This scene introduces the Friar, a philosophical man who wishes to heal the rift between the families. His discourse on the healing and harming powers of plants will echo loudly later in the play. He will provide Juliet the sleeping potion that she drinks to avoid marrying Paris.
The dual nature within the Friar's plants suggests a coexistence of good and evil. The tension between good and evil is a constant force in this play — a strong undercurrent that conveys fate into the characters' lives. The Friar is a good example. His intentions are good; he wishes to end the feud in Verona. His plan, however, precipitates the tragic end to the play.
As the play progresses, the contentious coexistence of love and hate unfolds. Capulet loves his daughter, but treats her like his personal property. Romeo and Juliet's love exists in an atmosphere electrified by the darkness of the hatred between the families. The Friar's comment that "[t]he earth that's nature's mother is her tomb; / What is her burying grave that is her womb" harkens back to Capulet's statement about his daughter in Act I, Scene 2 — "the earth has swallowed all my hopes but she."
The theme of nature destroying life in order to create life recurs frequently. While an undeniable certainty exists within this natural cycle, the Friar suggests that the deeply flawed human being imposes some degree of mutability on the entire process. Good and evil coexist in imperfect harmony. "Virtue itself turns vice, being misapplied; / And vice sometimes by action dignified."
