What is the irony in The Lord of the Flies

Considering William Golding's Lord of the
Flies as a whole, the greatest irony is that the boys, who escape war and
death by their saving arrival on a paradisiacal island far removed from the "evils of
society" degenerate into worse creatures than they would have become if they had
remained in their homeland.  For the "evils of society," ironically, lie within the
human heart; evil is inherent in man, the "beast" is he, as Simon discovers.  So, just
as in the Garden of Eve where it is Adam and Eve who commit the evil act, so, too, is it
in Lord of the Flies.  Interestingly, Golding eliminates any Eve from the situation to
prove that the evil is inherent and not caused by any temptress or anyone else that can
be blamed.  As the Lord of Flies hangs in space before Simon, it
says,

'Fancy
thinking the Beast was something you could hunt and kill!' said the head.  For a moment
or two the forest and all the other dimly appreciated places echoed with the parody of
laughter.  'You knew, didn't you?  I'm part of you?  close, close, close! I'm the reason
why it's no go?  Why things are what they
are?'