Chapter 4 Flashcards
What are the four standard form categorical Propositions?
- Quantifier
- Subject Term
- Copula
- Predicate term
“A” Standard form categorical propositions
All S are P.
Affirmitive
“E” Standard form categorical propositions
No S are P.
Negative
“I” Standard form propositions
Some S are P.
Affirmitive
“O” standard form categorical propositions
Some S are not P.
Negative
Distribution
An attribute of a proposition. A term is said to be distributed iff the statements assigns an attribute to 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.
