Premises: (1) No man is a donkey. (2) Rahul is a man. Conclusions: (I) Rahul is not a donkey. (II) All men are not Rahul.
Concept/ApproachUse class membership with an E-proposition: if a class ‘‘Men’’ has empty intersection with ‘‘Donkeys’’ and Rahul ∈ Men, then Rahul ∉ Donkeys.Evaluate Conclusion IImmediate application: since Men ∩ Donkeys = ∅ and Rahul ∈ Men ⇒ Rahul ∉ Donkeys. I follows.Evaluate Conclusion II‘‘All men are not Rahul’’ is a vague general statement not derived from the premises; it does not logically follow from (1)–(2). Hence II does not follow.Common pitfallsAccepting statements not grounded in the premises just because they seem generally true.Final AnswerOnly conclusion I follows.
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