I am not an expert in this subject, but listening to the comments, it is consistent with the modern observation that the human brain has two centers of consciousness; inner self and ego. The inner self is older and is shared with animal consciousness. It would be analogous to the center of any animal brain's natural operating system. In humans, our inner self defines our collective human propensities, common to all humans, independent of time and place; defines use as a unique species.
The ego is newer and appears to have evolved with the rise of civilization. The ego can detach from the inner self, since the inner self is more natural and timeless; recorded on our DNA; inner truth, while the ego is more cultural and temporal; learned from outside.
The dualism discussed appears to be about how to strike a balance or how to become an inner self without the ego. It is quite amazing how ancient people could sense such deep aspects of the brain's operating system without modern science tools and still learn to reprogram the code.
The invention of computers offers us a way to create perspective, while the temporal awareness of AI or artificial intelligence may be a timely projection of secondary consciousness to create an understanding of what has been known for a long time.
In my experience, the inner self is not directly wired to the ego; simple duality. Rather it has a juke box of firmware that mediates the inner self to the ego. This diversity of firmware was often projected as the gods of any mythology. Monotheism, was based on an awareness that all the firmware masks had a common foundation; inner self.
There is a wild card that was also sensed, long ago, connected to a manmade addendum, to the natural operating system of the brain, from which the ego would emerge. I call it the Satan subroutine. It was created by language and law. Far Eastern and Western religions often symbolize it with a dragon. It appears to block the entrance to the inner self and is often assumed to be the inner self. From what was said of Buddhism; nothingness, may be connected to getting past the subroutine's noise, to get a clear ear for the inner self; better differentiation of natural and timelessness.
The Satan subroutine appears to have evolved from law, by gaming how the natural brain writes to memory. When memory is written to the cerebral matter, an emotional tag is added to sensory content. Law altered the natural way, since law is a binary memory that implies both good and evil.
The natural brain attaches one main emotional tag per memory; this is good and that is bad. Law require two conflicting tags; fear and rest. This creates conflicting feeling which is not natural. Law is like a two sided coin. It is one thing with two sides, with only one side visible at a time. However the exposed side always implies the hidden side is opposite.Since we are taught to do good, the hidden side is usually the dark side/fear which caused a repression of the natural brain, leading to the subroutine from which the ego would also consolidate. Overcoming the ego brought one in contact with its source, which became a new battle, with quiet and rest on the other side of the subroutine. The inner self is not binary or 2-D. That is the Satan subroutine created by law. The inner self is 3-D or a trinity. Standing on the shoulders of giants.