Lord of the Flies by William Golding outlines the potential for disaster when a group of school boys are left stranded on an island with no "grown ups" and two potential leaders, Ralph and Jack. It is clear from the beginning that there is some competition between Ralph and Jack even after Ralph has been voted as chief. At first it does not threaten the boys' safety and Jack is content to lead the "hunters."
Piggy immediately recognizes the value of the conch and its potential to draw the other boys out. On hearing it, boys come out of the undergrowth and are impressed by the conch—except Jack, who is somewhat irritated that, on responding to the sound of the conch, there is no ship (ch 1). On voting for Ralph as chief rather than Jack, the conch reveals its power and it works well for a while; the boys admire its ability to create order. As the story progresses, the boys desperately grasp at its dwindling power as it becomes less effective in restraining Jack.
The boys become more obsessed with the "beastie" as the plot develops. They are now certain that there is a beast; even Ralph thinks that he has seen it. Significantly, it is Jack who blows the conch (ch 8) after the assumed sighting and takes advantage of the situation in suggesting that Ralph should not be chief. It is important to note how Ralph uses the conch to call order and Jack, who has no respect for it, uses it to cause dissension and disagreement, trying to turn the boys against Ralph and everything that the conch stands for. After Simon's death, Ralph will clutch the conch, rocking himself "to and fro" (ch 10). He is clinging to the remnants of civilization.
The pig's head becomes significant from chapter 8 when Jack kills a pig and uses its head as a "gift" for the beast. His cruelty is apparent and his ability to use fear as a form of power is very noticeable. The fact that Simon speaks to the head and that the head tells Simon that evil lies in everyone foreshadows what will follow as the boys, in their frenzy, mistake Simon for the beast. Talk of the beast and now the pig's head itself have made the beast too real.
- The conch is representative of order and democracy.
- The pig's head is representative of evil and the potential for evil in each of the boys.
- Both the conch and the pig's head signify power but of a very different kind. The conch encourages the boys to respect one anothers' rights whereas the pig's head reveals its power through fear.
- The power of the pig's head that promises to have some "fun" with Simon stresses the warped sense of fun that Jack derives from hunting and killing the pig and confirms his descent into savagery as he fails to distinguish Simon from the beast when Simon, philosophical and kind, is killed.
- The ability of the conch to maintain even a fundamental civil order is lost completely when it smashes at the same time as Piggy, intellectual and logical, is killed.
Ralph's intention in using the conch is to advance the good of all the boys and to ensure safety and rescue. Jack and Roger use the power of fear which the pig's head confirms to gratify their own wanton needs, using the boys and their power over them for "fun."
I found it interesting to interpret Jack, Ralph, and Piggy as a metaphor for the triune conflict of the Id, Ego, and Superego. In that dynamic the conch and pig's head don't necessarily represent inherently political qualities, but rather become symbolic of the more primal conditions of control and chaos. That's why the conch "works" no matter who uses it, and also why Piggy (the Superego) clings so desperately to the power of the conch to provide control and stability. At the same time the pig's head represents the antithesis of control in being the emblem of the most debased and vulgar behavior of Jack (the Id) and his group. On that note, the argument could be made that the white conch shell represents purity because it always handled delicately until it is destroyed in an act of violence; while on the other hand the pig's head represents beastly vulgarity because of the implicit sexual violence of the hunting scene. In between, Ralph (the Ego) is trying desperately to convince the entire group to maintain their identity as boys--not the men or beasts that Piggy and Jack want the group to become.
Also significant is that the book itself is titled after the pig's head and not the conch. But that point of discussion is beyond what I specifically wanted to reply to.