Regarding the sentence you quoted, the author is trying to summarize Brandon's views and I am not confident they are doing so in the most clear manner. I would

Regarding the sentence you quoted, the author is trying to summarize Brandon's views and I am not confident they are doing so in the most clear manner. I would go to source, Brandon, to really understand. That said, I believe (could be wrong) that he is just summarizing a version of deontic logic: https://en.m.wikipedia.org/wiki/Deontic_logic https://en.m.wikipedia.org/wiki/Deontic_logic