Macbeth ~ Act IV & V

In these two acts, the downhill swoop of the play, the fatal parts of the action, Macbeth starts by going back to the witches. Since seeing Banquo's ghost he is frightened and wants to know his future. He is frustrated by them: "though you untie the winds and let them fight against churches, though the yesty waves confound and swallow .... answer me to what I ask you," and though they persist he leaves them knowing that Macduff is a threat, no woman born man can kill him, and that until the forest around his castle comes to his door he will be safe.
This information gives him a sense of pride and resolution, but still he wants to make sure he is okay, so he hires some more murderers and kills Macduff's family while he is away in England. Macbeth has truly become a tyrant in Scotland. We find in the last act, the soldiers say, "he's made; others, that less hate him, do call it valiant fury; but for certain he cannot buckle his distempered cause within the belt of rule." He's gone about murdering dissenters, ignoring everything rational and/or good in his self-absorbed fury, greed, and guilt.
His actions are not ignored though, and Macduff, Malcom, and some other Scottish ex-patriots in England decide to take action along with the English army and get Macbeth out of office. Macbeth, on hearing the news is not afraid with the knowledge that the witches gave him, but he is punished for assuming and dies under the hand of Macduff (a c-section baby). Malcom becomes king, the rightful heir in the first place, and we trust he will be better than the last.
At the end, the story of Banquo's royal progeny goes unresolved but we are led to believe that it will be so someday, because the witches, no matter how cleverly put or complexly assembled, say the truth.
In Macbeth, there is lots of evidence of moral. When Macduff's wife is questioning her assending murder: "I have done no harm. but I remember now I am in this earthly world, where to do harm is often laudable, to do good sometime accounded dangerous folly" which follows the "fair is foul, foul is fair" theme that the witches presented at the beginning of the play. Her conversation with her son about traitors, also, s almost Socratic! The doctor in Act V condemming Lady Macbeth's illness not of the physic but it is "the heart [that] is sorely charged." There is abig lesson of guilt in Macbeth. Both personal guilt and also basic human guilt, for communal deeds done. Often in this play, the good felt guilty for knowing secrets they shouldn't (like Banquo) and were depressed by the facts that should have been reversed. Of course the guilty were guilty too, but it was not kept to them; it affected everybody.