In the opening scene of "Romeo and Juliet," when the confrontation between families begins, Benvolio speaks to Abraham and Sampson and Gregory when they pull their swords: "Part fools! Put up your swords. You do not know what you do"(I,i,37-38). However, Benvolio loses his temper when the fight heats up. Lord Montague enters and shouts for his sword. But, Lady Montague steps in, "Thou shalt not stir one foot to seek a foe" (I,i,53). Then, Montague asks who started the quarrel; Benvolio gives a cool, rational explanation: He tells Montague that he drew his sword to part the quarreling servants when "the fiery Tybalt, with his sword prepared..."(I,i,,81,82), so he and the others had to defend themselves. In Act IV, scene iv, Benevolio asks Mercutio to "stop there" in his mocking of Romeo.
When Romeo bemoans his jilting by Rosalind, Benvolio makes light of Romeo's confession so that he will calm down: "Alas, that love,..Should be so tryannous and rough in proof!"(I,i,141,142). Lord Capulet echoes Benvolio's speech concerning other women and not rushing things in reply to the prince's proposal: "My child is yet a stranger in the world;/Whe hath not seen the change of fourteen years"(I,ii,8-9).
Of course there is Friar Laurence's famous soliloquy on moderation in which he reflects,
Nor aught so good but strain'd from that fair use/Revolts from true birth, stumbling on abuse: Virture itself turns vice, being misapplied (II,iii,11-13)