In "Lord of the Flies," the theme of innocence is central to the narrative, illustrating the boys' transformation from civilized children to savage beings. The novel explores the loss of innocence as the boys descend into chaos and violence, revealing the inherent darkness within human nature. Golding uses the island as a microcosm to demonstrate how innocence is fragile and easily corrupted by primal instincts.

The symbolism of blood in the novel highlights the loss of innocence. Jack's fascination with hunting and killing marks the beginning of his descent into savagery. The act of smearing blood on his forehead signifies his embrace of violence. As the boys chant "kill the beast," their innocence is further eroded, and they become engulfed in bloodlust. Even Ralph and Piggy, initially symbols of order and civilization, are swept into the chaos, culminating in the brutal death of Simon. This event cements the triumph of savagery over innocence, as Ralph weeps "for the end of innocence, the darkness of man’s heart, and the fall through the air of the true, wise friend called Piggy."

The novel's ending underscores the irrevocable loss of innocence. When the naval officer arrives, the boys are forced to confront the reality of their actions. The officer's presence, with his "white drill uniform, gun, and gold buttons," contrasts sharply with the boys' savage state. Ralph's tears for "the end of innocence" highlight the profound impact of their experiences. The rescue does not restore their lost innocence; instead, it marks their permanent transformation, as they are reintegrated into civilization with the knowledge of their own capacity for darkness.

Throughout the novel, Ralph represents the struggle to maintain innocence and order. Despite his efforts to uphold the rules and keep the signal fire burning, he ultimately succumbs to the chaos around him. His realization of "the darkness of man's heart" signifies his understanding of the inherent evil within humanity. The fire, initially a symbol of hope and civilization, becomes an agent of destruction under Jack's leadership, further illustrating the loss of innocence.

The boys' descent into savagery is a reflection of the conflict between civilization and primal instincts. Ralph's fear of "us" and his acknowledgment of the "beast" within highlight the internal struggle between reason and emotion. The novel suggests that innocence is not a permanent state but a fragile condition easily shattered by the darker aspects of human nature. The loss of innocence in "Lord of the Flies" serves as a powerful commentary on the inherent evil within humanity and the thin veneer of civilization that masks it.