It's a little embarrassing to admit that it has taken me this long to read The Turn of the Screw. I think I first tried to read it four or five years ago, got distracted, and had to return it. Since then, I would frequently remember that I wanted to read it - the title comes up surprisingly often in discussions of other works of fiction - but only now have I actually gone ahead and read it. There's really no excuse for my delay - the whole story is barely under 100 pages long - and I'm glad that I did. It's Henry James, it's 19th century literature, and so it takes a bit more effort to get into the language, but the payoff is quite satisfying.
Turn of the Screw is famous enough that I was already familiar with the outlines of the story. My understanding was that it was a book told from the perspective of a governess who thinks that spirits are tormenting her charges; later, we learn that she has been imagining the spirits, and she herself is the real harm to the children.
I found the actual book to be more ambiguous than that. You could certainly read it as the governess being an unintentional villain, but I think it's also perfectly valid to view her as a heroic victim.
Most of the book seems to come down to the same question that every production of Macbeth must address. In both works, the protagonist can see spiritual objects that nobody else can see. The question is, are they better able to see what is really there than anyone else? Or are they mad? In Macbeth, the director will make the decision. In Turn of the Screw, it's really up to you.
I think there are some very compelling reasons to believe (within the context of the story) that the ghosts are "real." Most specifically, the heroine sees Peter Quint twice (I think) before she learns who he was in life, and learns how he died. I can see her inventing her vision of Miss Jessel, since she has heard of her predecessor and her end, but Peter Quint seems to have arrived ex nihilo. With that as a backdrop, all of her actions seem reasonable, if high-strung: if there are spirits, then they may be affecting the living; the living they are most likely to affect are the young children; the children's occasional lapses can therefore be seen as moving towards or operating under malevolent influence; thus, the governess must do what she can to watch the children, keep them close to her, and prevent activities that take them beyond her protective reach.
Even that initial appearance of Quint, though, can certainly be challenged. What starts this all off is a person who stares at her in a public space. We can imagine a young, inexperienced woman being frightened by this kind of ominous, silent boldness. Suppose, then, that this original man was real, but just a random person, not a ghost. The second visitation, then, could be seen as a "real hallucination," her active mind (big empty house, scary experience, etc.) playing tricks on her. Her actual identification of Peter Quint seems to be suspicious... all that the governess really identifies in the apparition are the red hair, nice clothes, and the fact that he "wasn't a gentleman." That happens to describe Quint, of course, but it really could describe a large number of men in the world. If this is the case, then the whole story becomes a tragedy, with the heroine's initial mistake compounding upon itself, as she interprets every future event to fit within her worldview of an environment filled with hostile spirits.
This latter explanation helps explain some of the stranger conversations in the book. All of the governess's communication with Mrs. Grose are fairly one-sided; you feel like they never really connect or understand one another. There are a couple of times when a chapter ends with the governess observing something, and then the next chapter begins with her describing to Mrs. Grose what occurred; however, her subsequent recollections are more vivid and detailed than the original prose. This initially confused me a little as I read; I thought that the narrator was withholding some of the original event, and then fully describing the scene later on, to maintain some suspense and keep forward momentum in the narrative. It makes more sense, though, that the woman's active mind keeps turning over her imagined scenes, embellishing details and inventing more horrible details.
One final note - I love the way the story ends. It's the opposite of in media res, with an abrupt ending that makes no attempt to describe what happens afterwards. Wonderful, creepy, and perfectly in keeping with the rest of the tale.
I don't often return to the well of my English Lit canon, but I do tend to enjoy my sojourns there. The Turn of the Screw has aged extremely well for a book over a hundred years old, remaining frightening and interesting to this day.