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Flashcards in Chapter 4-4.5 Deck (12)
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1

Categorical proposition

- asserts that either all or part of the class denoted by the subject term is include or excluded from the class denoted by the predicate term

2

Standard form categorical proposition

1) quantifier -> all, no, some
2) subject term -> "members of the AMA" (before copula)
3) copula -> are and are not
4) predicate term -> "people holding degrees from recognized academic institutions" (after copula)

3

Propositions

Proposition................Quantity..............Quality
1) All S are P (A) ....Universal.....Affirmative
2) No S are P (E).....Universal..... Negative
3) Some S are P (I)...Particular .. Affirmative
4) Some S are not P (O).. Particular ... Negative

4

Existential Fallacy

- invalid merely because the premise does not exist
- Boolean standpoint (modern square)
- only used in contrary, subcontrary and subalternation (traditional) -> when universal goes to particular

5

Boolean stand point

- recognizes that particular statements make a positive assertion about existence

6

Venn Diagrams

A) shade S side
E) shade middle
I) x in the middle
O) x in S side

7

Modern Square of Opposition

- Boolean standpoint

Logically undetermined-> has truth value can't determine what it is
A---------E
I----------O

Contradictory -> opposite truth values

8

Testing immediate inferences

- one premise and one conclusion
- plug premise into modern square of opposition
- if it works then it's unconditionally valid regardless of existential fallacy
- illicit contrary, illicit subcontrary, illicit subalternation, illicit contraposition, illicit conversion

9

1) Conversion
2) illicit conversion

1) switch subject and predicate terms
2) E,I -> same truth value.
A,O -> undetermined truth value

10

Obversion

- change the quality
- replace predicate term with compliment (non P)
- all true

11

1) Contraposition
2) illicit contraposition

1) switch subject and predicate terms
- replace subject and predicate term with compliments

2) E,I -> undetermined truth value.
A,O -> determined truth value

12

Traditional Square of opposition

- contradictory -> opposite truth value
- contrary -> at least one is false (not both true). ... If a is true e is false. But if a is false e is either false or true
- subcontrary -> at least one is true (not both false)... If I is false O is true but if I is true A could be true or false
- subalternation -> truth flows downward, falsity flows upward