What is Captain Beatty’s dream about?

Captain Beatty tells Montag that he dreamed of having a furious debate on books, which is meant to confuse and deter Montag from pursuing knowledge and reading literature. Beatty says that in his dream Montag shouted quotes at him, and he cleverly parried every argument by responding with opposing literary quotes. Captain Beatty then proceeds to display his command of literature by quoting Dr. Johnson, Shakespeare, Thomas Dekker, Ben Johnson, Robert Burton, and Paul Valery. The purpose of Captain Beatty describing his dream is to make Montag aware that the same books he reveres also offer opposing points, which makes the pursuit of knowledge difficult and overwhelming. Captain Beatty sums up his argument against literature by telling Montag,

What traitors books can be! You think they're backing you up, and they turn on you (Bradbury, 51).

Beatty then concludes his dream by telling Montag that after their literary argument, he came along in his Salamander and picked Montag up to take him to the station. The entire time Beatty is describing his dream, Faber listens via the green bullet and offers Montag words of encouragement against the captain's persuasive argument.