- Nightmare Retardant/:Narm: Helen Vaughan's final form:
"... or one instance I saw a Form, shaped in dimness before me, which I will not farther describe. But the symbol of this form may be seen in ancient sculptures, and in paintings which survived beneath the lava, too foul to be spoken of... as a horrible and unspeakable shape, neither man nor beast, was changed into human form, there came finally death." note
- Nightmare Fuel: This story managed to given Stephen King nightmares, as he described in the endnotes to his short story collection Just After Sunset.
[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.
- Unfortunate Implications: Some modern readers have criticized "The Great God Pan" for misogyny. 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."
- Values Dissonance: 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.