This speech, In the excerpt, Juliet has just learned that her cousin Tybalt is dead, sounding from the mouth of one so young and sweet create a bit shocking. Perhaps she said it in the heat, in an outburst of emotions and her mind did not to think sensibly. Because in the end she still became on the side of her beloved Romeo. It is also possible to say that in this part of the tragedy Juliet the first time shows her character. I think that the author uses so many oxymorons in this excerpt only to show the ardent character of the Juliet.