Friar Lawrence, from Romeo and Juliet, is central to the development of the plot and will unwittingly contribute to the ultimate tragedy. As the opening passage of Act II, iii reveals, he has a trusting nature and this will contribute to him underestimating the intensity of Romeo's feelings and his intent. It is apparent, even as the Friar speaks of the smiling "morn" and the "frowning night"(1), that he sees the conflict around him and how it is affecting everyone.
Friar Lawrence speaks of the healing power of medicinal plants and compares them to the feud between the Capulets and the Montagues. He is considering how medicine, "being misapplied," (21) and despite its healing properties, can serve as a "poison," to the point that the "canker death eats up that plant."(30) He also worries about the two families and how the feud between them is in danger of doing the same thing unless it is resolved. As long as "two such opposed kings encamp"(27) and continue to hold grudges, he says that, "man as well as herbs" cannot thrive and, may in fact, prove disastrous.
The Friar is well aware how contradictory Nature can be as "the earth that's nature's mother is her tomb."(9) Everything on earth has a purpose which is clear when he says,"For nought so vile ...but to the earth doth give,"(17-18) reminding the audience that Man should not question the function of other living things but should try to make "fair use" of what he has. The Capulets and Montagues should not concentrate on the failings of each other as they both possess "grace and rude will" (28). Unfortunately, due to man's nature, if he allows the "vice" to override the "virtue," others will suffer. If the families allow their hatred to endure, "where the worser is predominant" (29), they, like all of mankind, will suffer the consequences. His words forewarn the audience as he recognizes the precarious situation but he cannot anticipate its consequence or the fact that his words are almost a prophesy of future events.