What is the purpose of the drawn-out conversation between the narrator and Mr. Emerson's son in Invisible Man

We find out what is exactly in these letters from Dr. Bledsoe. Dr. Emerson's son is outraged at the letter and advises the narrator never to return to school. The letter says to give the narrator hope of returning to school even though he will never be invited back. In the end Emerson's son gives the narrator a lead on a job.