Brutus, Messala, Cato, and other soldiers enter the field. Brutus urges his men to be courageous. Cato fights boldly and is killed, and Lucilius, pretending to be Brutus, is taken captive. Then Antony enters and, recognizing Lucilius, spares his life and orders that he be treated kindly, in hopes that he will become an ally.
This scene contrasts Brutus’s principled nature with Antony’s calculating one. Just as Brutus once spared Antony, Antony now spares Lucilius. But while Brutus spared Antony because he believed he was as noble as Brutus himself, Antony spares Lucilius for pragmatic reasons: he thinks he can turn him into an ally.