Shakespeare uses vivid metaphors to express the play’s characters and themes. Often Shakespeare uses subtle word choices to add additional meaning to a phrase. For example, in the second act Brutus remarks that “Cassius… did whet me against Caesar.” The word “whet” suggests the sharpening of a knife blade, a useful metaphor that foreshadows the assassination to come.
"So do you too, where you perceive them thick.
These growing feathers pluck'd from Caesar's wing
Will make him fly an ordinary pitch,(75)
Who else would soar above the view of men
And keep us all in servile fearfulness...."See in text(Act I - Scene I)
Flavius’s metaphor here of Caesar as a bird is likely a reference to the “Aquila,” the eagle the Romans used to symbolize their military might. If Caesar is the eagle, the people in support of him are his feathers. According to Flavius, the key to toppling Caesar lies in drawing the public away from him. We see again the importance of the public’s approval in the complex political landscape of the play.
"Yond Cassius has a lean and hungry look;(200)
He thinks too much; such men are dangerous...."See in text(Act I - Scene II)
Caesar uses this metaphor to compare one's physical appearance to their internal ambitions. He states that "fat men" are content with their lives and therefore not a threat to his rule, while skinny men are "lean and hungry" not only for food but for power. Caesar rightly sees that Cassius threatens his rule and his life. This shows that Caesar is a very perceptive and capable ruler, which works to undermine the conspirator's accusations that he threatens the Roman Republic.
"And that which would appear offense in us,
His countenance, like richest alchemy,
Will change to virtue and to worthiness...."See in text(Act I - Scene III)
Casca uses alchemy–the antiquated practice of turning lead to gold–as a metaphor for the power of political rhetoric. Throughout Julius Caesar, nothing is truly lead or gold, but the right words can make it seem so.
"O, pardon, sir, it doth, and yon grey lines
That fret the clouds are messengers of day...."See in text(Act II - Scene I)
In another illustration of how subjective the readings of the heavens are in the play, Cinna sees the clouds as brows lined with worry over the events of the coming day.
"Since Cassius first did whet me against Caesar
I have not slept...."See in text(Act II - Scene I)
Shakespeare’s use of “whet” is a beautifully subtle choice that serves as both metaphor and metonymy. To whet a knife is to sharpen its blade. In this characterization of Brutus as a knife, we understand both the nature of his potential role in the assassination, as well as a more literal foreshadowing of the knife he will wield in the fateful event.
"Cassius, go you into the other street
And part the numbers...."See in text(Act III - Scene II)
By referring to the public as “the numbers,” Brutus reiterates the idea that the citizens of Rome are a means to an end. To Brutus and Cassius, the public are simply a number that needed to be swayed in order to advance their political agenda.
"And bay'd about with many enemies;..."See in text(Act IV - Scene I)
Octavius echoes Antony’s famous turn of phrase from Act III, Scene I. Leaning over Caesar’s bloodied body, Antony calls for the crowd to “Cry ‘Havoc!’, and let slip the dogs of war” (273). While Antony intended to release the Roman public on the conspirators like a pack of hounds, Octavius now characterizes those same conspirators as dogs “bay[ing]” at him and Antony.
"their names are prick'd...."See in text(Act IV - Scene I)
This is a clever reversal. To say the conspirators names are “prick’d” means they are marked by the pen for death, but specifically in a way that calls to mind Caesar’s stabbing.
"Thou hast described(20)
A hot friend cooling...."See in text(Act IV - Scene II)
In these lines, Brutus calls Cassius’s character into question. Where Cassius had once posed as the ringleader of the assassination, Brutus detects his co-conspirator’s confidence and commitment to the cause shrinking in the aftermath of the violence. It is likely that Brutus is projecting his own “cooling” commitment onto Cassius.
"O murderous slumber,
Layest thou thy leaden mace upon my boy..."See in text(Act IV - Scene III)
This is a strangely gruesome metaphor for sleep, and yet it makes sense in context. Even this rare moment of tenderness—in which Brutus cares for the young Lucius—is troubled by the specter of violence: violence done, and violence yet to come. The soft musicality of these lines, rich with “m” and “l” sounds, is striking as well.
"There is a tide in the affairs of men
Which taken at the flood leads on to fortune;(245)
Omitted, all the voyage of their life
Is bound in shallows and in miseries...."See in text(Act IV - Scene III)
Brutus uses this metaphor to convince Cassius to attack Octavian before their enemy can recruit more forces. He uses the tide to show a natural ebb and flow in war and highlight the importance of timing. If they "take at the flood," or go with the tide, they will more likely be fortunate. If they wait then they will miss the fortunate tide and be left in the "shallows," or miss their opportunity.
"Why, now, blow and, swell billow, and swim bark!
The storm is up, and all is on the hazard...."See in text(Act V - Scene I)
Cassius evokes a nautical image that serves as a reiteration of Brutus’s “tide” metaphor from the previous scene: “There is a tide in the affairs of men, Which taken at the flood, leads on to fortune.” Cassius is implicitly saying that high tide is nigh; it is time to set sail. Note too the dense internal rhymes of the first line.
"Friends, I owe more tears
To this dead man than you shall see me pay.
I shall find time, Cassius, I shall find time...."See in text(Act V - Scene III)
Brutus remains the stoic. As with the news of Portia’s death, he refers to his grief but does not show it. The metaphor of “ow[ing]” tears underscores Brutus’s reluctant relationship with mourning.
"This day I breathed first: time is come round,
And where I did begin, there shall I end;(25)
My life is run his compass...."See in text(Act V - Scene III)
It is not clear whether the day of the battle marks Cassius’s birthday, as he hints. In any event, he understands the imminence of his death and takes on a circular perspective of his life. Time becomes a compass whose needle has spun its full course.