Julius Caesar: Novel Summary: Act 4, Scene 1

 At Antonys house in Rome, Antony, Lepidus and Octavius are negotiating about who should be killed. Lepidus accepts that his brother must be one of them, but on condition that Publius, Antonys nephew, also dies. Antony consents. 
Antony sends Lepidus on an errand, and then complains to Octavius that Lepidus is not worthy to be one of the three leaders of the Roman Empire. When Octavius points out that Antony just accepted Lepiduss vote on a matter of life and death, Antony replies that Lepidus has his uses, but is of no more worth than a beast of burden, which having carried the load required of it can be dispatched to a pasture. Octavius protests that Lepidus is a brave soldier. Antony replies that so is his own horse. And just as a horse has to be trained, so Lepidus is a follower, not a leader. He has to be taught what to do. He should be considered a tool, to be used by others.  
Antony informs Octavius that Brutus and Cassius are raising an army against them, and they must prepare to respond.  
This scene shows the balance of power in the triumvirate. Lepidus is of no consequence, and Antony, as the older man and more experienced soldier, has the upper hand over Octavius.