How we cite our quotes: (Chapter.Paragraph)
Quote #4
I don't want to wake [Tris], but I feel strange, going to meet a girl in the middle of the night without telling her about it. (23.2)
Tobias feels guilty for meeting up with Nita without telling Tris, so he does something crazy after meeting up with her (at least it's crazy by young adult-novel standards): he tells her about it. Honesty: a good way to cleanse your soul of guilt.
Quote #5
And I promised. I promised Zeke I would look after him, I promised. (29.44)
As if Tobias doesn't feel guilty enough about everything, he now feels guilty for basically being responsible for Uriah's death. This motivates him to go into the city and apologize to Uriah's parents, an act that means he's not nearby when Tris decides to sacrifice herself. If he hadn't felt guilty, would Tris have died?