Explain in detail the power of speech in "Julius Caesar."

That words are powerful is evidenced throughout all the writing of Shakespeare.  In "Julius Caesar" the persuasive power of language is first exemplified in Cassius's convincing Brutus of Rome's need to be rid of Caesar because he is a tyrannt.:

Why, man, he doth bestride the narrow world/Like a Colossus, and we petty men/Walk under his huge legs and peep about/To find ourselves dishonorable graves./Men at some time are masters of their fates:/The fault, dear Brutus, is not in our stars,/But in ourselves, that we are underlings./Brutus and Caesar:  what should be inthat "Caesar"?/Why should that name be sounded more than yours?/Write them together, yours is as fair a name.../Rome, thous hast lost the breed of noble bloods!....There was a Brutus once that would have brooked/Th'eternal devil to keep his state in Rome/As easily as a king. (I,ii,135-161)

After this persuasive argument to his sense of pride and honr, Brutus promises to consider Cassius's words, declaring that before now he has pondered the same things.  Of course, Brutus is later swayed by his love of Rome: Caesar's "abuse of greatness" must be ended, so he and the other conspirators assassinate Caesar.

After Caesar's death, Brutus addresses the people of Rome. In order to explain the conspirators' slaying their ruler Brutus appeals to their abilities to reason:

If there be any in this assembly, any dear friend of Caesar's, to him I say that Brutus' love to Caesar was no less than his.  If then that friend demand why Brutus rose against Caesar, this is my answer:  Not that I love Caesar less, but that I loved Rome more.  Had you rather Caesar were living, and die all slaves, than that Caesar were dead, to live all free men? (III,ii, 19-24)

Brutus ends his persuasive speech  with a final rhetorical question:  "Who is here so vile, that will not love his country?" (III,ii, 33)

In the most salient example of the power of speech, Marc Antony returns to give a funeral oration for his friend, Julius Caesar.  Facing a hostile audience after the speech of Brutus, Marc Antony cleverly begins with "Friends, Romans, countrymen..." (III,ii,74), aligning himself with the audience.  Appealing to their emotions rather than their intellects, Antony is able to better persuade than Brutus, for he wins over the crowd by means of his effective pauses and  his emotive repetition of phrases.

With brillant verbal irony, Antony declares that he will not attempt to stir the crowd:

I come to bury Caesar,, not to praise him....The noble Brutus / Hath told you Caesar was ambitious.If it were so, it was a grievous fault,/And grievously hath Caesar answered it.  Here, under leave of Brutus and the rest/(For Brutus is an honorable man,/So are they all, all honorable men), (III,ii,74-84)

Employing this verbal irony, Antony creates the illusion that he has not come to stir the crowd.  When the crowd's resistance to him is lowered, Antony begins his manipulation, insinuating that Brutus and the others are, indeed, not honorable.  His tone and effective pauses along with the repetition of the phrase "so are they all, all honorable men" underscore the contradictions of what has happened.  T Antony,then,directs the crowd to Caesar's wounds. With emotional appeal, Antony reminds them of Caesar's love for Brutus, so the stab from Brutus was the "most unkindest cut of all" (III,ii,184).  He ends with his final argument and rhetorical question:

in every wound of Caesar's that should move/The stones of Rome to rise and mutiny (III,ii,230-231)

Here was Caesar!  When comes such another? (III,ii,253)