- a deceptive, misleading, or false notion, belief, etc.: That the world is flat was at one time a popular fallacy.
- a misleading or unsound argument.
- deceptive, misleading, or false nature; erroneousness.
- Logic. any of various types of erroneous reasoning that render arguments logically unsound.
- Obsolete. deception.
Origin of fallacy
SynonymsSee more synonyms on Thesaurus.com
Examples from the Web for fallacies
These are the facts to rebut just a few of the fallacies I read on a daily basis about our party.The Truth About Yisrael Beytenu
November 9, 2012
Masood Aziz outlines six fallacies they perpetuate about the US engagement in Afghanistan.Don't Listen to Experts on Afghanistan
May 28, 2010
But this post-partisan dream, it turns out, rested on two fallacies.Obama Gets His Mojo Back
March 11, 2010
Perhaps Bentham's Book of Fallacies is too political for me to commend it to you here.Critical Miscellanies (Vol. 3 of 3)
It also helps to guard us against some fallacies by showing the consequences which flow from them.Parmenides
In the 'Innocents' he laughs at delusions and fallacies—and enjoys them.Mark Twain, A Biography, 1835-1910, Complete
Albert Bigelow Paine
“That is one of the most popular of fallacies,” she answered me crushingly.The Love Affairs of an Old Maid
Science has been built upon concurrence: so have been most of the fallacies and fanaticisms.The Book of the Damned
- an incorrect or misleading notion or opinion based on inaccurate facts or invalid reasoning
- unsound or invalid reasoning
- the tendency to mislead
- logic an error in reasoning that renders an argument logically invalid
Word Origin and History for fallacies
late 15c., "deception, false statement," from Latin fallacia "deception," noun of quality from fallax (genitive fallacis) "deceptive," from fallere "deceive" (see fail (v.)). Specific sense in logic dates from 1550s. An earlier form was fallace (c.1300), from Old French fallace.
A false or mistaken idea based on faulty knowledge or reasoning. For example, kings who have divorced their wives for failing to produce a son have held to the fallacy that a mother determines the sex of a child, when actually the father does. (See sex chromosomes.)