In the second scene of Act One in Shakespeare's Julius Caesar, Cassius relates to Brutus the story of saving Caesar's life. Caesar dared Cassius to swim with him in the Tiber River to reach a certain point before Caesar could. However, before they reach their destination, Caesar calls for Cassius' help to save him from drowning. (I.ii.106-121) Cassius saves Caesar. Since then Caesar has become highly regarded: so much so that the people are talking of making him their king—and this infuriates Cassius.
Cassius is angry that as Caesar has grown in popularity and power, he has forgotten that Cassius saved his life. He resents having to bow to a man who owes Cassius his very life, believing that Caesar is no better than Cassius as a citizen of Rome or a man.
Is now become a god, and Cassius is
A wretched creature, and must bend his body
If Caesar carelessly but nod on him. (122-124)
Cassius tells Brutus that they are all born of the same class and have all proven their strength and prowess as men. They should all be equal.
When Brutus expresses concern after hearing shouts from those who would make Caesar a king, Cassius sees an opening by which to win Brutus (who loves and admires Caesar) to join in a plot to assassinate Caesar for fear that in becoming a king, he will abuse his power and become a tyrant.
Cassius stresses the sense that Caesar is becoming an enormously powerful man while men like Cassius and Brutus are left behind with little hope of ever being more than inferior and subordinate "underlings." Cassius explains to Brutus:
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. (145-147)
Cassius postulates that there are times when men can make their own luck—that they can become greater than the circumstances in which they were born. He insists that the problem is not that they are ill-fated (see the reference to "stars"), but that they hold minor or unimportant positions beneath Caesar. Cassius begins to turn Brutus' doubts about Caesar into full-blown realities, suggesting imminent disaster for the Roman Empire. One might argue that without Cassius' prodding, Brutus might never have acted at all. However, Cassius capitalizes on Brutus' misgivings to serve his own wounded ego, and forge the way to bring Cassius what he wants most: the satisfaction of seeing Caesar dead, no longer forced to pay homage to him.
When Casca reports that Caesar collapsed in public, Brutus comments that it is likely in that Caesar suffers from epileptic episodes. Cassius sarcastically notes that Caesar is not suffering from a fall of any kind, but the three of them are.
He fell down in the market-place and foamed at mouth
and was speechless.
'Tis very like: he hath the falling sickness.
No, Caesar hath it not, but you, and I,
And honest Casca, we have the falling sickness. (256-260)
In essence, Cassius is saying that Caesar shows no signs (figuratively) of falling down—based upon his position of importance and the estimation of the Roman citizens. Speaking figuratively, Cassius is saying that because of Caesar's growing power, the true sufferers of a "fall" (referring to losing one's position of prominence) are men like Brutus, Cassius and Casca because they are not being valued as they should be. Cassius has already noted that the name "Caesar" should be no greater than "Brutus" or "Cassius" (lines 148-149). They are "falling" because Caesar is so powerful and he is ignoring them. Whereas Brutus fears Caesar's potential tyranny, the reader must closely question Cassius' motivation. Cassius' actions seem based upon nothing more or less than the jealousy of this self-serving man. While Brutus acts out of his love and concern for Rome, Cassius is only interested in moving up in the world in any way possible, and he is not above using Brutus to get what he wants. Unfortunately, Brutus allows himself to be drawn into the scheme and becomes (unwittingly) Cassius' pawn.