I need to know how to find a theme for a seminar paper about Lord of the Flies by William Golding.

The predominant theme for Lord of the
Fllies is that without civilization humans revert to their more base, or
savage natures. Author William Golding showed us through the boys who crash landed on
the deserted island that people are naturally evil. Left alone without structure or
rules, humans will take care of themselves first, bully others, and eventually
kill.

Jack, at the beginning of the novel, couldn't even
bring himself to kill a helpless pig. He had been taught by adults in his civilized
society that killing was wrong. However, after the structured society the boys had built
broke down, Jack (after hiding behind his painted face) not only killed a pig, but
eventually killed people.

A good way to find a theme in a
piece of literature is to ask yourself, "If someone asked me what life lesson I learned
from reading this piece, what would it be?" Avoid summing up your answer in a
predictable cliche, but use your own words to say what the work was
about.