Free Will vs. Determinism
The novel stacks the deck against free will at every turn. Rumfoord sees the future. The Tralfamadorians have been steering history for millennia. Characters resist their fates and end up exactly where they were predicted to be. Vonnegut doesn't resolve the tension. He just keeps showing how little it matters whether you struggle or comply.
The Absurdity of Human Purpose
The Tralfamadorian reveal is the novel's central joke: humanity's greatest achievements were alien text messages. Vonnegut uses this to attack the idea that history moves toward something meaningful. The joke lands hard because it's not entirely different from how history actually feels when you look at it closely.
Religion as Social Engineering
Rumfoord designs the Church of God the Utterly Indifferent the way an engineer designs a machine. He identifies a social need, creates the conditions to meet it, and installs a theology. The church works. That's the disturbing part. Vonnegut shows that a religion doesn't need to be true to function.
The Randomness of Luck and Privilege
Malachi's wealth is the product of a Bible-based stock-picking system, which is pure chance dressed up as method. The novel treats his privilege as arbitrary and then shows how that arbitrariness poisons his whole life. He never earned anything, so he never built anything, and when it's all stripped away, there's nothing underneath.
Connection as the Only Real Comfort
Every character who finds any peace in the novel does so through connection with another being. Boaz and the harmoniums. Salo and Malachi. Malachi's final hallucinated reunion. Vonnegut doesn't offer hope, but he does offer this: the moments when people genuinely care for each other are the only moments that feel real.