Throughout the action, Cassius remains relatively unconcerned with the unscrupulous means he is willing to use to further the republican cause, and at Sardis, he and Brutus come almost to breaking up their alliance because Brutus objects to his ways of collecting revenue to support the armies. Cassius sees Brutus as the catalyst that will unite the leading nobles in a conspiracy, and he makes the recruitment of Brutus his first priority. Ironically, his success leads directly to a continuous decline of his own influence within the republican camp.
Clearly, Cassius has his negative aspects. He envies Caesar; he becomes an assassin; and he will consent to bribery, sell commissions, and impose ruinous taxation to raise money. But he also has a certain nobility of mind that is generally recognized. When Caesar tells Antony that Cassius is dangerous, Antony answers, "Fear him not, Caesar; he's not dangerous. / He's a noble Roman and well given." He was no doubt expressing sentiments popular at the time. Cassius is also highly emotional. He displays extreme hatred in his verbal attack on Caesar during Lupercal; he almost loses control because of fear when Popilius reveals that the conspirators' plans have been leaked; he gives vent to anger in his argument with Brutus in the tent at Sardis; he expresses an understanding tolerance of the poet who pleads for him and Brutus to stop their quarrel; and he threatens suicide repeatedly and finally chooses self-inflicted death to humiliating capture by Antony and Octavius. When he becomes a genuine friend of Brutus following the reconciliation in the tent, he remains faithful and refuses to blame Brutus for the dilemma that he encounters at Philippi, even though he has reason to do so.
Of all the leading characters in Julius Caesar, Cassius develops most as the action progresses. At the end of Act I, Scene 2, he is a passionate and devious manipulator striving to use Brutus to gain his ends. By the end of Act IV, Scene 3, he is a calm friend of Brutus who will remain faithful to their friendship until death.
