Almost every character in this play wants something. The most ambitious characters are, in order of appearance, the witches, Macbeth, Malcolm, and Lady Macbeth.
The witches are the ones who make the prophecies and share them with Macbeth. They are highly ambitious, because they decide to alter the course of the entire kingdom by getting inside Macbeth’s head and making him their puppet. The plan is a complex one, involving prophecies for Macbeth related to his becoming king that will spur him into action. Before the witches get involved, Macbeth is by all accounts a perfectly brave and honorable solider.
The witches tell Macbeth three prophecies. The first two relate directly to him. (First, they refer to him by his current title.)
All hail, Macbeth! hail to thee, thane of Glamis!
All hail, Macbeth, hail to thee, thane of Cawdor!
All hail, Macbeth, thou shalt be king hereafter! (Act 1, Scene 3)
The third prophecy relates to Banquo, Macbeth’s friend and fellow soldier. The prophecy says that Banquo’s sons, not Macbeth’s, will be king. This prophecy will cause trouble for Banquo later, because Macbeth does not want competition.
When Duncan names his son, Malcolm, as king instead of Macbeth, he is not pleased. His ambition has been piqued.
The Prince of Cumberland! that is a step
On which I must fall down, or else o'erleap,
For in my way it lies. Stars, hide your fires;
Let not light see my black and deep desires (Act 1, Scene 4)
He may not have been interested in being king before, but now it is all he wants. He has been told he will be king, so he wants to be king!
The witches are not satisfied with just getting the ball rolling. They will return to make more prophecies when Macbeth starts to falter, warning him to beware Macduff (who aids the King’s son Malcolm in fighting Macbeth), and that no man born of woman can hurt him. They can’t seem to keep out of the action. Their ambition makes them want to be involved, and want to keep their guy winning as long as possible, or at least just manipulate him.
Naturally, Macbeth seems to be the most ambitious character in the play. After all, he is the one with the most blood on his hands. Once prompted to action, he is like a snowball rolling downhill. He gets bigger and bigger and can’t seem to help himself.
However, Macbeth is not as easy to prompt as you may think. The witches do not quite do the job. They light the flame, but can’t quite keep it going. Macbeth does write to his wife, Lady Macbeth, and she is ambitious too. (More about her later.) Needless to say, once Macbeth is on a roll, he seems to turn into a spree killer.
Macbeth struggles at first with the concept of killing Duncan, because Duncan is actually his kinsman and has done nothing to deserve it except be king, and Macbeth wants to be king. In a soliloquy, Macbeth admits to himself that he has no reason to kill Duncan except his ambition.
I have no spur
To prick the sides of my intent, but only
Vaulting ambition, which o'erleaps itself
And falls on the other. (Act 1, Scene 7)
He does kill Duncan, and it does not stop there. Once he does, he is faced with the fear that he can’t hang on to this kingdom. He worries that Banquo, for instance, might suspect him. Banquo does. He says in a soliloquy addressed to Macbeth “Thou hast it now…I fear,/ Thou play'dst most foully for't” (Act 3, Scene 1). In other words, he is worried that Macbeth got to be king by killing the king.
Macbeth kills Banquo, his friend (and tries to kill his son) out of ambition to maintain his throne now that he has it. He also sends murderers to kill Macduff, and they end up killing his wife and son. Ambition has turned Macbeth into a serial killer.
As the play goes on, we start to hear more descriptions of Macbeth as the bloody tyrant. Any resemblance of him to the hero he was in the beginning of the play is gone. By the fourth act, the witches are giving him more prophecies to prepare for war, and he is getting more and more deranged as he prepares to go to battle against Malcolm, the rightful heir to the throne. Macbeth commits a version of suicide in the end, losing his will to fight when he realizes that everyone has turned against him.
The king’s son, Malcolm was the one who was supposed to take Duncan’s place when he died of, hopefully, natural causes. No one thought the death would be quite so imminent. Malcolm was young, but brave, clever, and a natural leader. His brother Donalbain fled to Ireland, where he did not seem to accomplish anything. Macbeth uses the fact that they flee to put suspicion on them.
Malcolm is not idle in England. He is planning to take back his kingdom by raising an army to take out Macbeth. The first thing he does is have a conversation with Macduff, to see if he is loyal. It is an interesting conversation. Malcolm has a problem. He was chosen as heir, but that is almost his only advantage. How can he get people to trust him? Who can he trust? So he decides to tempt Macduff, to see which side he is on.
I am young;
You may deserve of him through me, and wisdom
To offer up a weak poor innocent lamb
To appease an angry god. (Act 4, Scene 3)
Macduff assures Malcolm that he is not treacherous, and he will follow Malcolm despite his youth and, presumably, inexperience.
Now with an army, Malcolm goes after Macbeth. He uses some clever tricks, including pretending his soldiers are a moving forest (thus making one of the witches’ prophecies come true “Great Birnam wood to high Dunsinane hill/Shall come against him” (Act 4, Scene 1). In the end, Malcolm is successful. Macduff is able to kill Macbeth (because he was not born of woman after all, since he was ripped from his mother’s womb). The war is over.
One of the most tragic characters in the play, Lady Macbeth is a cautionary tale in ambition. Macbeth writes her a letter telling her of the witches’ prophecies, and she seems to take to the idea right away. The fact that he is not chosen as heir is a tiny detail. Just kill the king! She is not phased. When he gets second thoughts, she questions his masculinity.
When you durst do it, then you were a man;
And, to be more than what you were, you would
Be so much more the man. (Act 1, Scene 7)
He gets the idea. However, she knows her husband well. Even before he came home she knew he would have a hard time doing what she thought had to be done. She even goes so far as to ask to become a man, so she could do it herself.
Come, you spirits
That tend on mortal thoughts, unsex me here,
And fill me from the crown to the toe topfull
Of direst cruelty! (Act 1, Scene 5)
That is ambition! My cowardly husband can’t do it, so make me a man so I can do it myself. Lady Macbeth plays a stereotypical meddling wife, in some ways. She tells Macbeth exactly what to do, right down to scolding him when he doesn’t follow her directions (“Why did you bring these daggers from the place?” (Act 2, Scene 2). Yet she also acts as cheerleader (“We fail!/But screw your courage to the stickingplace, /And we'll not fail. (Act 1, Scene 7), because she does not seem to want to be the one to do the actual stabbing herself. That seems to be the man’s job.
Lady Macbeth’s ambition gets the best of her. When she sees Duncan, she imagines that he looks like her father as he sleeps. This little bit of humanity haunts her. She sees the blood on her hands from the daggers she removes from the scene. For the rest of the play, which isn’t very long, she is not herself. Eventually, she can’t take it any longer. She snaps, and kills herself, unable to imagine herself without the blood on her hands.
This is a play about the dangers of succumbing to our baser natures. We all have ambitions, but we do not always accomplish our goals by any means necessary. Some of the characters in this play use trickery and murder to get what they want, and the result is disaster. Macbeth and Lady Macbeth both killed themselves in one way or another. The consequences of ambition are tragic when you use any methods to achieve it.