Qiyās al-Khalf: Compound Reductio, Impossibility and Proof of the Claim

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

• What is the main purpose of qiyās al-khalf?
• How many syllogisms underlie qiyās al-khalf in the text?
• What form does the first syllogism in reductio take?
• What is the main form of the second syllogism?
• Which is the correct contradictory of “Every human is an animal”?
• What properly counts as the “impossible” in a reductio?
• If P entails Q and Q is false, what follows?
• How should “If P then Q; Q; therefore P” be evaluated?
• What is the appropriate conclusion of the first syllogism?
• What must be assumed initially?
• What distinguishes lacking proof from denying a proposition?
• What allows two hypothetical conditionals to be chained?
• What are the quantity and quality of “kull insān ḥayawān”?
• What does a particular negative assert?
• Which impossibility is invoked to affirm the claim?
• What is missing if someone calls the consequence merely “strange”?
• Which earlier topic is essential to reductio?
• Which contradicts “Every square has four sides”?
• Why is the denial of “Every intelligent student finishes first” not absurd?
• If the first stage entails an impossibility, what does the second stage reject?
• What does the first syllogism supply to the second?
• When does “the contradictory is false, therefore the claim is true” follow?
• Which sequence correctly describes the two stages?
• Is stating “If the contradictory holds, absurdity follows” sufficient?
• What is the next new section after qiyās al-khalf?
• Which is the contradictory of “Some birds fly”?
• Qiyās al-khalf begins by assuming the contradictory of the claim.
• The contradictory of a universal affirmative is a universal negative.
• In a conditional syllogism, denying the consequent validly denies the antecedent.
• A surprising consequence is automatically impossible in logic.