What are the strengths and weaknesses of Lepidus and Cassius in Julius Caesar?
In Shakespeare's Julius Caesar, it is ironic that in Act I Cassius tells Brutus
Men at some time are masters of their fates:
The fault, dear Brutus, is not in our stars,
But in ourselves, that we are underlings. (1.2.145-147)
For, Cassius is at times master of his fate, and at others is himself superstitious and weak.
In Act I, Scene 2, from which these lines come Cassius persuasively convinces Brutus to join the conspiracy to assassinate Caesar. In Act III after the men have slain Caesar, it is Cassius who recognizes the threat that Marc Antony poses; he advises Brutus to have Antony killed. But, Brutus tells him that they will make a friend of Antony. Wisely, Cassius replies that his doubts always turn out to be justified,
I wish we may. But yet have I a mind
That fears him much; and my misgiving still
Falls shrewdly to the purpose. (3.1.158-160)
Then, when Brutus gives Antony permission to address the Romans after he does, Cassius warns him against doing so: "You know not what you do" (3.1.250), His suspicions of Antony are correct, but he defers to Brutus. Still, he expresses his anxiety,
I know not what may fall; I like it not he defers to Brutus. (3.1.262)
Of course, Marc Antony turns against them and becomes their mortal enemy, fomenting a civil war, and defeating them at Philippi. Even there, Cassius's assessments are correct, for he suggests that his and Brutus's troops to remain at Sardis and force the others to advance so that they will be fatugued and use valuable resources, but Brutus disagrees. As it turns out, Cassius again is correct, although he has acquiesced to Brutus.
But, just before this final battle, Brutus and Cassius quarrel bitterly. Cassius accuses Brutus of wronging him repeatedly, and complains weakly that Brutus no longer loves him:
Hath Cassius lived
To be but mirth and laghter to his Brutus
When grief and blood ill-tempered vexeth him? (4.3.124-126)
just as he has been worried in the first act:
Brutus, I do observe you now of late;
I have not from your eyes that gentleness
And show of love as I was wont to have (1.2.36-38)
Finally, Cassius becomes weakly superstitious. In Act 5 he talks to Messala, telling him that even though he "held Epicurus strong" and has not believed in omens, now he has seen
Two mighty eagles fell, and there they perched,
Gorging and feeding from our soldiers' hands,
Who to Philippi here consorted us.
This morning are they fled away and gone,
And in their steads do ravens, crows, and kites
Fly o'er our heads and downward....
Our army lies, ready to give up the ghost. (5.1.87-93)
In the end, Cassius still has wisdom, but he is fearful and superstitious, and defers to Brutus.
One of the triumvirs after the death of Caesar, Lepidus is considered unworthy to be one of the three rulers of the Roman empire by Marc Antony, while, on the other hand, Octavius is willing to honor him as "a tried and valiant soldier" (4.1.32). At the beginning of Act IV, the triumvirate compile a death list of their political enemies. Lepidus is sent to get Caesar's will so they can reduce some of the legacies in it; when he returns, with a lack of honor, Lepidus consents to allow his brother to die provided Antony will sacrifice his nephew. So, while he may be an excellent soldier, Lepidus lacks loyalty to his family.