Definitions
Square of Opposition
Logical Equivalence
Taking relationships of equivalence
Translation
100

Class

A group of things that share a common attribute

100

Contradiction

Relationship between propositions of opposing quality and quantity. One must be true and the other must be false

100

Word used to designate a complementary class

Non

100

Obverse of No Avengers are D.C. Comics characters

All Avengers are non-D.C. Comics characters

100

When translating a sentence with an action verb add this suffix to the verb then make the noun you create the basis of the P term

"er"

200

Complementary Class

The group of items outside of a class

200

Contariety

The relationship between universal propositions of differing quality. Both cannot be true but both may be false.

200

Obverse is valid for

All propositions

200

Converse of Some Mandalorians are People

Some People are Mandalorians

200

Statements about one individual are translated as _________ propositions

Universals

300

Converse

Replacing the S term with the P term and replacing the P term with the S term

300

Subcontariety

The relationship between particular propositions of differing quality. Both may be true but both cannot be false.

300

Contrapositive is valid for

A and O

300

Contrapositive of All Elves are Dwarf-despisers

All non-Dwarf-despisers are non-Elves.

300

The three steps for translating a proposition into a categorical proposition

1. Identify quality/quantity

2. Identify verb

3. Identify S term and P term, modifying wording as necessary.

400

Obverse

A relationship of equivalence that occurs when the quality of the subject of a proposition is changed then the predicate is negated

400

Subimplication

The relationship between the universal and particular of the same quality. If the universal is true, the particular is true. If the universal is false, the particular is unknown.

400

Converse is valid for

E and I

400

Converse of Some Jedi are Force-users

Some force-users are Jedi

400

Translate: Nearly all the Ringbearers were corrupted.

Some Ringbearers were corrupted beings

500

Contrapositive

Reversing and negating both the S term and P term of the original proposition

500

Superimplication

The relationship between the particular and universal propositions of the same quality. If the particular is true, the universal is unknown. If the particular is false, the universal is false.

500

Steps for taking contrapositive

Obverse, converse, obverse

500

Contrapositive of Some Fellowship members are not unkind beings

Some non-unkind beings are non-Fellowship members

500

Translate: Only citizens can vote

All voters are citizens