Human rationality is irrelevant! To this. Human rationality is unrelated to the meaning we're discussing. In fact, it most often limits and/or distorts awareness of the actuality of said meaning. Same for reason, etc.I place them in a different category. Placing everything in one box is a tautology that disregards the ego and our human rationality. And I think the ego is a spiritual product and has reason to exist, as much as our individuality and our ability to discriminate and reason.
The ego is a spiritual expression is true. Of course all states and things are spiritual expression. Even being unaware of the existence of spirit is a spiritual expression. And yes they all exist for a purpose. But that purpose may or may not be beneficial to one's intent.