Mercutio begins by mocking Romeo's lovesick state and compares his infatuation with Rosaline to a religious devotion. He argues that love is a blind and impulsive emotion, driven by mere physical attraction and devoid of any rational thought. Mercutio's speech is filled with colorful imagery and rhetorical flourishes that emphasize the irrational and unpredictable nature of love. He describes love as a "madman" who "bites his thumb at Reason" and likens it to a "figure in a rich man's garden of state," something ornamental and decorative but ultimately lacking in substance.
Mercutio's speech also highlights the superficiality of societal norms and expectations, particularly in matters of love and relationships. He criticizes the conventional social conventions that dictate how people should behave and express their emotions. Mercutio's speech challenges these norms and encourages individuals to embrace their passions and desires, even if they deviate from societal standards.
Overall, the theme of Mercutio's speech is that love is a powerful and unpredictable force that defies rational explanation and societal expectations. Mercutio's witty and provocative remarks serve to underscore the play's central themes of love, fate, and the consequences of impulsive actions.