reductio ad absurdum

Noun

reductio ad absurdum (usually uncountable, plural reductio ad absurdums)

1. (usually) The method of disproving a statement by assuming the statement is true and, with that assumption, arriving at a blatant contradiction.
   • “You, gentlemen, as representatives of that institution which recognizes only truths that are deduced from reductio ad absurdums will probably have no difficulty in perceiving the truth of this absurdity and hence be ready to excuse the outcome of it—my absence.”1894, Flora Helm, “Concerns a Talk in Which Anarchy and Love Are Blended”, in Between Two Forces: A Record of a Theory and a Passion, Boston, Mass.: Arena Publishing Company. […], pages 149–150
   • Constructing representations out of atoms that are already themselves representations cannot address the origins of the atoms per se. Careful pursuit of such approaches has yielded bizarre reductio ad absurdums such as the implication that virtually all concepts that human beings are capable of...1998, Mark H. Bickhard, “Constructivisms and Relativisms: A Shopper’s Guide”, in Michael R[obert] Matthews, editor, Constructivism in Science Education: A Philosophical Examination, Dordrecht...

   Synonyms:

   apagoge, proof by contradiction, reduction to the absurd