4 Categorical Propositions

1. 4 Categorical Propositions 4.2 QUALITY, QUANTITY, AND DISTRIBUTION

2. Quantity, Quality, and Distribution Quantities: there are just two quantities: 1 Universal (All or None) 2 Particular (Some … at least one). Qualities: there are just two qualities: 1 Affirmative 2 Negative

3. Quantity, Quality and Distribution Proposition Letter Name Quantity Quality All S are P A Universal Affirmative No S are P E Universal Negative Some S are P I Particular Affirmative Some S are not P O Particular Negative Quantity and Quality are properties of Propositions. A proposition is what a sentence asserts, or what we assert with a sentence. ‘I love the girl’ and ‘Puellam Amo’ are two different sentences that assert the same proposition.

4. Quantity, Quality, and Distribution Distribution is a property of terms, not propositions. A term is distributed if the proposition asserts something about every member of the class the term refers to, so… In ‘All S are P’, something is asserted about every member of the class referred to by the term S, and so S is distributed. For instance, All Salads are Priced to sell … something is asserted about every salad, but not about everything that is priced to sell (on sale). ‘All S are P’ assigns or distributes a property to every member of S (being priced to sell)

5. Quantity, Quality, and Distribution All S are P can be symbolized like this: S P

6. Quantity, Quality, and Distribution No S are P looks like this: ‘No S are P’, on our grocery interpretation, says something about everything Priced to sell, and every Salad. Therefore, both S and P are distributed. S P

7. Quantity, Quality, and Distribution Some S are P: This says that at least one member of S is also a P (at least one salad is priced to sell). This “I” proposition asserts something about at least one member of S and at least one member of P, so neither term is distributed. S* P

8. Quantity, Quality and Distribution Some S are not P: This propositions asserts that at least one Salad is not Priced to sell (it says nothing about all salads, but it does say something about all the sale items: none of them is that particular salad—or subclass of salads). S* P

9. Quantity, Quality and Distribution Summary … All SD are P No SD are PD Some S are P Some S are not PD Proposition Letter Name Quantity Quality Distribution All S are P A Universal Affirmative Subject only No S are P E Universal Negative Sub & Pred Some S are P I Particular Affirmative Neither Some S are not P O Particular Negative Predicate only