A quaint, but still useful term of interest to writers is the expression will o’ the wisp.
The literal sense of will o’ the wisp is “a phosphorescent light that occurs over marshy ground.” It flits about and, according to observers, seems to retreat as one approaches it. The Latin term for this mysterious, elusive light is ignis fatuus [ĭg’nĭs făch’ū-əs], “foolish light.”
The “will” in will o’ the wisp is from a personal name: Will (William) of the wisp (like Jack o’lantern). The “wisp” is a lighted bunch of straw. Various legends have sprung up to explain the phenomenon.
A common story is that a very wicked man (Will or Jack) was so bad that, not only was he rejected by Heaven, the Devil didn’t want him in Hell, but did give him a coal from the eternal flames that he could carry about with him as he wandered the earth.
Because the will o’ the wisp constantly retreats from anyone who tries to catch it, it has acquired the figurative meaning of “something that misleads or deludes; an illusion.”
Here are some uses of the expression in different contexts:
The hunt for the Great American Drama continues. It might be well for some of those who are still in pursuit of this will-o’-the-wisp to pause long enough to discover the Great English Drama, the Great French Drama, the Great Spanish Drama, the Great Italian Drama, or even among the moderns the Great Norwegian or German Drama. –NY TImes, Oct. 14, 1906
Global warming: Chasing a “Will o’ the Wisp” while ignoring a real monster in the sky –headline, BrookesNews.com Aug. 27, 2007
Rather than jettisoning the New Economy in a will-o’-the-wisp search for another magic formula, we ought to treasure what it does well. –LA Times, July 3, 2001
Do you see that absolutely gorgeous creature over there with half the room surrounding them in awe-struck admiration? That is the local “Will-O’-the-Wisp” (WOW) charming the pants off of everyone while delivering almost nothing. (–“The Will-O’-the-Wisp Abnormal Personality”)