The title character of William Shakespeare's play Julius Caesar is killed by his so-called friends about halfway through the play. Brutus was Caesar's close friend, yet he participated in the murder. To his credit, it was not an easy decision for Brutus to join in with the others; to his discredit, his self-deliberations were not enough and he was too easily swayed.
Brutus finally joins the conspirators because he allows himself to be convinced that Caesar was going to do nothing but grow in his ambition, something that would eventually become detrimental to the country.
After the assassination, Brutus tries to calm and comfort the upset crowd. He reminds the crowd that he was Caesar's friend and he loved him--but he loved Rome even more. He makes that argument by saying it was
not that I loved Caesar less, but that I loved Rome more.
He tries to convince them that he saw it as his duty to his country to kill the impending threat which Caesar's overreaching ambition would have cost them all. He makes the point another way:
As Caesar loved me, I weep for him; as he was fortunate, I rejoice at it; as he was valiant, I honor him; but as he was ambitious, I slew him.
At the end of his speech, Brutus gives his fellow citizens a choice. Either they could keep Caesar or they could be glad that Brutus and the others saved them from such a power-hungry and ambitious leader. He goes so far as to predict what Caesar would have done to them, including taking away their citizenship in this Republic. Brutus ends this fear-mongering with the conclusion that since no one would have wanted that to happen, "none have I offended."
This is a false choice, of course, but the people buy it and are moved to forgive; however, this feeling is short-lived. Antony follows Brutus and gives a moving speech which appeals to the people's emotions and moves them the other way.
For more insights and interesting analysis on this and other Shakespeare plays, as well as Shakespeare himself, see the excellent eNotes links attached below.
Shakespeare's Julius Caesar is so very relevant today, especially when the reader examines the characters as representative of personality types. Brutus is, of course, the ideologue and his counterpoint, Cassius, is the practical-minded man; however, in order to solicit the aid of Brutus in the conspiracy, Cassius knows he must feign the ideologue because rarely does an ideologue stoop to doing what is practical or exigent.
Therefore, even though he has been swayed by forged letters thrown over his orchard wall, even though his wife has had premonitions in her dreams the night before, and even though Brutus has little or no empirical proof that Caesar does want to become emperor, in his mind previously praised by Cassius, he wonders if Caesar will continue to be just and honorable (as he has been) if he should be given the power of an emperor. Finally, then, based solely upon his personal perceptions and ideology, which have been clouded by Cassius's machinations, Brutus decides--objectively, he believes--that Caesar must be killed on theory. He feels Caesar might become tyrannical:
...think of him as a serpent's egg
Which hatched, would as his kind grow mischievous. (2.1.32-33)
In his idealism Brutus also fails to comprehend the warnings of Cassius about Marc Antony and his practical advice to slay him. Nor does he listen to Cassius's most practical advice that Antony can do irreparable damage to them and to Rome and he should be immediately killed. Instead, the idealistic Brutus trusts Antony to be honorable, too. Of course, Brutus makes a grievous mistake and Antony in his personal revenge, initiates a civil war, the worst condition which a country can suffer.
Antony, who understands people, creates the seeds of doubt about Brutus in the minds of the pleblians, when previously, Brutus has eloquently and idealistically delivered his message that he killed Caesar because he loved Rome more. Earlier he has said,
...and then is death a benefit
So are we Caesar's friends, that have abridged
His time of fearing death. (3.1.)
And, it is this message that he delivers to the Roman citizens, asking the rhetorical question,
Had you rather that Caesar were living, and die all slaves, than that Caesar were dead, to live all free men? (3.1.)
Thus, Brutus killed Caesar on theory, because of his idealism. This is a fragile argument if the character of Brutus as anything less than noble can be established. Indeed, defamation is exactly what Marc Antony has accomplished as he brings forth actual documents and practical decisions of Caesar into his argument. He creates questions about the integrity of the assassins. "For Brutus is an honorable man; so are they all honorable men."
Truly, "Between the Idea and the Reality....lies the Shadow" as T. S. Eliot wrote. Brutus, the idealist brings civil war onto the Romans and shatters the State. Idealism rarely works because it is never practical.
Please omit the last 2 lines, inadvertently pasted from another source.