Peter Kreeft's Logic Text on Propositions (Part 1 of 2)

We'll be exploring Chapter Five, dealing with Propositions, from "Socratic Logic" by Peter Kreeft.

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Topics include . . .
- The Three Acts of the Mind
- "The Importance of Propositions"
- Subject versus Predicate
- Kinds of Propositions: Simple versus Compound
- Categorical, Hypothetical, Disjunctive, and Conjunctive Propositions
- "Tricky O Propositions"
- A, I, E, and O Propositions
- Exclusive, Exceptive, and Indesignate Propositions

Amateur Logician Articles to Read. . .

[AmateurLogician]

Someone kindly raised the point that we have to be careful in thinking about the subject and predicate relationship. Some propositions allow us to interchange subject and predicate in a valid way. In immediate inference, we have something known as simple conversion.

Dr. Kreeft’s point, as I take it, is that subject and predicate are not strictly identical nonetheless (unless we have a trivial proposition like X is X). Take, for example, “some men are criminals” can be simply converted to “some criminals are men.” Here we can validly interchange subject and predicate. Yet, even so, subject and predicate are not identical. Surely, moreover, Dr. Kreeft knows about simple conversion --- and he does cover that immediate inference.

[whitb]

The book we used in my practical reasoning course (Philosophy major in college) was "Critical Thinking: The Art of Argument" by Rainbolt and Dwyer. It is an excellent text and you can get it for cheap online. I even managed to get the instructor's edition.

[codework-vber]

@8:30 The letters A, I, O, and E are an homage to (A)-R-(I)-S-T-(O)-T-L-(E)