On page 66, what does the quote "By the time the pile was built, they were on different sides of a high barrier" mean? It was right after Jack returns with the hunters and has killed a pig. They let the fire go out and missed their chance to get rescued from a ship that passes by the island. It has something to do with drawing the line between Ralph's side and Jack's side I think. Help? :)
I believe you are on the right track with your thinking. The episode of Jack letting the fire go out while hunting a pig really represents the breaking point for Jack and Ralph being able to work together on the same team. Their focuses have become completely different, and Jack no longer thinks getting home is the most important thing, while for Ralph, that goal is becoming increasingly important.
Both boys want to be the leader, but each presents a very different vision of what the leader needs to do. Jack at this point begins to more fully give in to his "id," focusing on what brings him pleasure (food, hunting, camouflage, fun), while Ralph is more and more seeing the value in Piggy's "super ego," which holds to following the rules and keeping the importance of getting "home" at the forefront - which requires keeping the fire going. Ralph, the "ego," wants to maintain a balance, but he finds himself having to stand more clearly and directly against Jack as a result of this incident.
Jack's pride/stubbornness and Ralph's anger/frustration keep the two boys from ever truly getting over this incident - the "barrier" is too "high" - but at this point, Jack is still not able to completely write off Ralph's authority, so he takes out his own anger on Piggy instead, breaking one of the lenses in his glasses. The vision of the super ego is starting to fade on the island.