One of the most telling moments in the novel is when Simon encounters the Lord of the Flies. Amidst all of the mockery and condescension from the pig's head, Golding utilizes the decay and evil of the Lord of the Flies to reinforce one of the most dominant themes of the novel--man's innate capacity for evil:
"'Fancy thinking the Beast was something you could hunt and kill!' said the head. [...] 'You knew, didn't you? I'm part of you? Close, close, close! I'm the reason why it's no go? Why things are what they are?'" (143).
Even though the severed head instructs Simon to forget the whole thing, the reader cannot forget; the destructive force mentioned by the Lord of the Flies manifests itself in the boys' own destructive actions, from the scar left on the island to the killing of the pigs, to the eventual murder of Simon and Piggy. The Lord of the Flies is a visual metaphor for man's own capability for destruction, a theme which resonates throughout the whole of the novel.