Why piggy is useful in the book Lord of the Flies?

Piggy lends an adult perspective and adult suggestions to the boys meetings. Piggy is an outsider who doesn't act, think or speak like the other boys. He is logical, practical and less inclined to wild imaginings than some of the other boys. On a purely practical level without Piggy and his glasses the boys could never have started a fire. Piggy was also the person who suggested, when they thought that the beast was on the mountain top, that they could simply light a new signal fire near the beach. When Ralph pauses when speaking and seems to lose the train of his thoughts (petit mal epilepsy?) Piggy is always on hand to remind him what it was that he meant to say, which is usually reminding the rest of the boys of the need to be rescued.