Lord of the Flies is one of my favorite novels, not necessarily from a "I'm going to read this every year!" standpoint but more from a "Damn, I wish I could write like that!" perspective. This is one of the most carefully structured novels I've read; each chapter has a wonderful internal rise and fall, and the plotting and metaphoric shadings in the characterizations are amazing.
In the beginning of the novel, the reader is presented with a group of British boys who have been stranded on a tropical island. The boys are all young, the oldest ones not more than twelve, and the island is seemingly serene and gorgeous. The stage seems set for the boys to have a wonderful romp in paradise, but as disagreement breaks out amongst them, their life on the island becomes increasingly violent and hellish.
On a symbolic level, the novel deals with the effects of war on the human race and the ways in which it can turn Earth, our own used-to-be-Paradise, into a living hell.
Ralph is in many ways the personification of a good-intentioned world leader who must struggle with himself between upholding the law and giving in to his baser instincts.
Ralph realizes the necessity for a structured environment for the boys who look up to him, even if they don't think it's necessary, but at the same time he wants to give in to his own selfish desires. Ralph does not have the inborn charisma of a "natural" leader, but he is the most capable leader amongst the boys. He has the conch, which Golding uses as a symbol of leadership and just government. He is not perfect, but he has the sense to ask advice from boys (such as Piggy) who know more than he does.
Unfortunately, he is not able to maintain control when the boys start to fight. Once he is deposed, he symbolizes the spirit of resistance and the struggle for justice in oppressed people.
In the end, he is shown to be the true leader of the boys, but only after the adult world intervenes in the form of the naval officer arriving to end the chaos.
Piggy represents weakend intelligentsia. His obesity and asthma prevent him from playing and working with the other boys. His isolation and alienation due to his physical problems and his sheltered life with his aunt mirror the separation and alienation of the scientific/academic community from mainstream world affairs.
Piggy's dependence on his glasses -- without which he is nearly helpless -- represents the intellectual elites' dependence on technology and knowledge for their power and survival.
In the end, Piggy is murdered by Roger, much as Pol Pot and other dictators destroyed intellectuals in their own countries to keep their people ignorant and obedient.
Roger represents the senselessly violent factions who are suppressed by the laws of a stable society but who rise to bloodthirsty heights in times of war.
When the boys first arrive on the island, Roger is shy and furtive. When war breaks out between the boys, he comes to the forefront as the main enforcer for Jack, the boy tyrant. Roger's methods of terror and uses of torture mirror the actions of groups such as the Nazis in wartime Germany and the Kmer Rouge in wartime Cambodia. Roger vents his sadism on his fellow classmates, representing genocide within a country.
The only thing that stops Roger is the arrival of the naval officer.
Jack represents both tyranny and the destructive, reckless side of human nature. He has a great deal of charisma but very little foresight; his view of the world is centered on satisfying his own desires for power and pleasure.
His insistence on being called by his last name in the beginning of the book shows that he has a military mindset and a distorted view of himself and his classmates. He doesn't really see anyone, including himself, as being a real person with a heart and soul and feelings.
However, most of the other boys can only see his charisma, and his military bravado makes him seem like the natural leader to follow. But in reality, Jack is a very poor leader, providing only quick, superficial answers to their problems.
When his answers fail, he maintains his hold on the boys with terror and a cult of bloodlust that refocuses the energy of their fears into wild dances and pig hunts.
Jack starts up the war against Ralph and his boys; this mirrors the use of war in dictatorships to distract the public from their real problems and to maintain power. Jack's setting the devastating fire on the island is like the act of a mad dictator starting a nuclear war.
Jack denies his own fears and humanity, hiding behind a mask of war paint. His facade is finally broken down when the naval officer arrives and imposes the order of the adult world.
The Naval Officer
The naval officer who arrives at the end of the novel to put a stop to the boys' madness and take them back to civilization could represent a higher power such as God. But perhaps he's just a wishful deus ex machina employed so that readers aren't completely depressed by having to read about Ralph and his friends being murdered after Piggy.
Regardless of one's interpretation of the officer's symbolism, the ultimate irony of the book is that he "rescues" the boys only to take them back to a world torn by war where none of them have any authority or power over their own lives. And, unlike the officer's stopping the boys' violence, there's not likely to be any higher power to save humanity from the disaster of its own creation.