- idea[idea 词源字典]
- idea:  Etymologically, an idea is the ‘look’ of something – it comes ultimately from the same source as produced the Greek verb ídein ‘see’. Greek idéā itself was used by Plato in the specialized sense ‘archetypal form of something’, which survives in the derived adjective ideal , but as far as the modern English noun is concerned, its sense ‘notion, mental conception’ developed (in Greek) via ‘look, appearance’, ‘image’, and ‘mental image’. Ideology  is a derivative, coined originally in French at the end of the 18th century.
=> ideology, idol[idea etymology, idea origin, 英语词源]
- idea (n.)
- late 14c., "archetype of a thing in the mind of God; Platonic `idea,'" from Latin idea "idea," and in Platonic philosophy "archetype," from Greek idea "ideal prototype," literally "the look of a thing (as opposed to the reality); form; kind, sort, nature," from idein "to see," from PIE *wid-es-ya-, suffixed form of root *weid- "to see" (see vision). Sense of "result of thinking" first recorded 1640s.
Men of one idea, like a hen with one chicken, and that a duckling. [Thoreau, "Walden"]
Idée fixe (1836) is from French, literally "fixed idea."