fallacy

American  

[fal-uh-see] / ˈfæl ə si /

noun

plural

fallacies

1. a deceptive, misleading, or false notion, belief, etc..

   That the world is flat was at one time a popular fallacy.

   Synonyms:

   misapprehension, delusion, misconception

2. a misleading or unsound argument.

3. deceptive, misleading, or false nature; erroneousness.

4. Logic. any of various types of erroneous reasoning that render arguments logically unsound.

5. Obsolete. deception.

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fallacy British  

/ ˈfæləsɪ /

noun

1. an incorrect or misleading notion or opinion based on inaccurate facts or invalid reasoning

2. unsound or invalid reasoning

3. the tendency to mislead

4. logic an error in reasoning that renders an argument logically invalid

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fallacy Cultural  

1. 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.)

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Etymology

Origin of fallacy

First recorded in 1350–1400; from Latin fallācia “a trick, deceit,” from fallāc- (stem of fallāx ) “deceitful” + -ia -y ³; replacing Middle English fallace, from Middle French

Explanation

A fallacy is a misleading argument or belief based on a falsehood. If you oppose state testing in schools, you think it is a fallacy that educational quality can be measured by standardized tests. Fallacy comes from the Latin fallacia, for deceit. It technically means a flaw in an argument that makes it deceptive or misleading. In poetry, the "pathetic fallacy" is the false idea that things like rocks or stars have human feelings (pathos). Fallacy can also be used more generally for any false statement or idea. Some synonyms are misconception and error.

Example Sentences

Fallacy or whatever, but it's traditionally called the Netherlands Fallacy.

From Salon • May 3, 2024

Fallacy 4: Schulz fails to grasp the transformation of college spots.

From Seattle Times • Aug. 18, 2023

Fallacy of unwarranted assumption a general category of informal fallacies in which an arguer implicitly or explicitly relies on reasons that require further justification.

From Textbooks • Jun. 15, 2022

Earlier this week, following a rash of accusations against CBS chief Les Moonves, the Atlantic writer Megan Garber called this the Familiarity Fallacy.

From Washington Post • Aug. 2, 2018

The excessive use of this expedient is deplored by John Ruskin in a chapter of "Modern Painters" entitled "The Pathetic Fallacy."

From Materials and Methods of Fiction With an Introduction by Brander Matthews by Hamilton, Clayton Meeker

Related Words

• deception
• falsehood
• heresy
• inconsistency
• misinterpretation
• paradox
• untruth