Reduction

To maintain human authorship, one must accept that: an unlettered merchant suddenly mastered Arabic at its peak, independently discovered historical facts verifiable only centuries later, accurately described natural phenomena unknown in his time, and created a text that transformed civilizations and remains linguistically unmatched. Each claim strains credibility; together they break it.

This is reductio ad absurdum applied historically: the natural explanation requires accepting too many improbabilities simultaneously.