What are the motifs in Player Piano by Kurt Vonnegut?

Uselessness is a recurring idea. Human beings in the book have an inherent need to feel useful. The machines take over all of the necessary jobs, so the people feel useless. They feel that their lives are pointless. When Hagstrom's wife realizes that he is cheating on her, she cries because she has no use for anyone. The house, she says, runs itself, so her family doesn't even need her as a housewife. Hagstrom himself feels useless in his job, and his affair seems to be the only thing he has in his life. The Reeks and Wrecks despise their jobs because they know that those jobs serve no useful function.