Chapter 4 Flashcards
What are the four standard form categorical Propositions?
- All S are P
- No S are P
- Some S are P
- Some S are not P
“A” Standard form categorical propositions
All S are P.
Universal Affirmative
“E” Standard form categorical propositions
No S are P.
Universal Negative
“I” Standard form propositions
Some S are P.
Particular Affirmitive
“O” standard form categorical propositions
Some S are not P.
Particular Negative
Distribution
An attribute of the terms of a proposition. A term is said to be distributed if the proposition makes an assertion about every member of the class denoted by the term.
Distributed terms of categorical propositions
A = S term E = S and P term I = no term is dist. O = P term
Contradiction
cannot have the same truth value. If one is true, then the other must be false, and vice versa.
A and O
E and I
Contrariety
Contrary propositions cannot both be true at once but can both be false
A and E
Subcontrariety
Subcontrariety propositions cannot both be false at once but can both be true
I and O
Subalternation
If the subaltern is true, then its subaltern is true. If the subaltern is false, then its subaltern is undetermined
A and I
E and O
Subalternation
If the subaltern is true, then its subaltern is undetermined. If the subaltern is false, the its subaltern is false.
I and A
O and E
Modern Square of Opposition
The only relationship that matters is contradiction.
Conversion
S and P switch
valid for:
E and I
valid for A by limitation
Obversion
Quality cahnges, P takes prefix “non”. Valid for A, E, O, and I propositions.
Contraposition
S and P switch, each taking the prefix “non”. Valid for A and O. Valid to E propositions by limitation.
Quantifiers
“all,” “no,” “some,” – words to specify how much of the subject class is included.
Existential import
If the truth of the proposition requires a belief in the existence of members of the subject class
Copula
“are,” “are not,” – they link the subject term with the predicate term
Quality of Categorical Proposition
either affirmative or negative depending on whether it affirms or denies class membership
Quantity of Categorical Proposition
either universal or particular, depending on whether the statement makes a claim about every member or just some member of the class denoted by the subject term
Existential Fallacy
From the Boolean standpoint, a formal fallacy that occurs whenever an argument is invalid merely because the premise lacks existential import
