Etymological fallacy


The etymological fallacy is a genetic fallacy that holds that the present-day meaning of a word or phrase should necessarily be similar to its historical meaning. This is a linguistic misconception, and is sometimes used as a basis for linguistic prescription. An argument constitutes an etymological fallacy if it makes a claim about the present meaning of a word based exclusively on its etymology.
An etymological fallacy may involve looking for the true meaning of words by delving into their etymologies, or claiming that a word should be used in a particular way because it has a particular etymology.

Occurrence and examples

An etymological fallacy becomes possible when a word has changed its meaning over time. Such changes can include a shift in scope or of connotation. In some cases, meanings can also shift completely, so that the etymological meaning has no evident connection to the current meaning.
Ancient Greeks believed that there was a "true meaning" of a word, distinct from a common use. There is evidence that a similar belief existed among ancient Vedic scholars. In modern days, this fallacy can be found in some arguments of language purists.
Not every change in meaning leads to an etymological fallacy, but such changes are frequently the basis of inaccurate arguments.
An example of a word which has greatly changed its meaning is decimation, which originally referred to reduction by a tenth, but now usually means a drastic reduction or complete destruction. Insisting that only the original meaning is "true" constitutes an etymological fallacy.