Premise: Bureaucrats marry only intelligent girls (Bureaucrat-spouses ⊆ Intelligent Girls). Fact: Tanya is very intelligent. Conclusions: (I) Tanya will marry a bureaucrat. (II) Tanya will not marry a bureaucrat.
Concept/Approach‘‘Only’’-type statements are one-directional constraints. They restrict who bureaucrats may marry; they do not force every intelligent girl to marry a bureaucrat.Evaluation• Tanya being intelligent satisfies a necessary condition to be eligible as a bureaucrat’s spouse, but it does not make it necessary that she marries a bureaucrat. ⇒ I does not follow.• There is no information forbidding Tanya from marrying a bureaucrat. ⇒ II does not follow.Common pitfallsConfusing ‘‘only A are B’’ with ‘‘all B are A’’; the reverse implication is not warranted.Final AnswerNeither I nor II follows.
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