Julius Caesar, thou art mighty yet!
Julius Caesar, you're still powerful!
Marcus Brutus · Act 4, Scene 3
After Cassius and Titinius kill themselves, Brutus realizes that Caesar is still winning — his ghost, his name, his will all more powerful in death than in life. The line is devastating because it shows Brutus understanding, too late, that he has accomplished nothing. The murder of the man did not kill the myth, and the conspirators' grand gesture of liberation has only unleashed chaos and their own destruction.
There is a tide in the affairs of men, Which, taken at the flood, leads on to fortune; Omitted, all the voyage of their life Is bound in shallows and in miseries.
There is a time in men's lives, When, if they act on opportunity, it leads to success; But if missed, their whole life Is stuck in struggle and failure.
Marcus Brutus · Act 4, Scene 3
Brutus argues with Cassius about whether to march to Philippi, insisting that fortune requires immediate action. The lines are famous because they have become proverbial on the nature of opportunity and timing. They also reveal Brutus's fatal flaw: he believes he controls time and tide, when in fact he is being swept toward his doom — a doom he hastens by seizing what he believes is his moment.
Why comest thou?
Why are you here?
Marcus Brutus · Act 4, Scene 3
Caesar's ghost materializes in Brutus's tent at Sardis, and Brutus demands to know why. The line sticks because it is the only moment Brutus addresses the consequence of his crime directly, face to face with the dead. The ghost's answer — that it will see him at Philippi — tells Brutus that his actions have already sealed his fate.