Without them the boys would have never able to have fire.
People value democracy very highly and in the past have fought and even died for it. Although there may be additional symbols present in the novel, I found these to be the most evident and the most important.
Roger represents brutality and bloodlust at their most extreme.
The boys set up a civilization and try to live in the society they have set up. As long as the fire continues burning, it suggests not only that the boys want to return to society, but also that they are still using their intellectual capacity.
Throughout the novel, the author hides powerful messages in some very unlikely places, and Golding's use of this literary technique - symbolism - is the subject of this essay. The island itself serves a dual purpose; it is the symbol of hell as well as paradise.
Democracy, like the shell, is very precious and is easily broken. Symbols are objects, characters, figures, and colors used to represent abstract ideas or concepts.
Simon sees that the evil is not physical but mental towards the end of the book and as he trys to tell the others he is killed, like a martyr of his cause. When his glasses are on he is very insightful and intelligent.