why does danny recount part of the novel by hemingway?

Danny is all over Hemingway's A Farewell to Arms. He recounts the part where Frederick Henry, the novel’s narrator, reflects on how he once didn’t save a bunch of ants on a log in a burning fire. Danny gives somberly points out how cruel people can be. It's difficult to say why he fixates on this passage. I think Danny really doesn't want to become the next tzaddik . He doesn't want the burden of saving people and like Fredrick and the ants, thinks he might very well chose to let people just burn. I know, kind of creepy!