Some may be familiar with the book
The Origin of Consciousness in the Breakdown of the Bicameral Mind.
This book argues for the idea of
Bicameralism. The author argues for the idea that Man has only been conscious for maybe as little as 3,000 years. Before that Man mainly existed in a state where one part of his mind, literally spoke to him. Schizophrenia is seen as a throwback to this state in this theory.
It is a very interesting idea, that can relate to or explain many things like hearing God’s voice, or the rise of ancestor worship, where a person would hear the voice of their ancestor.
Something to look into.