The tropical island, with its bountiful food and untouched beauty, symbolizes paradise. It is like a Garden of Eden in which the boys can try to create the perfect society from scratch.
The Lord of the Flies (the Beast)
The "Lord of the Flies," or the beast, inhabits the severed pig head that Jack's hunters stake into the ground and leave as an offering. Simon recognizes that the Lord of the Flies is the savage monster buried in everyone. When the Lord of Flies tells Simon "we are going to have fun on this island," it means they're going to indulge every want and desire, without regard to the rules of civilization. The name "Lord of the Flies" is a reference to the name of the Biblical devil Beelzebub, so on one level, "the beast" is a kind of savage supernatural figure, but mostly it symbolizes the evil and violence that potentially exists in the heart of every human.
The Conch Shell
The conch shell symbolizes the rule of law and civilization. It's used to call assemblies and as a kind of microphone that grants the right to speak to whomever holds it during assembly.
By allowing the boys to create fire, the first necessity of civilization, Piggy's glasses represent science and technology, mankind's power to transform and remake their environment to best suit its needs.
Fire is a complicated symbol in Lord of the Flies. Like the glasses that create it, fire represents technology. Yet like the atomic bombs destroying the world around the boys' island, fire is a technology that threatens destruction if it gets out of control. Fire also symbolizes the boys' connection to human civilization: their signal fire gives them hope of rescue.
Adults symbolize civilization and social order to the boys. But to the reader, the world war raging outside the island makes it clear that the adult "civilization" is as savage as the boys' "civilization" on the island.
A rip in the forest caused by the crash landing of the boys' plane on the island. The scar symbolizes that man, and his savage nature, destroys paradise merely by entering it.
•Look for the red text to track where The Scar appears in: Chapter 1