Human nature's capacity for both good and evil emerges in the boys' struggle for survival.
The conflict between Ralph and Jack symbolizes the battle between reason and instinct.
The signal fire represents the boys' hope for rescue, but it is ultimately neglected as their primal desires take over.
Simon's encounter with the 'Lord of the Flies' exposes the darkness within humanity.
The destruction of the conch shell signifies the loss of civilization and the collapse of social order.