Cassius and Brutus are two different type men. Cassius is very critical of Caesar. He ridicules him. He makes light of his epilepsy. Cassius seems more concerned about his own welfare. He is worried about his future. He sees Caesar as a man who can keep him from having any say so whatsoever. Even Caesar is concerned with Cassius' hungry look. In Act One, Scene Two, Caesar confides in Antony, stating that Cassius has a lean, hungry look about him:
Let me have men about me that are fat,
Sleek-headed men, and such as sleep o' nights:
Yond Cassius has a lean and hungry look;(200)
He thinks too much; such men are dangerous.
Caesar is so right. He can read Cassius. Caesar realizes that Cassius is dangerous, claiming that he thinks too much. Indeed, Cassius is the conspirator who persuades Brutus to join the conspiracy. Cassius uses deceit and false petitions to convince Brutus to join the conspiracy. Cassius is not a just and honorable man as Brutus is.
Truly, Brutus is an honorable man. Everything he does is for the good of Rome. He acts out of concern for Rome and its citizens. Brutus is concerned that Caesar has become overly ambitious. For this reason, Brutus joins the conspiracy against Caesar. In Act Three, Scene Two, Brutus admits that he loves Caesar but that he loves Rome more:
If there is anyone in this assembly, any dear friend of Caesar's, to
him I say that Brutus' love to Caesar was no less than his love. If
then that friend demands why Brutus rose against Caesar, this is
my answer,—Not that I loved Caesar less, but that I loved Rome
Brutus is an honorable man. He risked his life for the good of Rome. He fell upon his own sword in death, dying an honorable man. Even Antony declares that Brutus is the most honorable of all the conspirators:
This was the noblest Roman of them all.
All the conspirators, except him,
Did that they did out of jealousy of great Caesar;
Only he, in a general-honest thought
And common good to all, made one of them.
His life was gentle, and the elements
So mixed in him that Nature might stand up
And say to all the world, "This was a man!"
No doubt, there is a major difference between Cassius and Brutus. Cassius was selfish. He was concerned about his own well being. Brutus was concerned for the citizens of Rome, even though they turned against him in the end.