Each of the main characters in L.O.F. symbolize something from greater society. Jack represents unbridled lust for power and control. He is the autocratic dictator that riddles our history; he is the boy manifestation of Stalin, Hitler, Franco.....Early in the novel Jack is presented as a harsh leader of his choir,
"His face was crumpled and freckled, and ugly without silliness....The tall boy (Jack) shouted at them "Choir! Stand Still!" Wearily and obedient, the choir huddled into line...."
Jack feels the need for violent display to validate his very existence. He stabs trees, attacks Piggy and sets himself up as an antagonist just waiting to take control. From here Jack's progression to an autocratic dictator seems a natural transition. Jack quickly realizes that, with no adults on the island, he can drop what few "civilized" traits he has and embrace the sociopath that he was always meant to be. By the end of the novel Jack's dream is fulfilled. He has set himself up as sort of a king/demi-god, "Jack, painted and garlanded, sat there like an idol...." In the end Jack's hunger for destruction would have been his own undoing. All dictators fall sooner or later. The fact that they get saved is merely Golding's Deus ex Machina (God inside the machine). With Ralph gone, there would be nobody obvious to hate and that would have quickly have been the beginning of the end for Jack and the rest of the boys.