The major difference historically between the leadership of Julius Caesar and the leadership of Brutus has to do with their fundamental characters and ethical positions. Brutus is a follower of Stoic philosophy and concerned with abstract principals and justice. He follows what he considers to be right, such as the abstraction of the Republic and values that more than how that concept may affect individuals. Julius Caesar, known for pandering to the mob, is more concerned with people than ideas and is more malleable in terms of listening to and being influenced by people, but because of this is eventually led to become a tyrant.
One of the main differences also lies in the fact that Brutus is influenced by the image of his eminent ancestor, the Brutus that led the revolt against the last king, Tarquin and overthrew the monarchy: "There was a Brutus once", I. 2. 159. Thus, he is against Caesar, in spite of his tenderness toward him, because he is determined to protect Rome from Mark Anthony's attempts at satisfying his own ambition. Although Caesar refused the crown, Brutus thinks Rome is in danger: "He would be crowned. How that might change his nature, that's the question." The two characters' leadership styles are obviously linked to the fact that Brutus is a Republican whereas Caesar has dreams of imperial grandeur: "I do know but one ... and that I am he", l. 68-70. Yet, Caesar is paradoxically portrayed as weak since he is almost deaf ("For always I am Caesar...for this ear is deaf, I.2. 212-213) and he has the "falling sickness". (I.2.248). By contrast, ironically, Brutus, after shortly wavering over his role in the conspiracy, acts with remarkable single-mindedness while Caesar appears almost fickle and whimsical (He changes his mind and eventually meets his death in the Capitol).