* NightmareFuel: This story managed to given Creator/StephenKing nightmares, as he described in the endnotes to his short story collection ''Literature/JustAfterSunset''.
-->[''The Great God Pan''] surmounts its rather clumsy prose and works its way relentlessly into the reader's terror-zone. How many sleepless nights has it caused? God knows, but a few of them were mine. I think 'Pan' is as close as the horror genre comes to a great white whale.
* ValuesDissonance: Raymond's justification for using Mary as a test subject goes completely unchallenged:
-->As you know, I rescued Mary from the gutter, and from almost certain starvation, when she was a child; I think her life is mine, to use as I see fit.
* TheWoobie: Poor Mary and Trevor.
* UnfortunateImplications: Some modern readers have criticized "The Great God Pan" for misogyny.[[http://weirdgenesis.blogspot.com/2013/05/the-great-god-pan-1890-by-arthur-machen.html]][[http://somanybooksblog.com/2012/10/31/the-great-god-pan/]][[http://ttapress.com/1030/on-machen-misogyny-and-mad-women-in-attics/]][[http://www.blackgate.com/2012/10/30/arthur-machen-and-the-great-god-pan/]] ''The Encyclopedia of Science Fiction'' (1993) is widely quoted as stating that "The story begins with an sf rationale (brain surgery) which remains one of the most dramatically horrible and misogynistic in fiction."[[http://en.wikipedia.org/wiki/The_Great_God_Pan#Critical_opinion]]