Prophecy
The plot of Macbeth is set in motion ostensibly by the prophecy of the three witches. The prophecy fans the flames of ambition within Macbeth and Lady Macbeth, serving as the primary impetus for the couple to plot the death of Duncan--and subsequently Banquo. But one also wonders: Would Macbeth have committed such heinous crimes if not for the prophecy? What if he had ignored the witches’ statements? Such speculation, however interesting, ultimately appears futile, since the prophecy itself is self-fulfilling. The witches know Macbeth’s tragic flaw: given the irresistible temptation to become King, he will choose to commit murder even though he could simply discard their words. As it turns out, the prophecies are not only fated but fatal, as Macbeth's confidence in the witches leads him to fight a rash battle in the final act.
Guilt and Remorse
Some of the most famous and poetic lines from Macbeth are expressions of remorse. “Will all great Neptune’s ocean wash this blood / Clean from my hand?” exclaims Macbeth after he stabs Duncan (II ii 58-59). Similarly, Lady Macbeth is plagued by a “spot” that she cannot remove from her hand: “Out, damned spot! Out, I say. . . What, will these hands ne’er be clean?” (V I 30-37). At first physical remainders of a regrettable crime, the royal blood leaves permanent marks on the psyche of the couple, forever staining them with guilt and remorse. The different ways in which the Macbeths cope with their crimes show how their characters develop: whereas Lady Macbeth is initially the one without scruples, urging Macbeth to take action, it is an overpowering sense of guilt and remorse that drives the Lady to her untimely death. Macbeth, on the other hand, seems to overcome the guilt that plagues him early on in the play.
Ghosts and Visions
Just as an overwhelming guilty conscience drives Lady Macbeth mad, so too does Macbeth’s “heat-oppressed” brain project the vision of a dagger before he murders Duncan (II i 39). In what concerns ghosts and visions, the relation of the natural to the supernatural in Macbeth is unclear. The three apparitions that the witches summon, for example, are usually taken to be “real”—even if only as supernatural occurrences. But the matter is less clear when it comes to Banquo’ ghost. Macbeth is the only one who sees the ghost in a crowded room; is this yet another projection of his feverish mind? Or is it really, so to speak, a supernatural occurrence? Such ambiguities contribute to the eerie mood and sense of uncanniness that pervade the play, from the very opening scene with the three bearded witches.
The Natural/Supernatural
If the witches’ prophecy is understood to be imposing a supernatural order on the natural order of things, the natural order can also be understood as responding with tempestuous signs. Following Duncan’s death, Lennox describes the “unruly” night in some detail. Similarly, Ross notes that “the heavens, as troubled with man’s act, / Threatens his bloody stage” (II iv 5-6). In the same scene, the Old Man and Ross both agree that they saw horses eat each other. Even the events leading to the conclusion of the play can be understood as a negotiation of the natural and supernatural. Whereas Macbeth believes that he will live the “lease of nature”—since Birnam Wood cannot possible come to Dunsinane Hill—the forest is literally uprooted by the English army in accordance with the prophecy. The dichotomy between the natural and the supernatural forms a backdrop that suggests the epic proportions of the struggle over the Scottish crown.
Dichotomy and Equivocation
“Fair is foul, and foul is fair / Hover through the fog and filthy air” (I i 10-11). The first scene of the first act ends with these words of the witches, which Macbeth echoes in his first line: “So foul and fair a day I have not seen” (I iii 36). In a similar fashion, many scenes conclude with lines of dichotomy or equivocation: “Hear it not, Duncan; for it is a knell / That summons thee to heaven or hell” (II i64); “God’s benison go with you, and with those/ That would make good of bad, and friends of foes” (II iv 41-42). Such lines evoke an air of deep uncertainty: while polarities are reversed and established values are overturned, it is entirely unclear as to whether the dichotomous clarity of “heaven or hell” trumps the equivocatory fogginess of “fair is foul, and foul is fair.” Thus, for Macbeth, this translates into an uncertainty as to whether the prophecies are believable. It seems that Birnam Wood will either come to Dunsinane Hill (a supernatural event) or it will not (a natural event); but the actual even turns out to be neither here nor there, as the Wood figuratively comes to Dunsinane.
Ambition and Temptation
Ambition and temptation both play a key factor in Macbeth and Lady Macbeth’s decision to kill Duncan. Macbeth possesses enough self-awareness to realize the dangers of overzealous ambition: “I have no spur / To prick the sides of my intent, but only / Vaulting ambition which o’erleaps itself / And falls on th’other” (25-28). And yet, the temptation to carry out the witches' prophecy is ultimately too strong for Macbeth to curb his ambition. In Lady Macbeth’s lexicon, incidentally, “hope” is also another word for “ambition” and perhaps “temptation.” As Macbeth expresses his doubts about killing Duncan, she demands: “Was the hope drunk / Wherein you dressed yourself” (35-36)? Ironically, Lady Macbeth must herself rely on intoxicants to “make [her] bold” before executing her ambitious and murderous plans (II ii 1). Once the intoxication wears off, Lady Macbeth finds that she is unable to cope with the consequences of her own "hope." Ultimately, ambition and temptation prove fatal for both the Macbeths.
Salvation and Damnation
As a morality tale of sorts, Macbeth has as its near contemporary Christopher Marlowe’s Dr. Faustus. Like Dr. Faustus, Macbeth recognizes the damning consequences of his crime:
. . . Besides, this Duncan
Hath borne his faculties so meek, hath been
So clear in his great office, that his virtues
Will plead like angels, trumpet-tongued against
The deep damnation of his taking-off.” (I vii 16-20)
And yet Macbeth carries out the crime, thus precipitating his own descent into hell. Later in the play, appropriately, Macduff calls Macbeth by the name of “hell-hound” (V x 3). Indeed, the story of Macbeth is that of a man who acquiesces in his damnation—in part because he cannot utter words that may attenuate his crime. As Duncan’s guards pray “God bless us” on their deathbed, Macbeth cannot say one “Amen” (II ii 26-27). His fate is thus sealed entirely by his own hands.