Definition of "mendacity"

Mendacity is not a uniform offence: it changes its colour according to the nature and substance of the offence to which it is rendered or endeavoured to be rendered subservient. Mendacity, employed in drawing down upon an innocent head the destroying sword of justice, is murder: murder, encompassed with all its correspondent terror. Mendacity, employed in the obtainment of money, is but depredation. Yet, while predatory mendacity is punished with death, the punishment for the murderous mendacity is in comparison but a flea-bite.

1817, Jeremy Bentham, “Swear Not at All. Mat[thew] v. 34.”, in “Swear Not at All:” Containing an Exposure of the Needlessness and Mischievousness, as well as Antichristianity, of the Ceremony of an Oath: [...], London: Sold by R. Hunter, St. Paul's Churchyard, § 14 (Succedanea—True Securities Substitutible to this False One), pages 75–76

[…] Treating the assertion of the witness as the effect, he [Pierre-Simon Laplace] considers as its two possible causes, the veracity or mendacity of the witness on the particular occasion, that is, the truth or falsity of the fact.

1843, John Stuart Mill, “Of the Grounds of Disbelief”, in A System of Logic, Ratiocinative and Inductive, being a Connected View of the Principles of Evidence, and the Methods of Scientific Investigation. […], volume II, London: John W[illiam] Parker, […], § 5, page 196

Big Daddy: […] Think of all the lies I got to put up with!—Pretenses! Ain't that mendacity? Having to pretend stuff you don't think or feel or have any idea of?

1955 March 24 (first performance), Tennessee Williams [pseudonym; Thomas Lanier Williams III], Cat on a Hot Tin Roof, published in Jack Gaver, editor, Critics’ Choice: New York Drama Critics’ Circle Prize Plays 1935–55, New York, N.Y.: Hawthorn Books, 1955, Act II, page 652, column 2

So now the hard Brexiters say, with astonishingly cynical mendacity, that Britain would be better off going it alone.

2017 March 27, “The Observer view on triggering article 50: As Britain hurtles towards the precipice, truth and democracy are in short supply”, in The Observer‎, London, archived from the original on 17 May 2017

A shifty or unreliable politician may hide their mendacity behind deceit, fabrication on confabulation, or by rehearsed counter-attack that simply ignores the questions but makes imputations against the other.

2019 March 23, Jack Waterford, “Prime Minister's ever-diminishing credibility”, in The Canberra Times‎, Canberra

The scandalous bronze-lacker age, of hungry animalisms, spiritual impotencies and mendacities, will have to run its course, till the Pit swallow it.

1858, Thomas Carlyle, “Visit to Dresden”, in History of Friedrich II. of Prussia, Called Frederick the Great. [...] In Four Volumes, volume II, London: Chapman and Hall, 193 Piccadilly, book VI, page 30

Though the rebels had utterly failed in their purposes, having accomplished nothing but the temporary disabling of two lightly armed vessels, and had retreated before the approach of the only formidable vessel there, they formally, and with a mendacity equalled only by some of their own efforts in that direction, proclaimed that they had "driven out of sight, for a time, the entire hostile fleet," and that the blockade of the port of Charleston was raised.

1875, John Howard Hinton, Samuel L[orenzo] Knapp, John O. Choules, William A. Crafts, chapter CXXXIII, in History of the United States of America, from the First Settlement of the Country. By John Howard Hinton, A.M. With Additions by Samuel L. Knapp, Esq., and John O. Choules, D.D. And a Continuation from the Inauguration of President Pierce to the Inauguraion of President Grant. By William A. Crafts, A.M., volume III, Boston, Mass.: Samuel Walker and Company, page 481, column 1

He would have you believe that every error we make is deliberate, that journalists have somehow ginned up a unified conspiracy of lies and mendacities against him.

2018, Jack Shafer, “Donald Trump’s Fake News Mistake”, in Politico