Did he think that Homer must have been a nut case because he wrote such silly epics? Not to mention Virgil or Dante.
In Homer, this would be Athena telling Odysseus what he should do, or Aphrodite telling Paris to run away. It's the voice of a god that suddenly intervenes in human affairs.
Jaynes further says that at the time of the Bronze Age collapse (roughly 3000 years ago), the brain began to be more well-ordered and "the voices" stopped (for most of us). At that point, humans became aware that they were aware, they understood that they could think about thinking, and you could talk to yourself in a deliberative and constructive manner. The birth of consciousness.
Very controversial book, but loaded with interesting ideas.