It seems to me that the author is suggesting that all men are still savages at heart and that civilization is just a thin veneer which can easily break down when men find themselves in an unstructured setting. (This is what happened to Kurtz in Joseph Conrad's Heart of Darkness.) The boys are particularly susceptible to reverting to savagery on his deserted island because they are young and have not been subjected to much enculturation during their brief lifetimes. What is happening to all of them is happening on a worldwide scale where World War II is raging. There the grown men are also reverting to savagery, and if the war had gone on for many more years, as it does in H. G. Wells' novel Things to Come, civilization would have degenerated into a new Dark Ages. Your thesis for your paper on Lord of the Flies might be something like this:

What happens to the boys on the island is completely natural and inevitable because they are essentially little savages underneath a very thin veneer of civilization symbolized by their school uniforms and their proper English.

In addition to Heart of Darkness, I am reminded of H. G. Wells' short novel The Shape of Things to Come (in which a world war goes on for thirty years); Jack London's little-known short tale The Scarlet Plague; and a story titled "The Portable Phonograph" by Walter Van Tilburn Clark.

Durbanville has provided some amazing thesis statements for you!  I would like to suggest a few others with some instruction as to how to approach your essay.

     The boys truly struggle to survive without an authority figure due to their fighting, bullying, and show of emotion.

[With this particular essay, you would include an introduction about struggles due to lack of authority ending with this thesis.  Your three body paragraphs would be as follows:  first about the boys fighting during the novel, second about the boys bullying each other, and third about the show of emotion as revelation about their struggle.  Your conclusion would include a reworded thesis and then, possibly, an idea of a modern struggle where no authority is present.]

     The reaction to Ralph as the figure of authority shows the boy's immaturity in regards to their ignoring his demands, their verbal reactions, and their preference to play/hunt.

[In this essay, your introduction would begin with the concept of immaturity and filter down to this thesis.  Your body paragraphs would show the boys immaturity by first showing the boys ignoring of Ralph's demands; then by sharing their verbal reactions; and finally exhibiting their obvious preference to play and hunt pigs.  Your conclusion would reword the thesis and then, perhaps, give a modern example of immaturity.]

     The Lord of the Flies is a perfect novel to discuss the "fear of the unknown" in regards to the reality of "the beast," the ignored reality of the paratrooper, and the reactions from any of the boys to their situation.

[In this essay, you would begin by exploring the fear of the unknown and filter to the thesis above.  Your three body paragraphs would be as follows:  the first about the beast, the second about the paratrooper, the third about the revelations due to the boys reactions.  Your conclusion would reword your thesis and then describe a current fear of the unknown.]

Finally, I have included our wonderful eNotes page revealing many quotations you can use as primary source quotes!  With these as evidence, your essay is sure to be a success.  Good luck!

A thesis statement is an invaluable part of an essay as it allows the writer to stay focused on the main purpose of the essay. It is a good idea to reread the thesis statement several times to ensure that the emphasis remains. Basically, a thesis statement supports whatever claims the writer may intend to make and it should persuade the reader, once the supporting evidence has been produced, and convince him to agree with the writer's point of view.  

In Lord of The Flies, there are various topics which a writer could focus on, most of which hinge on the civilization versus savagery theme which William Golding portrays so vividly. Each topic could deal with a different aspect, such as the changes in the boys in the absence of "grown-ups;" the fact that Ralph and Piggy work so hard to maintain order, stressing the importance of the conch; the different priorities of Ralph and Jack as they compete for leadership; the importance of "the beast" and how if affects the decision-making; Jack's complete descent into unrestrained evil and also the brutal loss of innocence that completes the story. 

Potential thesis statements, which would appear in the introductory passage, could be:

1)Jack's behavior and Ralph's inexperience cause the complete breakdown of all sense of decency and human compassion.

The main emphasis here could be on how, despite Ralph's best efforts and Piggy's help, Jack is a stronger character than Ralph, questioning everything and gradually breaking down Ralph's position, persuading the others to join his "tribe."

2)The conch represents the only hope the boys have of maintaining order. It is a symbol of democracy and civilization on the island where the boys find themselves.

Jack has little respect for the conch from the beginning and this is seen in his behavior and his treatment of Piggy. Jack uses and abuses the conch, which indicates his lack of respect for authority, and is ultimately responsible for its destruction. It is significant that Piggy dies when the conch is smashed.

3) "The Beast" signifies the unknown to the boys and they are afraid of it to the point of being irrational. Only Simon comes to an understanding of the fear that exists within each person. Jack capitalizes on fear and uses it and violence as a weapon to manipulate the boys in his attempts to be the leader. 

Fear is a very real feeling for the boys, once the euphoria of being on a deserted island, with no adult supervision, subsides. The fact that the beast is a figment of the imagination does not make it any less scary. Basic instincts take over when Ralph's leadership style is not sufficient to maintain order and to stop Jack from forcing the boys to accept his "hunter-or-be-hunted approach.