In Act 1 Scene 2 we see Cassius manipulating Brutus. Cassius’ immediate concern is to convince Brutus to join the conspirators, and his purpose behind that is to murder Caesar because he suspects him of wanting more power. He sees a weakness in Brutus’s character, in that he can be easily convinced, and Cassius takes advantage of this to suggest to Brutus that Caesar seeks too much power. He tells Brutus that because he cannot clearly see himself, he (Cassius) will act as Brutus’s eyes: “I, your glass, / Will modestly discover to yourself / That of yourself which you yet know not of” (73-75). He flatters Brutus, telling him he has “hidden worthiness” in his eye (63), and that he knows “virtue to be in” him (97).
"Why, man, he doth bestride the narrow world like a Colossus..."
Cassius has noticed Caesar's growing power and believes that he could be dangerous if given absolute power. Cassius is different than Brutus is these fears and concerns, though. Cassius is riddled with jealousy about Caesar's new found power. Several times he reminds Brutus how equal they should all be according to their stations in life and how easily one of them could be in power also.
Even with that jealousy, though, Cassius understands what the Roman republic is all about. He questions what kind of a country they have become when one man holds all the power.
what is the reason the cobbler tells Flavius and marullus he is leading the people through the streets