Piggy is an interesting character who drives the action and plot of Lord of the Flies forward. He is also integral to the symbolism of the novel.
Piggy, although overweight, asthmatic, and unpopular, is the most intelligent and clear-thinking of the boys. He is the one who suggests blowing the conch to gather the boys, an act that redounds to Ralph's glory rather than Piggy's. Piggy seems to have the most concern for the littluns, making the only attempt to catalog the island's residents. Piggy's glasses become a central motif of the book. When Jack breaks Piggy's glasses, he reveals his cruel nature. The glasses are the most sought-after commodity on the island since they are the only means of creating fire, which is necessary for survival and rescue. The theft of Piggy's glasses provokes the climactic conflict of the book, when Piggy himself is murdered. Piggy represents a foil for Simon; his reliance on facts contrasts with Simon's intuition. Piggy isn't without moral flaws, although he is the first to stand up for conscience and societal rules. He is disrespectful toward Simon and ends up taking part in the mob that kills him. Afterward, he tries to rewrite history, denying that Simon was murdered and that he was part of the group. Thus he aids in developing the theme by showing that even the most "civilized" of the boys can fall into savagery due to the depravity of the human heart.
Lord of the Flies allows multiple symbolic interpretations. An obvious one equates Piggy to civilization, adulthood, and order. A psychoanalytical interpretation casts Piggy as the Super Ego, playing the role of the conscience or society's moral rules. According to a geopolitical perspective, Piggy represents the United States, Ralph stands for England, and Jack is Hitler's Germany. Ways that Piggy corresponds to the United States are that he is smart but fat and unhealthy, possesses the utmost in technology, and speaks with a lower-class accent. Yet he sticks close to Ralph, never forsaking him even when others fall away, just as England and the U.S. became the most important allies in the effort to defeat Nazism.
Piggy is an important character not only for his key role in the plot and action of the story, but also because of what his character symbolizes.
Piggy is important because of what he represents. Piggy is the only character that doesn't get pulled down into the base evil that the other characters delve in to. Even Ralph expresses enjoyment at killing a pig and participates in the dance that frenzies the boys so much that Simon is killed.
Piggy represents an adult, civilized world. A world that is ruled by law and order and that punishes violent acts against other people. Piggy understands the need for a leader, and even though he didn't vote for Ralph, Piggy always shows his support to Ralph because Ralph was elected chief.
Piggy is also an important character because of his education and intelligence. Piggy not only knows that a fire is important, but also how his glasses can be used to start the fire. That knowledge makes him important to the story AND to the boys stranded on the island.
Even though Piggy is over weight and has several health problems he is often caught quoting his aunt which provides the only female voice in the story.