As dawn breaks, Friar Laurence collects herbs outside his cell. He muses on the fact that everything on Earth, from herbs to virtues, has some special good, but that any of those things, if misapplied or used in excess, can cause disaster.
The Friar's thoughts on the importance of moderation prove fateful, given the destruction that R and J's passion causes.
Romeo rushes into Friar Laurence's cell. Friar Laurence immediately sees that Romeo did not sleep that night, and is alarmed that Romeo might have slept in sin with Rosaline. But Romeo says he has forgotten Rosaline, and describes his love for Juliet and his desire to marry her.
The Friar's comments on moderation contrast with Romeo's youthful insistence on speed and extreme emotion above all else.
The Friar is suspicious of Romeo's sudden switch from Rosaline to Juliet. Romeo responds that Juliet, unlike Rosaline, returns his love. The Friar comments that Rosaline knew Romeo's "love did read by rote, that could not spell" (2.2.86).
Another clue that before Juliet, Romeo's "love" came from copying romantic poetry rather than experience.
But Friar Laurence also sees an opportunity to end the feud between the Montagues and Capulets, and agrees to marry Romeo and Juliet.
Though he preaches moderation, Friar Laurence gets caught up in his own big dreams of creating peace.