As political allegory, the characters of "Lord of the Flies" represent some abstract idea of government. Ralph represents the good-hearted, but not completely effective leader of a democratic society. Piggy is his loyal adviser; he is not able to rule himself because of his physical shortcomings, but he can offer rational and logical advice to his leader for whom he cares deeply. On the other hand, Jack, who rules by hysteria and charisma, is the totalitarian leader who touches the emotional responses of his people.
That Piggy represents the rational side of the boys is evident by his introduction of the conch as the symbol for order. He realizes that the need to build shelters is almost as important as keeping the fire going. When Jack and the hunters threaten to prevent the others from reaching the fire on top of the mountain, Piggy suggests that they build the fire on the beach. Piggy uses words such as "if there's something wrong, there's someone to put it right." Always he appeals to the logical point of view.
When Jack shouts, "Bollocks to the rules!" Piggy tells Ralph,
You got to be tough now. Make 'em do what you want....If you don't blow [the conch], we'll soon be animals anyway. I can't see what they're doing but I can hear.
When the hunters become more powerful, Piggy advises Ralph, "We just got to go on, that's all. That's what grownup would do." He always encourages Ralph whenever Ralph loses courage. When Ralph hesitates,
But we must keep the fire burning. The fire's the most important thing on the island, because, because--
Piggy answers for him, whispering urgently, "Rescue." But, when Piggy is slain, Ralph becomes filled with self-doubt and anxiety as the hunters come after him. Fortunately, he is rescued, but he
wept for the end of innocence, the darkness of man's heart, and the fall through the air of the true, wise friend called Piggy.
From the first, Piggy is compared to Ralph. Compared to the lithe, athletic physique that Ralph possesses, Piggy is fat and short. He is asthmatic and wears glasses. However, despite his unattractive appearance, he is very intelligent and thoughtful, coming up with a number of suggestions to help the boys in their plight. For example, it is he that suggests that Ralph blow the conch to summon the rest of the boys and it is he that goes around asking all the boys their names when they come. He is also loyal to Ralph and to the function of the conch.
His glasses are also richly symbolic of reason and the ability to see. It is highly significant that the boys descend to their lowest point of anarchy when they chose to steal Piggy's glasses and they break.
The fact that Piggy is repeatedly picked on shows sympathy from readers. Even though, Piggy may not be full with confidence and pride, I think he is the smartest of them all especially when it comes to survival and civilizations order. The fact that Piggy relies on the conch shows the audience how much he has respect towards rights and orders and it shows readers that he will always follow them.