Macbeth impresses the audience/reader with an uncertain and unstable state. It is possible to describe the structure of the play as a series of situation exemplifying the conflict between Good and Evil, the story of the fall of a great man. It may even be described as a parable illustrating how man can be gulled by the forces of evil into accepting the appearance as the truth. But structures or themes abstracted from this play would not include the dominant impression left by the play. This impression is not simply the effect of its plot; the quality of the whole tragedy is conveyed by the poetry, which reinforces the situations and their representation on the stage. Poetry succeeds in producing the impression of an equivocal and ambiguous world, where what is seen appears to be different from what is. In fact, the riddling phrases in the very opening scene of the drama are capped with “Fair is foul, and foul is fair”, an image which indicates the moral topsy-turvy in the world of the play. This anticipates the dominant atmosphere of the play, where the entire moral universe tumbles upside down.
Moreover, the internal actions within the minds of the principal characters is most powerfully conveyed through imagery, it is through images and dreams that one penetrates into the deeper recess of the mind, as in Lady Macbeth’s sleep-walking, in Macbeth’s soliloquy, with which the scene vii, Act I starts, and in the scene that follows the murderers of Duncan and Banquo. The intricate and closely-knit pattern of imagery gives the play its remarkable imaginative unity. It establishes the mood of the play, dominated by blood and darkness, and embodies its themes, giving them vivid and concrete expression: the blood coagulates on the murders’ hands, the darkness they summon enters their souls: “Hell is murky.”
The imagery of the play is also the source of much of the dramatic irony—irony that arises when a character is not aware of the real or full significance of his words. The audience sometimes recognizes it at the time, but sometimes it does not emerge until later, when it may also be made clear to the speaker as well. It is particularly common in Macbeth since the general theme of the play is the discovery of by Macbeth and Lady Macbeth of the real significance of their words, thoughts and actions. Individual words and images, often introduced casually, reverberate through the play, sometimes gaining more significance, sometimes changing it –as the meaning of the word ‘done’ is subtly changed to express their realization that they will never escape from their crimes. Lady Macbeth refers cynically to the ruthlessness her husband lacks as an ‘illness’, and the unintentional appropriateness of the term appears later in the actual psychological disorders that afflict them both. This metaphor is an apt expression of the principle that one’s actions are not internal to oneself. This is brought home in simple concrete terms by the association of illness with the two basic requirements for health, sleep and food. Duncan first introduces the metaphor of feasting when he describes the praise of Macbeth’s loyal service as a banquet to him. One major consequence of Macbeth’s treachery is represented symbolically by his isolation from the two actual banquets. This symbol pervades the play, often with ironic effect. Macbeth sees his crime metaphorically as a “poisoned chalice” and his fear that it will be commended to his own lips is realized when it is his act of drinking to Banquo’s health that prompts the entry of the ghost forcing him to confess his guilt. Even the witches’ “hell broth”, their ‘gruel’, is a satanic inversion of the potent symbol of the banquet. Similarly, the terrible images of infancy in Macbeth’s vision of pity and Lady Macbeth’s demonstration of her ruthlessness rise from the cauldron in the form of the Second and Third apparitions, which prove to be heralds of vengeance. The apparition of the crowned child has a tree in his hand, and when Birnam Wood is seen to be advancing in Dunsinane, nature itself seems to be rising against Macbeth. Poetic image and dramatic action are intertwined, giving the play its peculiarly dense imaginative texture.
The image of darkness pervading the play suggest that the light of normal day is forced to give way to the darkness of night or that the darkness has an abnormal obscurity to match the dire deeds committed in it. The images of sickness stress the undermining of the natural state of the human body, while images of outsized clothes suggest that Macbeth has usurped a role that is not natural to him. Such images convey the idea of the unnaturalness of Macbeth’s crime, that it is a convulsion of nature. All these images are facets of Shakespeare’s unifying insight into the nightmare world, which he explores on the stage in Macbeth.