The first act of Shakespeare's Romeo and Juliet tells the audience in its opening lines what the outcome of the play is going to be. The playwright begins with what appears to be simple duality: two households; two lovers; two deaths. On the surface, this seems as simple as "black and white", but in reality it becomes much more complicated when the two lovers turn out to be members of two warring households. Furthermore, and ironically, the deaths of these two lovers helps to resolve the strife between the two households.
Thus, the deaths of Romeo and Juliet brings an end to the quarrel between the Montagues and the Capulets. Moreover, Shakespeare implies that there deaths were the only thing that could put an end to the quarrel.
Not only do we find strife between the two families, but we find that the two central characters are being pulled in different directions by the various aspects of love. Juliet is assailed by the practical side of love, the side of love that marries and produces children. Romeo is challenged by the emotional side of love, which, according to Mercutio, he should treat roughly if he is treated roughly by it.
By the end of Act 1, Romeo and Juliet have met one another and are immediately captivated by one another. Unfortunately, they also discover that their families are on opposite sides of an age-old quarrel. Accordingly, Juliet exclaims,
Thus, at the end of the Act, Shakespeare returns to the same sorts of paired opposites with which he started: love and hate. This pair is seemingly simple, but, once intertwined, can create an incredibly complex situation, as it does in this play.