Final answer:
In literature, the existence of ghosts is often left ambiguous, consequently, whether the governess's vision of Miss Jessel's ghost is real or imagined is open to interpretation and characterized by the story's context, psychological underpinnings, and narrative style.
Step-by-step explanation:
The perception of ghosts in literature can often be ambiguous, leaving readers to wonder whether these spectres are real entities within the story's world or manifestations of the characters' minds. Throughout various texts, including Henry James' 'The Turn of the Screw' where the governess sees the apparition of Miss Jessel, this ambiguity is a deliberate technique used by authors to create suspense and invoke questioning of reliability and the supernatural. This question has been a subject of literary debate; some argue that the ghost is a product of psychological instability or intense emotion, while others suggest it may be an actual paranormal occurrence within the story.
In the provided references, the encounters with potential ghosts always underline a degree of uncertainty. Whether it's John's struggle to discern the reality of the noise outside his room, the pedagogue's confrontation with a mysterious horseman, or Jane Withersteen's lioness awakening beside a recovery Fay, the nature of these ghostly experiences remains shrouded in mystery.
Ultimately, the interpretation of whether a ghost in a story is real or imagined is often left to the reader's discretion, guided by context clues within the narrative and various interpretations of the characters' behaviors and the atmosphere crafted by the author.