reductio ad absurdum

 
Pronunciation: /rɪˌdʌktɪəʊ ad abˈsəːdəm/

noun

Philosophy
  • a method of proving the falsity of a premise by showing that its logical consequence is absurd or contradictory: the argument is a reductio ad absurdum of utilitarianism

Origin:

Latin, literally 'reduction to the absurd'