Having recently seen The Turn of the Screw at The Almeida, I've been thinking about ghosts on stage, and also about literary adaptations. Both these things seem quite problematic to me, although I've always wanted to write a ghost story for the theatre, and I quite like the idea of adapting a novel.
Probably the most famous stage ghost is Hamlet's father, and I'm always fascinated to see how productions handle the battlement scenes. There's one very simple reason why they're so compelling (as well, probably, as lots of complicated ones): the ghost has an agenda, which is as concrete as any living character in the play. When a play's action is grounded in the mechanisms of cause and effect such agendas are pretty essential. After all, most forms of 'realism' depend on a clear relationship between actions and their predicted outcomes. But the 'ghosts' in The Turn of the Screw are quite different. In fact, they may well be pursuing particular devilish aims, but we can never be sure because of the persistent implication that they are figments of the governess' imagination. That isn't a problem in the novella - it's the heart of the story - but on stage...
The distinction between subjective narrative unreliability in prose and dramatic objectivity in realist forms of theatre has quite profound consequences. Indeed, I think it's possible to argue that characters in such plays have no 'meaningful' psychological reality beyond that which is expressed in action. Or to put it another way, there's no point telling me what a character 'really' feels or is 'really' thinking if I never get to understand that myself from what I see in front of me.
The attempt to sustain a purely subjective experience, therefore, seems to me to be beyond the reach of theatrical 'realism'. (I'm just using 'realism' as a short cut here - to pick out stories where the logic of the 'storyworld' can be learned and followed by the reader/audience, even if initially strange.) Yes, we can watch a stage character who sees things in a way we know to be skewed. But only if we can also recognise the reliable reality against which their actions and perceptions can be measured.
Hopping to the issue of adaptation, Salman Rushdie has some interesting things to say. He writes about the need to preserve a work's essential qualities when moving between art forms. If the governess' subjectivity is one of The Turn of the Screw's essential qualities (somewhat complicated by the novella's frame narrative, perhaps) then the question becomes: how can that be preserved in translation? I think 'realist' dramatic forms run into a problem here: the unreliability of her subjective viewpoint can only be preserved if we see the governess juxtaposed with an outside world that throws her beliefs and conclusions into question (for us, the audience). In other words, in order to preserve the subjectivity inherent in (essential to) the novella, we have to introduce an externality that is lacking from the novella. I'm not sure such a contradiction is sustainable. And I wonder if the playwright who wants to explore only the 'locked in' world of a character's subjective viewpoint has to dramatise that through a different, non-realist, dramatic form. I also think it explains why the recent production left me a bit cold. It functioned absolutely fine as a B-movie style chiller. But it lost the essence of the original without finding a true theatrical core to replace it.
(BTW, the photo is a still from The Innocents (1961). How film handles such adaptations is, no doubt, an entirely different question...)