“He was not, as was long believed, a creature of the imagination of the artists, the superstition of the managers, or a product of the absurd and impressionable brains of the young ladies of the ballet, their mothers, the box-keepers, the cloak-room attendants or the concierge. Yes, he existed in flesh and blood, although he assumed the complete appearance of a real phantom; that is to say, a spectral shade.”

In the Prologue, the narrator declares his purpose for writing this book is to expose the truth behind rumors of an Opera Ghost. Although the legends of the phantom are mostly fantasy, a mysterious figure was behind many of the strange incidents. A main theme of the text is superstition versus skepticism, though the story shows that both beliefs can have merit and truth.

“‘Oh, tonight I gave you my soul and I am dead!’ Christine replied. ‘Your soul is a beautiful thing, child,’ replied the grave man's voice, ‘and I thank you. No emperor ever received so fair a gift. The angels wept tonight.’”

Raoul overhears Christine speaking to a mysterious man in her dressing room, and her declarations cause him to become jealous. Erik, the Opera Ghost, appears only as a voice to Christine because he is afraid that she will reject him for his monstrous appearance. This passage displays the power dynamic between Christine and Erik, as Erik gave Christine her miraculous voice in exchange for her soul.

“they had hesitated until the last moment to tell us this curious story, which our skeptical minds were certainly not prepared to entertain. But the announcement of the death of Joseph Buquet had served them as a brutal reminder that, whenever they had disregarded the ghost's wishes, some fantastic or disastrous event had brought them to a sense of their dependence.”

This passage is from the fictional Memoirs of a Manager, in the perspective of the skeptical manager Moncharmin. The managers Poligny and Debienne share that the real reason for their retirement is their constant fear of the ghost’s retaliation for things he doesn’t like. The quotation illustrates the ghost’s power over the managers, as he uses threats of violence to receive his demands.