Proof by intimidation (or argumentum verbosum) is a jocular phrase used mainly in mathematics to refer to a style of presenting a purported mathematical proof by giving an argument loaded with jargon and appeal to obscure results, so that the audience is simply obliged to accept it, lest they have to admit their ignorance and lack of understanding.
The phrase is also used when the author is an authority in their field presenting their proof to people who respect a priori the author's insistence that the proof is valid or when the author claims that their statement is true because it is trivial or because they simply say so. Usage of this phrase is for the most part in good humour, though it also appears in serious criticism.
"Proof by intimidation" is also cited by critics of junk science to describe cases in which scientific evidence is thrown aside in favour of a litany of tragic individual cases presented to the public by articulate advocates who pose as experts in their field.
- Michael H. F. Wilkinson. "Cogno-Intellectualism, Rhetorical Logic, and the Craske-Trump Theorem" (PDF). Annals of Improbable Research. 6 (5): 15–16. Retrieved 2008-02-22.
- Tony Hey (1999). "Richard Feynman and computation" (PDF). Contemporary Physics. 40 (4): 257–265. doi:10.1080/001075199181459. Retrieved 2008-02-22.
- Marjorie K. Jeffcoat (July 2003). "Junk science: Appearances can be deceiving". Journal of the American Dental Association. 134 (7): 802–803. doi:10.14219/jada.archive.2003.0268. PMID 12892436.
- He took umbrage when someone interrupted his lecturing by pointing out some glaring mistake. He became red in the face and raised his voice, often to full shouting range. It was reported that on occasion he had asked the objector to leave the classroom. The expression "proof by intimidation" was coined after Feller's lectures (by Mark Kac). During a Feller lecture, the hearer was made to feel privy to some wondrous secret, one that often vanished by magic as he walked out of the classroom at the end of the period. Like many great teachers, Feller was a bit of a con man. Gian-Carlo Rota (1996). Indiscrete Thoughts. Boston: Birkhäuser. ISBN 0-8176-3866-0.