The theme of death in Slaughterhouse Five?

One of the book's most famous lines is "So it goes," repeated whenever a character dies. Billy Pilgrim is deeply passive, accepting everything that befalls him. It makes him able to forgive anyone for anything, and he never seems to become angry. But this acceptance has it problems. When Billy drives through a black ghetto and ignores the suffering he sees there, we see the problem with complete acceptance. Vonnegut values the forgiveness and peace that come with acceptance, but his novel could not be an "anti-war book" if it called on readers to completely accept their world.