This passage is chock full of oxymorons. An oxymoron is when two words that have different meanings, or connotations, are combined together for literary effect. In this passage, Romeo describes his love for Rosalind as "brawling love," and "loving hate." These, especially the latter, are obviously oxymorons, because their meanings and connotations are very different. Romeo uses them both to comment on the fray that has just taken place between his kinsmen and the Capulets, but also to describe his unrequited and therefor bitter love for Rosalind. He elaborates with more oxymorons, comparing love to a "feather of lead, bright smoke, cold fire, sick health," and so on. His point is that love, while beautiful, can also cause extreme pain and sadness, which is especially the case with him. Taken in this light, this passage can be read as foreshadowing the rest of the play--the love shared by Romeo and Juliet is indeed beautiful, but it is also, in the context of the feud between their two families, destructive and tragic. Shakespeare uses oxymorons to underline this duality.