Explain the conflict of the societies for The Lord of The Flies.Societies (Society in the civilized world, and society in the island)

Perhaps the most telling passage of William Golding's
Lord of the Flies is in the description of the
actions of the character Roger, the "slight furtive boy whom no one
knew":

When
Henry tired of his play and wandered off along the beach, Roger followed him, keeping
beneath the palms and drifting casually in the same direction....Roger stooped, pickd up
a stone, aimed, and threw it at Henry--threw it to miss.  The stone, that token of
preposterous time, bounced five yards to Henry's right and fell in the water....there
was a space round Henry, perhaps six yards in diameter, into which he dared not throw. 
Here, invisible yet strong, was the taboo of the old life. Round the squatting child was
the protection of parents and school and policemen and the law.  Roger's
arm was conditioned by a civilization that knew nothing of him and was in
ruins.

This
passage about the sadistic Roger illuminates the struggle that a civilized world has
against the innate evil in the nature of man.  For, once the trappings of society are
removed, or masked, as they first are on the island, man easily degenerates to his
inherently evil nature.  In another passage, when Jack first smears on the colored clay
and turns his half-concealed face to Roger, "Roger understood and nodded gravely."  For,
the mask "liberated from shame and self-consciousness" the rules of
society.

That society in a civilized world is not, of
itself, good either is evidenced by the "parents, schools, policemen, and law" that must
condition and recondition people.  This fact is symbolized by the naval officer who
rescues Ralph as he is "a little embarrassed" and turns his eyes to "rest on the trim
cuiser in the distance," the warship. 

Without the
restraints of a civilized world--those trappings in the form of the rational and more
mature Piggy who is killed by the sadistic Roger--there is anarchy and evil.  Only Simon
recognizeds the innate evil in the boys, represented by Roger "whom no one knew," who
wields the rock, the symbol of "preposterous time."  But, Simon cannot communicate this
knowledge of evil, and he, too, is killed by the hunters of whom Roger is a
part.