How many ages hence
Shall this our lofty scene be acted over,
In states unborn and accents yet unknown!
Cassius speaks these words in Act 3, Scene 1 just as he convinces the exultant conspirators to smear their hands with Caesar's blood. At this moment of highest drama, one of the chief actors of this piece draws attention to its theatricality. Why?
It is a common trope of Elizabethan thinking to draw attention to life's fictions. Queen Elizabeth staged many public processions and scenes and created and lived the role of the Virgin Queen. Her subjects were both her fellow actors and her audience. Playwrights of the time, and Shakespeare in particular, made use of this metaphor in a number of ways (for an interesting example, take a look at Hamlet and the play within a play, The Mousetrap).
In Julius Caesar, theatricality is both an example of one of the major themes of the play, persuasion, and a comment on the deterioration of the state of Rome. A number of characters use theater in an attempt to persuade.
