fallacy

Etymology

It is borrowed from Latin fallācia (“deceit, trick, artifice”),^[2][3][4][5] an abstract noun formed from fallāx (“deceptive”) with the suffix -ia,^[2][3][6] from fallō (“to deceive”).^[3][4][7] In post-classical Latin the noun also meant a misleading argument, a sophism (6th century), and an error (12th century).^[2] Its first record, in Caxton (1481), came through Middle Dutch fallacie.^[2] It replaced the earlier Middle English fallace (about 1303, in Mannyng's “Handlyng Synne”),^[4][3][8] from Old French fallace;^[4][3][9] the Anglo-Norman word, meaning falsehood or deceit, is recorded from 1360–79.^[10] Johnson gave both the Latin and the French noun as its source.^[11] The Latin verb is also the source of fail, false and fallible.^[12][4][13]

Earliest recorded meaning

Deception, trickery, a lie: 1481, in Caxton's translation of the History of Reynard the Fox.^[2][4] The older form fallace had the same sense of deceit or a trick.^[9]

Semantic evolution

The sense of deceit, now obsolete, lasted until about 1780.^[2] The logical sense, a misleading argument or a flaw in reasoning, appears in 1532, in Thomas More;^[2] Etymonline dates it to the 1550s.^[3] From 1568 the word named the classical categories of logical fallacy (fallacy of accident and others),^[2] and later, from 1856, beginning with Ruskin, other kinds of error, as in Ruskin's pathetic fallacy.^[2] The sense now most common, a mistaken belief or idea, is recorded from 1590.^[2][7] Johnson (1755) defined it as a sophism, a deceitful argument.^[11]

Timeline

• c. 1303 – fallace, deceit.^[4][3]
• 1481 – deception, trickery, a lie (obsolete by 1780).^[2][4]
• 1532 – a misleading argument; a flaw in reasoning.^[2]
• 1566 – unsoundness of an argument.^[2]
• 1568 – classical categories of logical fallacy.^[2]
• 1590 – a mistaken belief or idea.^[2][7]
• 1856 – other categories of fallacy, in Ruskin.^[2]

Meanings

Noun

1. A mistaken belief or idea, especially one based on faulty reasoning: It is a fallacy that money cures every problem.^[14][6][2]
2. (logic) An error in reasoning that makes an argument invalid; a sophism.^[14][6][2]
3. Unsoundness or faultiness of reasoning.^[14][2]
4. A deceptive appearance; something that misleads the eye or the mind.^[6][14]
5. (obsolete, 1481–1780) Deceit or trickery.^[2][6]

Word family

• fallacious
• genetic fallacy
• pathetic fallacy

Related words

• fail
• fallible
• false

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r s t Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d e f g h Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
5. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
6. ^ a b c d e Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
7. ^ a b c Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
8. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
9. ^ a b Kurath, Hans; Kuhn, Sherman M.; Lewis, Robert E., eds. (1952–2001), Middle English Dictionary, Ann Arbor: University of Michigan Press; online edition ed. Frances McSparran et al. (2000–2018)
10. ^ Anglo-Norman Dictionary (AND2), Aberystwyth University, anglo-norman.net (2nd ed., 2005–)
11. ^ a b Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
12. ^ Ayto, John (2005), Word Origins: The Secret Histories of English Words from A to Z, 2nd ed., London: A & C Black
13. ^ Skeat, Walter W. (1911), A Concise Etymological Dictionary of the English Language, new ed., Oxford: Clarendon Press
14. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins