Insiders and outsiders
The premise of this story is predicated on the conflict and cultural exchange caused by European business ventures in Australia. Bobby sees this from the position of insider, because the Aboriginal people have deep, nearly eternal connections to the land, and the American whalers and European communities disregard that sacred relationship, in a way that causes Bobby's communities to fear them and make them into "outsiders." When Bobby resists the urge to judge Americans as evil, it's because he sees that their "fear of outsiders" is not necessarily helpful or productive.
Harmony versus dissonance
Bobby is not in harmony with his community, and although the scene starts pleasantly enough, although there are signs that point to the two communities being able to live in peace, the novel quickly shows a descent into dissonance and miscommunication and fear. As people become increasingly unable to guess the truth about the other community, they end up ramping up their own paranoia until ultimately, Bobby is left in a catch-22.
Acceptance and fear
Although the two points of view, the European point of view and the Native point of view, are essentially equal, because the humans who believe them are essentially equal, they fail in this novel to understand that just because they can criticize the other people doesn't mean that their criticisms are balanced. Therefore, this theme is introduced, the tolerance meter of acceptance and fear. By being disgusted by foreigners and rejecting them, Bobby's community begins to slide toward violence.
