The teachings in the Course are non-dualistic teachings. Should you go back into ancient China or again into India, you would've heard about Advaita Vedanta. Advaita in fact suggests “not two,” and that is a method of talking about the fact that there is a oneness which connects us all. https://www.youtube.com/channel/UCTleG6-484F7WHZD0hAjRRw