Chapter 7

Question 1

Deductive Entailment

Answer 1

e

Question 2

4 properties of Deductive Inference

Answer 2

1. Non-ampletive
2. All or nothing: All true premises and true conclusion (valid/cogent) or false
3. Truth Preserving: premises all true. conclusion 100% true
4. Erosion Proof:

Question 3

Categorical Syllogism

Answer 3

Deductive Argument: conclusion is inferred from two premises.

1. contains 3 terms
2. each term occurs in exactly 2 inferences

Question 4

Universal Affirmative

Answer 4

(A) All S are P

Question 5

Universal Negative

Answer 5

(E) No S are P

Question 6

Particular Affirmative

Answer 6

(I) Some S are P

Question 7

Particular Negative

Answer 7

(O) Some S are not P

Question 8

Square of Opposition

Answer 8

An arrangement of the 4 Categorical forms.

Question 9

Contradictory, contrary, sub-contrary

Answer 9

(of a given statement)
All S is P(A) contradictory to Some S is not P(O)
No S is P(E) contradictory to Some S is P(I)

Question 10

Contrary

Answer 10

(A) contrary to (E) : can’t both be true, but can both be false

ex:
All flowers are blue = false
No flowers are blue = false

Question 11

sub-Contrary

Answer 11

(I) sub-contrary to (O) : can both be true but can’t both be false
Some flowers are blue = true
Some flowers are not blue = true

Question 12

Distributed

Answer 12

(A) subject term = distributed. Predicate term = not.
(E) BOTH subject term and Predicate term is distributed
(I) NEITHER S or P is distributed
(O) subject term = not. Predicate term = distributed.

Question 13

stereotyping

Answer 13

Problem with Universal Affirmative (A)

• putting them into categories and making universal judgments about all or most members of the category.
  ex: All Canadians like snow.

Question 14

Major term

Answer 14

(predicate term)
Term that appears in the predicate position in the conclusion of the syllogism.
1. major term
2. minor term
3. conclusion

Question 15

Minor term

Answer 15

(subject term)
Term that appears in the subject position in the conclusion of a syllogism
- 2nd premise

Question 16

Middle term

Answer 16

Term that occurs in both premises of the syllogism and not the conclusion.

• enables us to logically deduce the premise to the conclusion.
• MUST be distributed in at least ONE premise

Question 17

Fallacy of the undistributed middle

Answer 17

Fallacy committed when the middle term of the syllogism is not distributed in at least 1 premise.

Question 18

Mood of syllogism

Answer 18

The letters A E I O make the mood

ex: 1. No heroes are cowards
2. Some soldiers are cowards
3. Therefore, some soldiers are heroes

Mood: E I I

Question 19

4 figures

Answer 19

(1)M-P
S-M
therefore S-P

(2) P-M
S-M
Therefore S-P

(3) M-P
M-S
therefore S-P

(4) P-M
M-S
therefore S-P

Question 20

Rules for testing Deductive Validity in a Categorical Syllogism

Answer 20

Rule #1: For a syllogism to be valid, the middle term must be distributed in at least one premise

Rule #2: For a syllogism to be valid, no term can be distributed in the conclusion unless that term is also distributed in at least one premise

Rule #3: For a syllogism to be valid, at least one premise must be affirmative

Rule #4: For a syllogism to be valid, if it has a negative conclusion, it must have a negative premise. And if it has one negative premise, it must also have a negative conclusion.

Rule #5: If a syllogism has two universal premises, it cannot have a particular conclusion and be valid.

Question 21

Steps for the Categorical Syllogism

Answer 21

1. Put into form
2. identify major term, minor term and middle term
3. Identify if each line is A E I or O
4. Identify what’s distributed
5. Identify the mood
6. Apply the rules. Is it valid or nah?

Question 22

Laughter is the best medicine

Answer 22

form:

All things that are laughter are things that are the best medicine

Question 23

What is a deductively valid argument?

Answer 23

If the premises are true. The conclusion also must be true.

types:
- affirming the antecedent
- Denying the consequence
- Hypothetical syllogism
- Disjunctive syllogism

Question 24

What is a deductively invalid argument?

Answer 24

if the premises are true but the conclusion is false.

types:
- Denying the antecedent
- Affirming the consequence

Question 25

Affirming the antecedent

Answer 25

(deductively valid argument) 
(modus ponens)
1. if P, then Q
2. P
3. therefore, Q

Question 26

Denying the consequence

Answer 26

(deductively valid argument) 
(modus tollens) 
1. If P, then Q
2. not P
3. therefore, not Q

Question 27

Hypothetical syllogism

Answer 27

(deductively valid argument)

Question 28

Disjunctive syllogism

Answer 28

(deductively valid argument)

1. Either P or Q
2. Not P
3. therefore Q.

Question 29

Denying the antecedent

Answer 29

(deductively invalid argument)

Question 30

affirming the consequence

Answer 30

(deductively invalid argument)