Chapter Six of Lord of the Flies brings the isolated boys closer to humanity as a parachutist from an air battle dies in a tree atop a mountain. However, this wafting figure of death and war frightens Sam-n-Eric, who return to the others and testify that they have seen the "beast" atop the mountain. While Piggy wants to stay in the camp, Jack is eager to go after this beast. When Piggy grabs the conch to speak, Jack shouts at him,

"Conch! Conch!....We don't need the conch any more. We know who ought to say things. What good did Simon do speaking, or Bill, or Walter? It's time some people knew they've got to keep quiet and leave deciding things to the rest of us."

Clearly, Jack asserts his tyrannical authority here. Also, his words underscore the beginning of the loss of Ralph and Piggy's civilized method of rule.

After the boys all decide that they will seek the beast, so they set out along the beach. Ralph walks behind, glad to escape responsibility for a time. 

 “Simon, walking in front of Ralph, felt a flicker of incredulity—a beast with claws that scratched, that sat on a mountain-top, that left no tracks and yet was not fast enough to catch Samneric. However Simon thought of the beast, there rose before his inward sight the picture of a human at once heroic and sick.”

This description of the thoughts of Simon indicate that he realizes that the beast has grown from them. That is, the beast is in the boys; for, it is the evil that lies innately within the heart of man. Simon looks sideways at Ralph, but loses his opportunity to define what he feels as he does later.

The characters of Jack and Simon stand at ends with each other. On the one hand, Jack embraces the inherent evil in himself while Simon recognizes this evil as part of every human being, and something to be feared and controlled.