Equivocation

In logic, equivocation is an informal fallacy involving using a certain word in multiple contexts within an argument. It is a type of ambiguity coming from a phrase with two or more meanings ‒ rather than the grammar of the sentence.

Fallacy of four terms

Equivocation in a syllogism produces a fallacy of four terms. 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 only those who are male.

Motte-and-bailey fallacy


Equivocation can involve equating two similar positions, one modest and easy to defend, and the other more controversial. The arguer then promotes the controversial one, while insisting that they are advancing the more modest one when being criticized.

Footnotes

References



Category:Linguistics
Category:Epistemology
Category:Logical fallacies