Bartleby, the Scrivener

Bartleby is one of the most complicated and complex passages, especially for how simply and blatantly that it is written by Herman Melville. It is a tale of some behind the scenes of Wall Street, but it is so much more than that. The Narrator is a property lawyer who has two very animated characters as copyists, Turkey and Nippers, and an "apprentice", named Ginger Nut, who is pretty much the errand boy for the other workers.
Life becomes much more complicated for the Narrator when a man names Bartleby comes to his office for a job as a scrivener. All is well for the first couple of days, Bartleby worked like a machine. Howver, when he is asked to do anything other than copy papers, he answers with a simple response: "I would prefer not to". The Narrator also finds out that Bartleby is living in the office. He tries to fire him, but Bartleby refuses. He becomes like the office's stray dog, or ghost who lurks in the corners. The Narrator is so confused, because he just cannot understand what is wrong with Bartleby. Is he depressed? Is he mentally challenged? is he homeless? The narrator offers all the help he knows how, offering moner, his home, but Bartleby simply "prefers" not to take it. The narrator ends up simply running out of options, and moves offices, leaving Bartleby behind. The next leaser ends up having Bartleby sent to jail, where he starves himself to death.
This passage really makes you question, what purpose did Bartleby serve in the story? Was he a character foil to the narrator? Was his role and relationship with the narrator to show how reasonable people deal with social problems we do not understand or cannot resolve?