Brutus is in his orchard. It is night and he calls impatiently for his servant, Lucius, and sends him to light a candle in his study. When Lucius has gone, Brutus speaks one of the most important and controversial soliloquies in the play. He says that he has "no personal cause to spurn at" Caesar, except "for the general," meaning that there are general reasons for the public good. Thus far, Caesar has seemingly been as virtuous as any other man, but Brutus fears that after he is "augmented" (crowned), his character will change, for it is in the nature of things that power produces tyranny. He therefore decides to agree to Caesar's assassination: to "think him as a serpent's egg, / Which, hatched, would as his kind, grow mischievous, / And kill him in the shell."
Lucius re-enters and gives Brutus a letter that has been thrown into his window. The various conspirators — Cassius, Casca, Decius, Cinna, Metellus Cimber, and Trebonius — now arrive. Cassius proposes that they all seal their compact with an oath, but Brutus objects on the ground that honorable men acting in a just cause need no such bond. When Cassius raises the question of inviting Cicero into the conspiracy, Brutus persuades the conspirators to exclude Cicero from the conspiracy. Cassius then argues that Mark Antony should be killed along with Caesar; Brutus opposes this too as being too bloody a course, and he urges that they be "sacrificers, but not butchers." It is the spirit of Caesar, he asserts, to which they stand opposed, and "in the spirit of men there is no blood."
When the conspirators have departed, Brutus notices that his servant, Lucius, has fallen asleep. At this moment, Portia, his wife, enters, disturbed and concerned by her husband's strange behavior. She demands to know what is troubling him. She asserts her strength and reminds Brutus that because she is Cato's daughter, her quality of mind raises her above ordinary women; she asks to share his burden with him. Deeply impressed by her speech, Brutus promises to tell her what has been troubling him.
Portia leaves, and Lucius is awakened and ushers in Caius Ligarius, who has been sick, but who now declares that to follow Brutus in his noble endeavor, "I here discard my sickness." They set forth together.
