Chapter 5. Categorical Propositions. 1. A deductive argument is one that claims to establish its conclusion conclusively. A valid deductive argument is one in which, if all the premises are true, the conclusion must be true .
Universals distribute Subjects.
Negatives distribute Predicates.
If true:AAll men are wicked creatures. If false:
falseENo men are wicked creatures undetermined
trueISome men are wicked creatures. undetermined
falseOSome men are not wicked creatures. true
falseAAll men are wicked creatures undetermined
falseISome men are wicked creatures. true
trueOSome men are not wicked creatures. undetermined
All non-P is non-S is also true.
The relationships among classes in the Boolean interpretation of categorical propositions can be represented in symbolic notation. We represent a class by a circle labeled with the term that designates the class.Thus the class S is diagrammed as shown below: