What is the authors purpose for including the following passage? two boys faced each other. there was a brilliant world of hunting, tactics, fierce exhilaration, skill: and there was the world of longing and baffled common sense.

In this case, the purpose of the authors with this passage is to emphasize the rivalry between Jack and Ralph, this is shown as the author explains the differences between Jack and Ralph ideas about survival. This passage shows Ralph would us commonsense, logic and civilized principles to survive through "the world of longing" (what is real) and the "baffled common sense". On the other hand, Jack would use more barbaric strategies such as "hunting" or "fierce exhilaration".

These opposite points of view are confronted during the story as Jack becomes the antagonist and a barbaric leader. While Ralph attempts to be the  civilized leader of the group.

no it who u choose to be. let no one tel u what or who to be;