In Macbeth, Macbeth suffers many conflicting emotions and suffers from an overriding ambition which "o'er leaps itself" (I.vii.27), meaning that he realizes it causes him to make rash decisions in the pursuit of his aspirations. As the witches anticipate Macbeth's new title of Thane of Cawdor and, indeed, go so much further in prophesying his future as king, he, with much encouragement and even coercion from Lady Macbeth, is unable to restrain himself from satisfying those prophesies.
However, he becomes uncertain and overwhelmed by circumstances after seeing Banquo's ghost and so is eager to ensure that, after going to so much trouble to ensure that he is king, there is nothing in his way. He feels that the witches can reassure him. The witches are fully aware of Macbeth's weakness and of his "wicked" nature and intend to take full advantage of him.
The apparitions appear in Act IV, scene i:
- The first apparition is "an Armed Head," which warns Macbeth of Macduff but Macbeth is not afraid of him and can eliminate Macduff easily enough he feels.
- The second apparition is "a Bloody Child," and Macbeth feels empowered when he is told that "none of woman born" (80) can hurt him.
- The third apparition is "a Child Crowned, with a tree in his hand," which tells Macbeth that he will not be defeated "until Great Birnam Wood...shall come against him" (93). That makes Macbeth feel that he is invincible.
There is still a nagging concern for Macbeth about the previous prophecy which stated that Banquo's heirs shall also be kings and so Macbeth presses the witches for more. The witches, reluctantly it seems, reveal:
- "A show of eight Kings, and Banquo last..." which disturbs Macbeth as there is a line of kings, all of whom look like Banquo.
Macbeth does not see this last one as a warning or question his purpose but is resolved to destroy all and any threat to him. He immediately sets out to ensure the death Macduff's entire family, confident that he can overcome any hindrance in his path.
The four apparitions occur in Act 4 when Macbeth seeks out the advice of the witches.
The first apparition is a vision of an armed head that says "Beware Macduff."
The second apparition is a vision of a small child, bloodied that declares that Macbeth cannot be harmed by a man born of woman.
The third apparition reveals itself to be a crowned child holding a tree and says that Macbeth can't come to harm until Birnham Wood reach Dunsinane Hill (where Macbeth lives).
Finally, the fourth apparition indicates that Banquo's descendents will be king afterall. It is a line of eight kings all with the likeness of Banquo and finally Banquo himself leering at Macbeth.
Needless to say the second and third apparitions leave Macbeth feeling pretty confident, and since Macbeth already knew Macduff was a threat, he just dispatches a murderer to Macduff's castle to kill his entire family.
The first apparition is "an Armed Head," which warns Macbeth of danger represented by Macduff. In the next scene, we realize that Macbeth knows Macduff is a serious threat because he has sent murderers to Macduff's castle, and they kill Macduff's wife and children.
The second apparition is "a Bloody Child" that proclaims that "none of woman born shall harm Macbeth." Macbeth is relieved to hear this, thinking he is invincible, and he states:
Then live, Macduff: what need I fear of thee?
But yet I'll make assurance double sure...
Yet, he wants to have Macduff murdered at any rate because he wants to assuage his doubts and fears.
The third apparition is "a child crowned, with a tree in his hand." Macbeth is told that he will not be harmed unless "Great Birnam wood to high Dunsinane hill shall come against him." Macbeth believes that such a sight is impossible because he takes what has been said too literally. He is sure that woods cannot walk, let alone move.
Finally, Macbeth wants to know if Banquo's descendants will inherit the throne one day. So, he sees "a show of Eight Kings, the last with a glass in his hand." They all look like Banquo, and Macbeth is appalled by the sight. He is determined to get rid of anyone who could potentially rob him of his position as the king of Scotland.