Jack, who has red hair that symbolizes his association with blood, constantly carries a knife around with him. He is responsible for hunting, and when he at first fails to kill a pig, "he snatched his knife out of the sheath and slammed it into a tree trunk" (page 31). As the novel goes on, Jack becomes increasingly more violent, and his knife is often withdrawn from his sheath. He relies on violence to increase his power. Jack resents Piggy's intelligence, and he wants to rid Piggy of his glasses, the symbol of Piggy's learning. For example, when the boys are lighting a fire in the hope of being rescued, Jack says, "His specs--use them as burning glasses!" (page 40). Jack prefers to use Piggy's glasses to make a fire than to allow Piggy, the resident intellectual, to see.
Later, Jack, constantly seen with a spear in hand and often bloodied from hunting, gives up all attempts to be rescued. Instead, he uses his violence, symbolized by the spear, to take control of the boys and become the de facto leader on the island. The boys follow him in a primitive, violent way and abandon Ralph, who stands for law and order.