Why does Brutus allow Antony to speak at Caesar’s funeral?

Brutus allows Antony to speak at Caesar’s funeral in the hopes that doing so will work to the conspirators’ benefit. Brutus plans to make a speech to the Roman people, outlining the reasons for Caesar’s death, and he tells Antony that he can speak afterward. Brutus instructs Antony to speak well of the conspirators: “You shall not in your funeral speech blame us, / But speak all good you can devise of Caesar, / And say you do ’t by our permission.” Cassius strongly objects to this plan, pointing out that there’s no way to know “how much the people may be moved / By that which he will utter.” Brutus insists, however, that having Antony speak at Caesar’s funeral will help justify the conspirators’ actions in the eyes of the Roman people. Later, this plan goes awry. Although Brutus’s words temporarily win the crowd’s sympathies, Antony goes on to deliver a moving speech full of masterful rhetoric that quickly turns the Roman people against the conspirators, leading to a riot and, later, war. Brutus’s mistake in letting Antony speak derails the conspirators’ cause and leads to tragedy.