The narrator is Tyler Durden, and he is not told

The sharper version of the mirrored case, and sharper than Dorian Gray because the split is not between an image and a man but **inside a single voice**. For the whole film the audience attaches to Tyler Durden, and Tyler Durden is supplied entirely by the person narrating: "The Narrator, an unreliable narrator, is not immediately aware that he is mentally projecting Tyler." There is no second person to check him against, which is the condition every other entry on this site has and this one has inverted. The physical evidence is better than the script notes, because the actor supplied it: Edward Norton said "We decided early on that I would start to starve myself as the film went on, while Brad Pitt would lift and go to tanning beds; he would become more and more idealized as I wasted away." One body, two figures, and the divergence was made physically rather than written. What ties it to `the-imaginary-friend` is the mechanism, which is the same mechanism in two epistemic states. An unreliable narrator is a person who knows and maintains anyway. A child with an imaginary companion knows the friend is invented. The Narrator does not know Tyler is invented. **One mechanism, two states of knowing, and the film conceals the difference on purpose** - the reveal is the last ten minutes, by which point the audience has been holding a bond for nearly two hours without knowing there was anything to hold on to. The commercial story is the same story told in money. Studio executives disliked the film and restructured Fincher's intended marketing campaign to cut expected losses; it opened to about $102.4 million and then found its actual audience in home video. The bond is with the narrator. The money followed the bond and ignored the premise.