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existential fallacy

Drawing a "some" conclusion from premises that are all "all" or "no" statements.

On the Boolean reading, a syllogism commits the existential fallacy when both premises are universal and the conclusion is particular. Universal premises don't say anything exists, so they can't guarantee a conclusion that does.

Examples

  • "All unicorns are horses. All horses are animals. So some unicorns are animals."

See also

existential import Boolean interpretation
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