The funeral oration of Marc Antony in Shakespeare's Julius Caesar is a stellar piece of rhetoric. One rhetorical technique that Antony uses is repetition; however, his repeated phrase is contradictory to what Brutus in his previous address has claimed. For, Brutus has sworn that he loved Caesar, and it was because he loved Rome more that he felt it necessary for Caesar to be removed from power.
Marc Antony takes this very thesis of Brutus's speech, the very reason that makes the Roman people accept Brutus's reasoning, and skewers it, creating doubt in the minds of the crowd as he repeats three times [always a significant number!] with verbal irony,
But Brutus says he [Caesar] was ambitious,/And Brutus is an honorable man (III,ii)
The effect of Antony's ironic suggestions of a different meaning for the words of Brutus as he repeats them is that the Romans begin to think about what is said, weigh the meaning, and, eventually, change their minds about Brutus's honor. Indeed, irony can be a persuasive tool for the accomplished speaker or writer.
Antony uses much verbal irony (says one thing but means another as an indirect means of persuasion). His overall goal is to rally the people behind him, his words, and Caesar, but Antony says just the opposite: "Let me not stir you up / To such a sudden flood of mutiny."
There are three types of verbal irony: sarcasm, overstatement, and understatement. See examples below:
Sarcasm: "The noble Brutus."
Sarcasm: "Brutus is an honorable man."
Overstatement: "O, you gods, how dearly Caesar loved him (him)!"
Overstatement: "...put a tongue / In every wound of Caesar that should move / The stones of Rome to rise and mutiny."
Understatement: "You are not wood, you are not stones, but men."
Understatement: "The evil that men do lives after them."
Understatement:"I am no orator..."
I think that irony is the most powerful rhetorical device that Antony uses in his speech in memory of Caesar. He constantly says that Brutus was an honorable man when he means just the opposite.
In his speech, Antony keeps telling the people about bad things that Brutus has done, each time ending by saying that Brutus is an honorable man. By doing this, Antony is highlighting the fact that he thinks Brutus acted dishonorably. The people agree with him because of how effective his irony is. This is shown by their anger at Brutus and the conspirators.