Although not truly a character, the narrator of The Jungle supplies the most important voice. Because The Jungle is told from a third-person, omniscient point of view, insight into what a character thinks, says, and does isn't available firsthand. Readers are told what happens; therefore, the most telling information readers gain into Jurgis and his family is from the narrator.
Readers need to remember, though, that being all-knowing is not the same as providing reliable or truthful information. The narrator of The Jungle, clearly taking on Sinclair's voice, has a socialist agenda and therefore only reveals what is sympathetic to the socialist cause. The intrusions the narrator makes in the text are glimpses into the thoughts of the characters and they unquestionably shape the characters; readers need to remember to remain objective, especially when the narrator does not. The narrator of The Jungle has a socialist bias, although this bias is not revealed until the end of the text; therefore, readers must understand that the commentary provided during early chapters is designed to make the reader unknowingly sympathetic to the socialist movement.