"every man is the arbiter of his own virtues whether or not you consider it courageous is of more importance than the act itself than any act otherwise you could not be in earnest and i you don't believe i am serious and he i think you are too serious to give me and cause for alarm you wouldn't have felt driven to the expedient of telling me you had committed incest otherwise and i i wasn't lying i wasn't lying and he you wanted to sublimate a piece of natural human folly into a horror and then exorcise it with truth"
pg 176
This passage marks the end of Quentin's mental breakdown. The use of literally no syntax or punctuation shows the randomness and swell of his thoughts. Its most definitely a self catharsis, as one cannot tell whether it is a memory of talking to his father, or he is talking to Shreve in the present. He repeats pronouns like I and you one after another, making it more difficult to figure out who he is addressing. He is losing more and more ability to make sense, and has almost descended to the bottom