Chapter 1 - Basic Concepts

Question 1

What is an argument?

Answer 1

A set of statements: the conclusion and the premises. The conclusion is affirmed on the basis of the premises.

Question 2

What is Logic?

Answer 2

Study of methods for evaluating whether the premises of an argument adequately support (or provide good evidence for) its conclusion.
(Study of methods for evaluating arguments.)

Question 3

What is a valid argument?

Answer 3

It is necessary that if the premises are true, then the conclusion is true. (Premises completely support the argument.)

Question 4

What is an invalid argument?

Answer 4

It is not necessary that if the premises are true, then the conclusion is true.

Question 5

What is a sound argument?

Answer 5

It is valid, and all its premises are true.

Question 6

What is an unsound argument?

Answer 6

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

Question 7

What is deductive logic?

Answer 7

Concerns tests for validity and invalidity.

Question 8

What is an argument form?

Answer 8

A pattern of reasoning - some valid, some not. The validity of an argument is guaranteed by its form - does not depend on its content.

Question 9

What is a substitution instance of an argument form?

Answer 9

An argument that results from uniformly replacing letters in an argument form with terms (or statements). Must be uniform.

Question 10

Modus Ponens

Answer 10

(mode of positing)
If A, then B.
A.
So, B.

Question 11

Modus Tollens

Answer 11

(mode/way of removing)
If A, then B.
Not B.
So, Not A.

Question 12

Denying the Antecedent

Answer 12

If A, then B.
Not A.
So, Not B.

Question 13

Affirming the Consequent

Answer 13

If A, then B.
B.
So, A.

Question 14

Hypothetical syllogism

Answer 14

If A, then B.
If, B then C.
So, if A, then C.

Question 15

Disjunctive syllogism

Answer 15

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

Question 16

Constructive dilemma

Answer 16

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

Question 17

A term?

Answer 17

A word or phrase that stands for a class or set of things.

Question 18

Counter example

Answer 18

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

Question 19

Conditional statements

Answer 19

if-then statements. (Hypothetical in nature.)

Question 20

“If” clause is the?

Answer 20

Antecedent

Question 21

“Then” clause is the?

Answer 21

Consequent

Question 22

Strong argument

Answer 22

Probable (not necessary) that if premises are true, then the conclusion is true.(Inductive)

Question 23

Weak argument

Answer 23

It is not probably that if its premises are true, then its conclusion is true.(Inductive)

Question 24

Cogent argument

Answer 24

It is strong and all its premises are true.(Inductive)

Question 25

Uncogent argument

Answer 25

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

Question 26

Inductive logic

Answer 26

Methods of evaluating arguments for strength and weakness.

Question 27

Using forms to test validity

Answer 27

1. Identify component statements, labeling with capital letter.
2. Rewrite using cap. letters.
3. Identify famous forms & evaluate for validity. If no famous forms, construct counterexample.

Question 28

Invalid arguments:

Answer 28

Strong arguments w/ all premises true are cogent.
Strong arguments w/ atleast 1 false premise is uncogent.
Weak arguments are all uncogent.