Contraposition: Classical Rules, Validity and the Later Convention

Read-only question overview. Answers and scoring remain inside authenticated learner attempts.

• What happens to both terms in the earlier definition?
• Logically, what is “nonanimal”?
• Which two things must be preserved in the earlier form?
• What is the earlier contrapositive of “Every human is an animal”?
• What is the earlier result for a universal affirmative?
• Why can “Some animals are nonhuman” be affirmative?
• Why is no contraposition guaranteed for a particular affirmative?
• In the earlier convention, what does a universal negative yield?
• Which is a proper traditional result from “No human is a horse”?
• What qualification is relevant when inferring a particular from a universal negative?
• Why does “No nonhorse is human” not follow from “No human is a horse”?
• What does a particular negative contrapose to in the earlier scheme?
• What is the proper earlier contraposition of “Some animals are not human”?
• What does the horse witness in the source particular-negative example?
• What distinguishes the later definition?
• What does the later convention derive from “Every human is an animal”?
• What is the quality of “Every nonanimal is nonhuman”?
• What distinguishes simple conversion from contraposition?
• Why is contraposition not the contradictory of a premise?
• What if replacing “some” with “all” makes the result false?
• What is complemented when the predicate is compound?
• What further feature must be respected for modal propositions?
• Which sequence correctly states the earlier four rules?
• If every student is human, what necessarily follows?
• Which follows under the later convention from “Every student is human”?
• What ensures validity for “Some birds are not predatory”?
• What decisively refutes a proposed general contraposition rule?
• “Nonhuman” is a complementary term, not a complete proposition.
• A particular affirmative always contraposes to a particular affirmative in the earlier account.
• The later convention reverses the quality of the original proposition.
• Even with an empty subject class, every universal negative entails a particular negative.