In Act I Scene 4, Benvolio has convinced Romeo to go to the Capulets and partake briefly in the dancing and feasting. Mercutio accompanies them and he begins to mock Romeo's lugubrious comments about love, changing them into licentious metaphors. Romeo, however, will not engage in this banter because he claims to have had a dream in which he learned that attending the feast was a bad idea. At this point Romeo demonstrates the characteristics of the Petrarchan lover; that is, he moans about the loss of his lover and speaks of her in mournful and passionate tones. Hearing Romeo, Mercutio tries to convince Romeo otherwise by telling him to cast aside his melancholy and stop deprecating love:
If love be rough with you, be rough with love.
Prick love for pricking, and you beat love down. (1.4.27-28)
Benvolio, too, encourages Romeo. He suggests that they go in and dance. Still Romeo declines and says that he will not participate. Instead, he will hold the light for them as he believes the evening presages something bad.
In this passage Mercutio's character is developed as one believing in action rather than dwelling in melancholy as Romeo does. As his name suggests, however, Mercutio is mercurial and he can quickly react.