Equivocation

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title: "Equivocation" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["verbal-fallacies", "ambiguity"] description: "Misleading use of a term with multiple meanings" topic_path: "general/verbal-fallacies" source: "https://en.wikipedia.org/wiki/Equivocation" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Misleading use of a term with multiple meanings ::

In logic, equivocation ("calling two different things by the same name") is an informal fallacy resulting in the failure to define one's terms, or knowingly and deliberately using words in a different sense than the one the audience will understand.

It is a type of ambiguity that stems from a phrase having two or more distinct meanings, not from the grammar or structure of the sentence.

Fallacy of four terms

Main article: Fallacy of four terms

Equivocation in a syllogism (a chain of reasoning) produces a fallacy of four terms (quaternio terminorum). Below is an example:

: Since only man [human] is rational. : And no woman is a man [male]. : Therefore, no woman is rational.

The first instance of "man" implies the entire human species, while the second implies just those who are male.

Motte-and-bailey fallacy

Main article: Motte-and-bailey fallacy

::figure[src="https://upload.wikimedia.org/wikipedia/commons/9/97/Launceston_Castle_-geograph.org.uk-_22242.jpg" caption="The motte (raised area) and bailey (walled courtyard) defenses at [[Launceston Castle"] ::

Equivocation can also be used to conflate two positions which share similarities, one modest and easy to defend and one much more controversial. The arguer advances the controversial position, but when challenged, they insist that they are only advancing the more modest position.

References

References

1. Damer, T. Edward. (21 February 2008). "Attacking Faulty Reasoning: A Practical Guide to Fallacy-Free Arguments". Cengage Learning.
2. Fischer, D. H.. (June 1970). "Historians' fallacies: toward a logic of historical thought". HarperCollins.
3. Bennett, Bo. (April 2015). "Logically Fallacious: The Ultimate Collection of Over 300 Logical Fallacies". Ebookit.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::