PHL Chapter 9

A - Universal Affrimative: All S are P

E - Universal Negation: No S are P

I - Particular Negation: Some S are P

O - Particular Negation: Some S are not P

The Categorical Operation Conversion: Switch the subject and predicate terms, what claims maintain logical equivalency afterward still? E-Claims & I-Claims

The Categorical Operation Obversion: Change from affirmative/negative and attach “non” to predicate term, what claims maintain logical equivalency afterward still? E-Claims, I-Claims, A-Claims, O-Claims

The Categorical Operation Contraposition:  Switch subject and predicate terms and attach “non” to each, what claims maintain logical equivalency afterward still? A-Claims, O-Claims

In Conversion, how are the claims?

• A-Claim: All S are P → All P are S

• E-Claim: No S are P → No P are S

• I-Claim: Some S are P → Some P are S

• O-Claim: Some S are not P → Some P are not S

In Obversion, how are the claims?

• A-Claim: All S are P → All P are S

• E-Claim: No S are P → No P are S

• I-Claim: Some S are P → Some P are S

• O-Claim: Some S are not P → Some P are not S

In Contraposition, how are the claims?

• A-Claim: All S are P → All non-P are non-S

• E-Claim: No S are P → No non-P are non-S

• I-Claim: Some S are P → Some non-P are non-S

• O-Claim: Some S are not P → Some non-P are not non-S