Read the excerpt from act 4, scene 3, of The Tragedy of Julius Caesar . [ BRUTUS: ] Messala, I have here receivèd letters, That young Octavius and Mark Antony Come down upon us. . . . MESSALA: Myself have letters of the selfsame tenor. BRUTUS: With what addition? MESSALA: That by proscription and bills of outlawry, Octavius, Antony, and Lepidus Have put to death an hundred senators. BRUTUS: Therein our letters do not well agree. Mine speak of seventy senators that died By their proscriptions, Cicero being one. CASSIUS: Cicero one! MESSALA: Ay, Cicero is dead, And by that order of proscription. What is the central idea of this excerpt?