What does the island symbolize in Lord of the Flies?
The island represents an environment for a Rousseau-type experiment on Natural Man.
Jean-Jacques Rousseau, an Enlightenment thinker, held that natural man—man free from all but his innate nature—is not controlled or dominated by any social organization of men and can be as he was naturally born to be. Thus, without the controls of society, man is spiritually and psychologically free to exercise his innate goodness.
Golding uses the island as an Eden-like setting in which the boys are free of the constraints of society, constraints represented by the absence of adults. Further, the boys' stripping off of their clothes signifies the total freedom from restraints in which the boys exist. However, the experiment fails because Jack, and especially Roger, demonstrate an innate evil. This inherent evil is demonstrated as early as Chapter 4 as Roger throws stones near little Henry, who he follows as the littlun walks down to the beach. While Henry sits and plays, Roger throws stones near him because "there was a space round Henry...into which he dare not throw." This space is the result of the conditioning of a "civilization that knew nothing of him and was in ruins."
Others also demonstrate this innate evil later in the narrative as they engage in primitive, ritualistic dancing that crescendos into the brutal beating of the Christ-like Simon, who has encountered evil face-to-face in the form of the Lord of the Flies. The boys then continue to descend into savagery and pursue Ralph, even setting fire to the island, destroying everything.
William Golding's novel acts as a counterpoint to R. M. Ballantyne's Victorian adventure story The Coral Island in which English boys prove their mettle and innate goodness as they defeat savages and establish order on the island. In Lord of the Flies, the English boys fail the Rousseau experiment and descend into savagery themselves, demonstrating the innate evil of man.