
The disjunctive premise is a tautology, so it is impossible to escape between the horns.
4. (C
S) • (E
S) Rewritten: (C
S) • (E
S)
Exercise 6.6
If corporations spend money to neutralize their toxic waste, then the environment will be
5. (P
M) • (
P
S)
6. (D
S) • (M
T)
7. (C
L) • (J
B)
Exercise 6.6
9. (A
R) • (E
R) Rewritten: (A
R) • (E
R)
10. (P
R) • (T
E)
Part IV A Little Help From a Friend
“I can only talk for a minute,” Liz says to her friend Amy. “I have this bio mid term
tomorrow, and I’m afraid I’m going to fail it.”
“Okay,” Amy replies. “I’ll cut out after a minute or two. But why are you so afraid?”
Exercise 6.6
Liz stares at the little orange pill. “Adderall is for attention deficit disorder. You don’t
have that, do you?”
“No” says Amy. “I got the tab from my boyfriend, Zach, who talked the health clinic out
of a whole bottle by faking ADD.”
“Wow,” says Liz. “Do you think it’s safe for me to take it?”
She thinks for a moment and sighs. “Either I take the Adderall or I don’t. If I take it, I’ll
feel like I cheated, but if I don’t take it, I’ll fail the test. Thus, I’ll feel like I cheated, or I’ll fail
the test. Either way, I lose.”
“Okay,” says Amy. “But maybe your problem isn’t as bad as you think. Consider this:
Older people take drugs all the time to help their memory and their sex lives. If it’s okay for
them to take those drugs—and it is—then it’s okay for you to take the Adderall. You shouldn’t
sweat it.”
Exercise 6.6
“Not quite,” says Liz. “Coffee and Red Bull aren’t really comparable to Adderall—at
least not if it’s as good as you say it is. Suppose that I’m faced with this option: Either I drink
lots of coffee and Red Bull, or I take the Adderall. I would say no to the coffee and Red Bull
because it’s less effective, and it leaves me frazzled. Thus, I would take the Adderall. See, the
two are not the same.”
“The problem with that line of reasoning,” Liz observes, “is that using light bulbs and
cell phones doesn’t put anyone at a competitive advantage. Everyone uses them, so we’re all on
an equal footing. But not every student uses Adderall to pass a test. If everyone used it, I would
have no problem with it. But not everyone uses it, so I do have a problem.”
Part V
1. If human organs are given first to registered donors, then more people will register as
2. If we remain on standard time, then the grass will get one hour less sunlight. If the grass
3. If the religious right is consistent in its opposition to killing, then it seeks to abolish the
death penalty. The religious right does not seek to abolish the death penalty. Therefore,
Exercise 6.6
4. If group problem solving is important, then we should not place emphasis on individual
testing. Group problem solving is important. Therefore, we should not place emphasis on
5. If voluntary school prayer makes our children more moral, then mandatory church
6. If America replaces the diseased hearts of old white men but refuses to feed school
children, pay women adequately, or educate adolescents, then America is doomed.
7. If we close the library at Central Juvenile Hall, then delinquents will be deprived of an
opportunity to read. If delinquents are deprived of an opportunity to read, then they will
8. If the death penalty deters at least one person form becoming a murderer, then it is
justified. The death penalty does deter at least one person from becoming a murderer.
Exercise 6.6
9. If parents should be allowed to veto their minor daughter’s abortion, then they should also
10. If viewing adult videos leads to violent sex crimes, then there are over a million violent sex