The pause was only long enough for them to understand what an enormity the downward stroke would be. Then the piglet tore loose from the creepers and scurried into the undergrowth, they were left looking at each other and the place of terror, Jacks face was white under the freckles, he noticed that he still held the knife aloft and brought his arm down replacing the blade in the sheath. Then all three of them laughed ashamedly and began to climb back to the track." (Pg. 31).
This is where we first begin to see how the need for survival and the instincts of the boys comes into play in relation to their actions. Jack cannot, yet, kill another living creature. This is the way he hangs on to his life in civilization, and all that he has been taught there. But directly after this, Jack begins to shed that first layer of civility, when he reflects upon the scene. .
"They knew very well why he hadn't: because of the enormity of the knife descending and cutting into living flesh: because of the unbearable blood. .
"I was going to," said Jack. He was ahead of them and they could not see his face. "I was choosing a place. Next time-!" He snatched his knife out of the sheath and slammed it into a tree trunk. Next time there would be no mercy." (Pg. 31).
Jack is shown throughout the story as the type of person who does not like to fail. And when he does, it only makes him even more intent upon doing whatever it is that he failed at. So, in a sense, Jack's number one goal becomes to kill. He sets his sights upon this and does not waver form it. And it is at this point, that the downward spiral of destruction starts, and the boys begin to pry loose the cover of rules and etiquette that has been imposed upon them by society and let their own feelings and instincts run rampant. Golding specifically shows the very intricate break down of the codes of conduct that control the boys in society, letting the reader see just how simple Golding sees it to be for a person, out of the general public and away from the law, to become a servant to his own feelings and to revert to an inherently evil nature.