Invincible ignorance fallacy
The invincible ignorance fallacy,[1] also known as argument by pigheadedness,[2] is a deductive fallacy of circularity where the person in question simply refuses to believe the argument, ignoring any evidence given.It is not so much a fallacious tactic in argument as it is a refusal to argue in the proper sense of the word.The first Pope to use the term officially seems to have been Pope Pius IX in the allocution Singulari Quadam (9 December 1854) and the encyclicals Singulari Quidem (17 March 1856) and Quanto Conficiamur Moerore (10 August 1863).Aquinas, for instance, uses it in his Summa Theologica (written 1265–1274),[3] and discussion of the concept can be found as far back as Origen (3rd century).When and how the term was taken by logicians to refer to the very different state of persons who deliberately refuse to attend to evidence remains unclear, but one of its first uses was in the book Fallacy: The Counterfeit of Argument by W. Ward Fearnside and William B. Holther[4] in 1959.