Piggy is the voice of intellect. From the beginning when he talks to Ralph and tells him how to blow on the conch, he is the one who is practical and sees what needs to be done. He constantly reminds Ralph, and the others as much as they will allow him to, that they need to take care of business so that they might be rescued or at least that they might live a more pleasant existence. Simon is the mystical thinker and intuiter. When we first see him, he is marching with the other choir boys and then falls to the sand in a seizure. The seizure is mysterious and so is Simon. He never says a great deal, but he seems to understand much. He is the first to suggest that the beast is not something that is a tangible being. As early as chapter 5, he suggests the the beast on the island is simply them. When Simon comes to the full realization of the source of evil and with that new enlightenment, checks out the dead parachutist and frees him, he tries to share that knowledge with the other boys. In essence, then, the beast kills him because the boys are worked up into such a savage frenzy around their fire that when Simon comes stumbling into the group of boys, they fall on him and with great ferocity, kill him. He is doomed to die with the knowledge of his discoveries locked inside of him. Piggy is doomed to die for the same reason. He also comes to realize that the boys themselves are the problem. Piggy also suggests as early as chapter 5 that he doesn't think the beast is something with claws and teeth. He uses reason to deconstruct the problem on the island though. In chapter 11, he tells Ralph that he will simply go to Jack and try to reason with him. When he does confront Jack and asks which is better - to live with savagery or to try to live a civilized life - Piggy is killed. Both Simon and Piggy saw before anyone else what the source of evil was. For this knowledge, they both were brutally killed, thus proving that they were right.