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 (384-322 BCE)

Categorical Propositions (pp. 142-144)

• Categorical Propositions state relations among classes of objects.

• Quantity– Universal– Particular– Singular

• Quality– Affirmative– Negative

Categorical Propositions (pp. 142-144)

• 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. 142-144)

• 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.