Henry James asserted that the corruptive influence the ‘visitors’, as he described Quint and Miss Jessel, wield over the children in The Turn of the Screw was intended to inspire ‘a vision of evil’. He shrouded this phrase in ambiguity quite on purpose, believing that this haunting vision would have the greatest impact if it were left solely to the reader to construct within his or her own imagination. The vision haunted Britten and librettist Myfanwy Piper in a somewhat different way in the course of their 1954 adaptation of the story, prompting consideration of what form the evil should take and how it could be presented on stage. With the decision to incorporate James's elusive ghosts into the cast they invested the vision with movement and speech (see J. P. E. Harper-Scott for further discussion of the implications of ‘realising’ the ghosts in Chapter 16). The question of how successfully Piper realised James's conception of the supernatural was one that she would ponder long after the opera's premiere. The ‘vision’, she concluded, would always be subjective and her task was to instil a notion of the danger and tragedy of something that was beyond understanding. Part of the opera's success would rely on acquainting a mid-twentieth-century audience with the allure of the ghost story that flourished in James's time. His readership regarded the supernatural, whether in fiction or in everyday life, as ‘both fearful and terrible and ardently desired; it was a spooky sense that there was more to the world than the everyday, and an intimation that reality might be transfigured by something above and beyond.’ Bly's ghosts had enthralled Britten since his late teens, but his interest in what James termed the ‘vision of evil’ extended further.
Supernatural poetry and prose could also denounce conflict. It contained subject matter that appealed to the composer's own fervent pacifistic convictions. The vision could accentuate the horror of revolution (seen in the setting of Wordsworth's nightmarish vision of massacre in Nocturne, 1958) or meaningless slaughter (described by the ghosts of dead soldiers in Wilfred Owen's poetry in War Requiem, 1962), where both the realism of battle and its inevitable aftermath are evoked.