In "Julius Caesar," Brutus makes the classical mistake of assuming that because he is an idealistic, rational man the crowd, too, will be rational and revere the same ideals as he. Added to this, he believes that Marc Antony is an honorable man who poses no threat to him and his fellow conspirators--whom he has also misjudged.
In his speech, therefore, he appeals to the reason of the crowd. He tells the crowd to condemn him as wrong if he is not reasonable:
Censure me in you wisdom, and awake your senses, that you may the better judge.
He explains that he has slain Caesar not because he did not love him, but because he loved Rome more. In other words, the welfare of the state took precedence over the welfare of the man. Brutus is concerned with the welfare of Rome, not just Caesar. Thus, he appeals to the logical abilities of the crowd as well as their ideal of patriotism:
Who is here so base [low], that would be a bondman?...Who is here so rude [ignorant], that would be a Roman? If any, speak: for him have I offended. Who is here so vile, that will not love his country?...I pause for reply.
When the crowd shouts "None," Brutus feels he has won his argument and he concludes, stating the the whole matter of Caesar's death is on record in the Capitol. Then, as Marc Antony enters with Caesar's body, Brutus remarks,
here comes his body, mourned by Mark Antony, who, though he had no hand in his death, shall receive the benefit of his dying, a place in the commonwealth (he offers Mark Antony a political position), as which of you shall not? With this I depart, that, as I slew my best lover for the good of Rome, I have the same dagger for myself, when it shall please my country to need my death.
Of course, these last lines of Brutus express his strong patriotism; he will die for Rome if Rome demands his death. An example of situational irony exists here since in the final act of this play, Brutus does die for what he believes is the good of Rome, once again exemplfying what he has been criticized for: his tragic flaw of philosophical commitment to principle.