Bicameralism (the philosophy of "two-chamberedness") is a hypothesis in psychology that argues that the human mind once assumed a state in which cognitive functions were divided between one part of the brain which appears to be "speaking", and a second part which listens and obeys—a bicameral mind. The term was coined by psychologist Julian Jaynes, who presented the idea in his 1976 book The Origin of Consciousness in the Breakdown of the Bicameral Mind, wherein he made the case that a bicameral mentality was the normal and ubiquitous state of the human mind only as recently as 3000 years ago.