Jack's separation from Ralph signals his final break from civilization. In many ways, Ralph had been the moral voice for the boys, insisting on shelters, fire for rescue, and rules for the beach. When Jack finally declares, "I'm not going to play any longer. Not with you," his statement also signifies a break from Ralph's rules and society's conventions (127). Jack will now be free on the island to do things his way.
Shortly after, Jack, joined by his hunters, kills the sow, thus beginning his downward spiral into savagery and violence. He attacks Ralph and Piggy on the beach, stealing Piggy's glasses. Later, after the boys paint their faces and dance on the beach, Simon is violently killed by the mob of boys, and the violence will continue to escalate until the end of the novel when Jack plans to hunt and kill Ralph.