Chapter 13: Categorical Propositions

Categorical Syllogisms (p. 141) Review of deductive arguments –Form –Valid/Invalid –Soundness Categorical syllogisms concern relations among classes. They were first discussed by Aristotle ( BCE)

Categorical Propositions (pp ) Categorical Propositions state relations among classes of objects. Quantity –Universal –Particular –Singular Quality –Affirmative –Negative

Categorical Propositions (pp ) Four forms of categorical propositions –Universal Affirmative (A): All dogs are mammals. –Universal Negative (E): No cats are dogs. –Particular Affirmative (I): Some dogs are collies. –Particular Negative (O): Some dogs are not schnauzers.

Categorical Propositions (pp ) Standard form categorical propositions –It has a quantifier, which is either ‘all’, ‘no’, or ‘some’. –It has a subject term, which is immediately to the right of the quantifier. –It has a form of the verb ‘to be’, which is immediately to the right of the subject term. –It has a predicate term, which is immediately to the right of the verb.