Universal Propositions

The Universal Affirmative

Examples:
  1. All politicians are liars.
  2. All men are mortal.
  3. All good Web pages are written in html.
  4. All good men come to the aid of their party.
  5. All men have what it takes to become a successful salesman.
The universal affirmative states that all members of a particular class belong to another class. In set theory, we might say that the universal affirmative tells us that one set of objects is a subset of the other set. Here are some important things to know about the universal affirmative:

The Universal Negative

Examples:
  1. No politician is intelligent.
  2. No man is immortal.
  3. No good Web pages contain Java or browser-specific tags.
  4. No good men will betray their principles.
  5. No men have what it takes to be a successful mother.
The universal negative states that no member of a class is a member of another specified class. In set theory, this corresponds to saying that two sets are “disjoint”, or saying that the intersection of the two sets is the null set. Here are some important things to know about the universal negative:
I want to go back to the Aristotelian Propositions.

I want to check out the particular propositions.

I think I have the hang of it. I want to see how these fit together into a syllogism.

Take me back to the History of Logic homepage.


Jason Corley -- corleyj@cobweb.scarymonsters.net