vocabulary chapter 1

Question 1

argument

Answer 1

a set of statements, one of which, called the conclusion, is affirmed on the basis of the others, which are called the premises.

Question 2

logic

Answer 2

the study of methods for evaluating whether the premises of an aregument adequately support (or provide good evidence for) its conclusion

Question 3

valid argument

Answer 3

has this essential feature: It is necessary that if the premies are true, then the conclusion is true.

Question 4

invalid argument

Answer 4

has this essential feature: It is not necessary that if the premises are true, then the conclusion is true.

Question 5

unsound argument

Answer 5

is one that either is invalid or has at least one false premise.

Question 6

sound argument

Answer 6

has two essential features: It is valid, and all its premises are true.

Question 7

deductive logic

Answer 7

is the part of logic that concerns tests for validity and invalidity

Question 8

term

Answer 8

is a word or phrase that stands for a class of things, such as the class of oaks or the class of trees.

Question 9

substitution instance

Answer 9

an argument that results from the uniformly replacing letters with terms in an argument

Question 10

argument form

Answer 10

a pattern of reasoning

Question 11

counterexample

Answer 11

a substitution instance whose premises are well-known truths and whose conclusion is a well-known falsehood.

Question 12

antecedent

Answer 12

the if-clause of a conditional

Question 13

consequent

Answer 13

the then-clause of a conditional

Question 14

stylistic variants

Answer 14

alternate ways of saying the same thing

Question 15

modus ponens

Answer 15

(valid) If A, then B. A. so, B.

Question 16

modus tollens

Answer 16

(valid) If A, then B. Not B. So, not A.

Question 17

hypothetical syllogism

Answer 17

(valid) If A, then B. If B, then C. So, if A, then C.

Question 18

disjunctive syllogism

Answer 18

Either A or B. Not A. So, B.

Question 19

constructive dilemma

Answer 19

Either A or B. If A, then C. If B, then D. So, either C or D.

Question 20

denying the antecedent

Answer 20

(invalid) If A, then B. Not A. So, not B.

Question 21

affirming the consequent

Answer 21

(invalid) If A, then B. B. So, A.

Question 22

strong argument

Answer 22

has this essential feature: It is probable (but not necessary) that if its premises are true, then its conclusion is true.

Question 23

weak argument

Answer 23

has this essential feature: It is not probable that if its premises are true, then its conclusion is true.

Question 24

arguments from authority

Answer 24

R is a reliable authority regarding S. R sincerely asserts that S. So, S.

Question 25

arguments from analogy

Answer 25

Object A is similar to object B. B has property P. So, A has property P also.

Question 26

cogent argument

Answer 26

has two essential features; It is strong, and all its premises are true.

Question 27

uncogent argument

Answer 27

is one that is either (a) weak or (b) strong with at least one false premise.

Question 28

inductive logic

Answer 28

concerns tests for strength and weakness