Why is the conversation between Mercutio and Benvolio in Act III scene I ironic? (In the beginning)?What are the similarities and differences between the two in the beginning of the Scene?
The conversation between Benvolio and Mercutio in the first scene of Act III is ironic because initially Mercutio joking plays the role of the calm, rational one. But after Mercutio jokes that Benvolio quarrels too much, Mercutio himself immediately starts a real argument with Tybalt.
That Mercutio is just joking with Benvolio at the beginning of the scene is apparent from his playful language:
Thou wilt quarrel with a man for cracking nuts, having no other reason but because thou hast hazel eyes....Thy head is as full of quarrels as an egg is full of meat, and yet thy head hath been beaten as addle as an egg for quarreling. (3.1.19-25)
But when Tybalt arrives, Mercutio's language becomes more seriously taunting as he calls Tybalt "Prince of Cats" and "rat-catcher." Then Mercutio refuses to leave; this action is provocative, especially since Tybalt is known for his quick temper and his animosity toward Montagues and any of their friends. When Benvolio tries to warn the two men that they are quarreling in a public square where everyone can see them, the antagonistic Mercutio continues to stay where he is.
Therefore, after joking with Benvolio about quarreling, Mercutio ironically starts an argument with Tybalt.
Mercutio accuses Benvolio of being hot-tempered and willing to fight, especially when the temperature climbs. Mercutio's name alone suggests that, like the element mercury, he is the one with the low boiling point. It is ironic that Mercutio would make that statement about Benvolio, whose name means "one who shows good will and kindness." The images that Mercutio uses to accuse Benvolio of instigating fights do not fit with his character; for example, he accuses Benvolio of being the type of person who would "quarrel with a man that hath a hair more, or a hair less, in his beard" than he has or "for cracking nuts, having no other reason but because [he- Benvolio] hast hazel eyes" (III, i, lines 16-19). These behaviors are more fitting of Mercutio himself. In this scene, Mercutio is "punchy" and looking for an excuse to fight. That's why he so willingly taunts Tybalt when the young Capulet comes looking for Romeo shortly after this conversation.