Teach fish how to swim

Teach fish how to swim is an idiomatic expression derived from the Latin proverb piscem natare doces. The phrase focuses attention on the self-sufficient perception of those who know how to do every thing better than the experts. "It corresponds with the expression, teach your grandmother to suck eggs".^[1] Those who would attempt to do so are thought to exhibit a combination of hubris and arrogance in trying to engage in a needless exercise for which they are ill-equipped.

A corollary idiomatic phrase is part of common usage in Chinese (班门弄斧)^[2]

Origins

Erasmus attributed the origins of the phrase in his Adagia to Diogenianus.^[3]

References

Notes

1. Belton, John Devoe (1891). "A literary manual of foreign quotations, ancient and modern". New York: G. P. Putnam. p. 151. Archived from the original on 21 July 2008. Retrieved 16 April 2014.
2. Muehl, Louis Baker et al. (1999). Trading Cultures in the Classroom: Two American Teachers in China, p. 18, p. 18, at Google Books; 班门弄斧 = display one's slight skill before an expert e.g. 在你面前班门弄斧,太不好意思了 (I'm making a fool of myself trying to show off before an expert like you)
3. Erasmus, Desiderius et al. (1974). Collected Works of Erasmus, p. 134., p. 134, at Google Books; compare Ἰχθὺν νηχέσθαι διδάσκεις

Sources

• Belton, John Devoe. (1891). A Literary Manual of Foreign Quotations, Ancient and Modern, with illustrations from American and English authors and explanatory notes.New York: G.P. Putnam's Sons. OCLC 1440921
• Farrell, Stephen; Paul P. Maglio; and Christopher S. Campbell. (2001). "How to Teach a Fish to Swim," in Visual Languages/Human-Centric Computing Languages and Environments. Piscataway, New Jersey: IEEE Service Center. ISBN 9780780371989; OCLC 248333646