Monism
Monism is like the Platonist crud that posits everything comes from some "oneness" - The Abrahamic faiths are just knock offs of Platonism
We use this term because Ammon uses this term.
Generally if Ammon's using a term often, and you wonder if it's wrong, there's going to be some background to why, and then you'll understand...
You can interpret it as a stand in for Monotheism, which may be more familiar to you