What does Quentin mean with the response "temporary" in the last part of his section?
There are several approaches that can be taken with this particular idea. It's a challenge to parse the meaning of the work through the use of one word and it should be noted that the use of language should be seen in the larger context and not attempted to make sense outside of it. The idea of "temporary" might be something we can use to see Quentin. If we examine the use of the term in light of the Compson family and Quentin himself, there can be much in way of appropriate use of the term. The exterior of success, being the eldest, being at Harvard, and being the one that might "have it together," is a temporary facade. Additionally, the notion of pain might be something where temporal conditions apply. On one hand, Quentin has trouble reconciling whether or not his incestuous feelings for Caddy are temporary. If they are, then they might not seem valid expressions, and if they are not, then they come into direct conflict with social expectations. The more valid they are and thereby less temporary, the worse the impact. In regards to the pain experienced about the family's dishonor with Caddy's "fall from grace" as well as the notion of honorable ideals changing in a new setting of modernity (thereby being "temporary"), Quentin experiences this in the present. Yet, similar to his feelings about Caddy, if these are "temporary," then the experience of pain is not valid. At the same time, if the pain is not "temporary," then its inescapable nature is excruciating to bear. Perhaps, these ideas are the reason for the use and repetition of the term. Additionally, the idea of time and its use in terms of the style of the writing in the novel might be a part of this. There is much which seems to be both temporary and permanent. Benjy's conception of time is one where events are posited in what makes sense to him, but lies outside the full grasp of others. With Quentin and his watch that he sets to perfect time before he commits suicide, the notion of what is temporary and permanent becomes blurred in his own mind.