More adult in appearance--thinning hair, compromised athletic ability, impaired vision, heavy with physical ailments--Piggy is the voice of maturity in the first chapter of "Lord of the Flies." He is rational and desires order: "We got to do something." He suggests a meeting with the conch used as a call to order.
In the absence of adults, Piggy's is the voice of civilization. But, he only has effectiveness through Ralph, the fair-haired boy who has control as a figure-head. As the trappings of civilization are shed, from the removal of clothing to the painting of faces, Ralph begins to lose control: the shelters are not built and the rescue fire is not watched and goes out. Consequently, Piggy's effectiveness is negated, but he strives to maintain some control by ordering the fire rebuilt on the beach. However, Simon has gone and others have wandered away.
Piggy senses this loss of control and sheds some of his civilized manners. When Ralph splashes him, he retaliates, beating the water and shouting; "Stop it!" He seeks the company of others and suggests a feast. Still, he is the voice of reason: "We just got to go on" although he realizes Jack has won.
It is no coincidence that Piggy's name and the animal that is killed are the same noun. For, civilization is sacrificed to the savage desires of the boys isolated from the controls of adults and other members of society. "They blinded me," Piggy says after his glasses are broken. When he and Ralph try to retrieve them, the vicious Roger throws a rock, destroying the conch and killing Piggy.
Piggy becomes more confident and stands up for himself after Jack steals his glasses.
till the 10th chapter piggy seemed to be wise as he gave wise ideas and indeed we see that he was the only wise boy in the novel.
later in the 11th chapter when his glasses (who were the symbol of wisdom) were stolen by jack and his tribe he started to talk nonsence and became blank from the wise ideas he gave prviousl in the novel.