In Act II, Scene 3 of Romeo and Juliet, the priest Friar Lawrence makes several philosophical observations.
Friar Lawrence meets Romeo early one morning. He deduces that a young man like Romeo would not be up so early, unless he had been upset, or had never gone to bed that night. Romeo admits that he has spent the night wooing Juliet, which was a "sweeter rest" than sleep.
Romeo tells the Friar that he has dumped Rosaline, his previous lover, for Juliet, and that he has "forgot that name [Rosaline] and that name's woe."
*The Friar remarks with a philosophical observation:
Is Rosaline, that thou didst love so dear,
So soon forsaken? Young men's love then lies
Not truly in their hearts, but in their eyes.
The Friar is making the observation that love has less to do with an attraction of souls, and more to do with an attraction of the eyes. How interesting that this observation in the play that is usually considered Shakespeare's most romantic work!
At the end of the scene, the Friar agrees to perform the marriage of Romeo and Juliet, because the marriage will "turn your households rancour [hatred] to pure love"--it will cool off the hatred between the Capulets and the Montagues.
Romeo follows after the Friar in "sudden haste." The Friar tells him to slow down, and offers a philosophical observation:
They stumble that run fast.