Macbeth and Lady Macbeth are most like Brutus and Cassius in Julius Caesar. Cassius plays a role similar to that of Lady Macbeth. Like her, Cassius cannot carry out his plan on his own. She is incapable of murdering Duncan; she needs to persuade her husband to do it. Cassius is incapable to forming a sufficiently strong conspiracy to assassinate Caesar; he desperately needs Brutus to take the lead. Both Macbeth and Brutus have misgivings about killing their proposed victims, and both engage in soliloquies in which they argue with themselves about going through with the murders. Macbeth says of Duncan that he has been a good king and that
Will plead like angels trumpet-tongued against
The deep damnation of his taking-off,
And pity, like a naked new-born babe,
Striding the blast, or heaven's cherubin horsed
Upon the sightless couriers of the air,
Shall blow the horrid deed in every eye,
That tears shall drown the wind. (Act 1, Scene 7)
Brutus thinks more logically and rationally than Macbeth, but Brutus is reluctant to help Kill Caesar because the man is his good friend. It seems vile and treacherous to kill such a friend who sincerely loves him. The most pathetic part of the assassination occurs when Caesar says, "Et tu, Brute?"
It must be by his death, and, for my part,(10)
I know no personal cause to spurn at him,
But for the general. (Act 2, Scene 1)
In both cases, it seems obvious that Macbeth and Brutus would not have gone through with their bloody deeds if it had not been for the persuasive and manipulative powers of Lady Macbeth and Cassius, respectively. Shakespeare's apparent purpose in setting up the plot this way was to preserve some audience sympathy for his two heroes, Macbeth and Brutus. They are cajoled and tricked into doing what they did. Lady Macbeth and Cassius are relatively weak characters. They need someone else to do their dirty work. They are both unscrupulous; they will say anything and do anything to get the two really strong and noble men to do what they want. Macbeth, as we know from the outcome of the play, should never have listened to his wife. Brutus, as we know from Shakespeare and from history, should probably never have listened to Cassius, a selfish, inferior, and unlikable man.
I think that Julius Caesar and Duncan are a lot alike. On a literal level, both of those characters are powerful rulers. Duncan is the King of Scotland, and Caesar is the ruler of the Roman Empire. Both Caesar and Duncan are well liked by the people that they rule over. Macbeth even convinces himself not to kill Duncan because he is such a well liked and revered ruler. Casca, from "Julius Caesar" points out the following:
"If the tag-rag people did not
clap him and hiss him, according as he pleased and
displeased them, as they use to do the players in
the theatre, I am no true man."
The quote shows how much the common people adore Caesar. They liken him to a famous and well liked actor.
I also see the similarity in Duncan's and Caesar's fates. Both men are plotted against by people wanting to take over their powerful position. Both men are plotted against by men they considered friends. Duncan was a guest in Macbeth's castle. Caesar and Brutus are also friends. Both men are killed by that friend.
Both Duncan's death and Caesar's death trigger a domino effect of more violence.