Their inability to come to terms with the facts of their success and the actions they were required to take to achieve it becomes, in many ways, the focus of the film, and becomes the true heart of the story Polanski is trying to tell in this film.
The violence and psychological crumbling it causes is not only accentuated in Polanski's Macbeth by these added scenes, but also in how Polanski presents certain other scenes from the play, as well. These changes have direct implications for the interpretation of the two primary characters in the play, as well as for several of the secondary characters and the overall thrust of the film's story. Perhaps the most significant interpretive choices that Polanski makes in regards to the direct characterizations of Macbeth and Lady Macbeth occur in the staging -- or the filming, rather -- of their soliloquies. Through Polanski's interpretation, these soliloquies become clear instances of the mental deterioration of these characters.
This becomes clear relatively early in the film, beginning with Macbeth's first encounter with a hallucination. Falling in Act Two, scene one of Shakespeare's script, Macbeth delivers a soliloquy in which he believes he sees a spectral dagger floating in front of him, already indicating the guilt he feels over the violence committed, and several of the plays (and film's) most gruesome murders have yet to be committed. Polanski has this dagger appear onscreen as a real and very solid object, effectively making the camera see the world as if through Macbeth's eyes, and again furthering the feeling that his mind is deteriorating (Grossvogel 1972, pp. 49). The fact that the soliloquy is delivered as a voice over -- and inner monologue that the audience hears but does not see Macbeth speak -- creates a disjointedness between what is seen and what is heard that is even more psychologically disconcerting. Macbeth's hallucinations are real, and the audience becomes privy to them at the same time that it receives an inner glimpse into the workings of Macbeth's mind.
The accessibility of the central characters is rendered in a more explicit way by Polanski's decision to have lady Macbeth give her final monologue in the nude. This is not don in a voice over, but rather the actress actually speaks aloud, with what she says surprising the attendant physician and his aide. More surprising to the audience is her nudity, which shows her in an incredibly vulnerable and fragile state. Coupled with the subject of the monologue, which is the extreme guilt that has overtaken her, Polanski again manages to show the internal psychological destruction that is the result of the vicious way in which ambition was pursued.
It has been argued that Lady Macbeth's nudity could simply be the result of a very close reading of Shakespeare's script, which has Lady Macbeth saying, "Put on your nightgown" to herself late in the speech, and that the vision of the dagger presented in the film is merely the most accurate way of rendering the scene given the abilities of cinema as opposed to the stage (Grossvogel 1972). While both of these suggestions definitely have their merits and cannot be wholly discounted, it is unlikely that any choice Polanski made was simply to faithfully render the script -- his overt willingness to adapt it to his own story is readily apparent elsewhere. Instead, these changes are used as ways to show the psychological vulnerability of the characters and the eventual degradation and deterioration of Macbeth's and Lady Macbeth's mental states that takes place as a result of their external actions.
No discussion of Polanski's version of Macbeth can avoid mention of the end of the film, and the marked difference it shows from the end of Shakespeare's play. Shakespeare has his play end with the crowning of Macduff, and the sense that a solid lineage and therefore some semblance of peace has arrived in Scotland. This was not especially historically accurate, though it did serve Shakespeare's political interests at them time by strengthening the validity of King James claims to the Scottish and English thrones, but regardless it brought a certain conclusion to the story that necessarily has effects on its overall interpretation. The same is true, than in a completely opposite way, in Polanski's film.
The decision to end the film not with Macduff's ceremonial crowning, but rather with a scene of Macduff's brother approaching the witches much as Macbeth himself did at the start of the film, is far more ominous than Shakespeare intended. This shows that the cycle of ambition and violence will only continue -- something actually more in keeping with Scottish history than Shakespeare's original ending, and something that serves the themes and plot of Polanski's film version better, as well. Ambition blinds people to consequences, the film suggests, and even though Donalbain has witnessed the fallout of Macbeth's ambition and violence firsthand, and had it hit very close to his own person, he is not dissuaded form his own attempts to achieve power. In this way, the ongoing cycle of human violence and horror is predicted to continue indefinitely, with no real redemption available.
Without ongoing interpretation, the worlds of theatre and of film would be largely stagnant. It is not that there aren't new stories to tell, but even these new stories are essentially re-imaginings of older stories in some form or another. Being conscious and deliberate in one's interpretation and re-imagining of an established work can be the mark of a true genius, and Roman Polanski's 1971 film version of Macbeth is just such a conscious and deliberate artistic act. BY bringing the violence and the psychology of the play to the forefront, Polanski told a new story that had new meanings for his own generation.
Ehses, Hanno. "Representing Macbeth: A Case Study in Visual Rhetoric." Design Issues, Vol. 1, No. 1 (Spring, 1984), pp. 53-63.