In The Lord of the Flies the civilizing impulse is represented by a number of key characters and symbols, including Ralph, Piggy, and the conch shell the boys use to call meetings. The instinct to savagery is represented by Jack, Roger, the tribal hunting dance, and the decapitated sow's head that comes to be known as the Lord of the Flies. The conflict between Jack and Ralph, as it develops, represents the conflict between the civilizing impulse and the impulse to savagery both within the individual and within society as a whole, as the boys marooned on the island gradually reject the restraints of civilization in favor of a primal, violent, primitive existence of hunting, feasting, and homicide.
The one truly complicating element in the novel is the character of Simon. Whereas Piggy represents the scientific, intellectual, and rational aspects of civilization, Simon seems to represent a kind of innate, spiritual human goodness, deeply connected with nature and in its way as primal as Jack and Roger's primal evil. The other characters in the novel abandon moral behavior as soon as civilization no longer imposes it upon them: they are not innately moral; they have simply been conditioned to act morally by the adult world, and by the threat of punishment. This is true even of Ralph and Piggy to an extent; in the psychology of the novel, the civilizing impulse is not as deeply rooted in the human psyche as the savage impulse. But Simon continues to act morally on the island; he behaves kindly to the younger children, and he is the first to realize the problem posed by the beast and the Lord of the Flies--that there is no external monster, but that rather a monster lurks within each human being. This idea finds representation in the sow's head, and eventually stands as the moral conclusion of the novel. The main problem of the book is the idea of human evil; against this, Simon seems to represent an idea of essential human goodness--yet his brutal murder by the other boys near the end of the book indicates the scarcity of that goodness amid an overwhelming abundance of evil.