How is Lord of the Flies a story of savagery vs. civilization?

Golding himself discusses the fact that this novel was a
response, in some ways, to Ballantyne's novel "Coral Island," particularly in response
to the way that it portrayed British boys as being immune to the pressures of savagery
or the inner evil of human beings.  Golding felt that it was unrealistic that they would
not give in to the inner evil at least as frequently as any other
people.

By creating the conflict within the novel Golding
sets out his own version of how he feels that these boys will react to the conflict
between savagery and civilization.  Jack represents the evil within the boys and Ralph
and Piggy represent the civilized side of things and the story is of course Golding's
representation of how that conflict would play out.