In Chapter 3, we see the conflict between Jack and Ralph developing Ralph is frustrated in building the shelters with only Simon there to help him. When Jack returns from a fruitless hunting adventure, he defends his attempts by saying:
"We want meat."
"I thought I might kill."
Later, in Chapter 4, the conflict becomes more intense when Jack is able to kill his first pig while Ralph is desperately aware that they have missed an opportunity to be rescued because Jack let the fire go out. Jack defensively states:
"We needed meat."
After the beast (the dead parachutist) is spotted, however, Jack no longer attempts to defend his actions. He tries to overthrow Ralph, and when that attempt is unsuccessful, he starts a tribe of his own. From thence forth, he is a dictator, and his authority is absolute.