Julian Jaynes

American psychologist who wrote The Origin of Consciousness in the Breakdown of the Bicameral Mind — arguing that until approximately 1000 BC, human beings did not have the introspective consciousness we now experience but instead heard the voices of gods as auditory hallucinations from the right hemisphere — and that modern consciousness emerged from the breakdown of this bicameral mind.

Created the most radical theory of human consciousness change in recorded history — Jaynes's bicameral mind thesis (the Iliad's characters do not make decisions but hear divine commands, and this represents actual ancient cognition rather than poetic convention) integrates literary evidence, archaeology, neuroscience, and psychology into a sweeping account of consciousness evolution.