The Origin of Consciousness in the Breakdown of the Bicameral Mind is a 1976 book by the Princeton psychologist, psychohistorian and consciousness theorist Julian Jaynes (1920-1997). The book addresses the problematic nature of consciousness – “the ability to introspect” – which in Jaynes’ view must be distinguished from sensory awareness and other processes of cognition. Jaynes presents his proposed solution: that consciousness is a “learned behavior” based more on language and culture than on biology; this solution, in turn, points to the origin of consciousness in ancient human history rather than in metaphysical or evolutionary processes; furthermore, archaeological and historical evidence indicates that prior to the “learning” of consciousness, human mentality was what Jaynes called "the bicameral mind" – a mentality based on verbal hallucination. The first edition was released in January 1977 in English. Two later editions, in 1982 and in 1990, were released by Jaynes with additions but without alterations. It was Jaynes's only book, and it is still in print, in several languages. In addition to numerous reviews and commentaries, there are several summaries of the book's material, for example, in the journal Behavioral and Brain Sciences, in lectures and discussions published in Canadian Psychology, and in Art/World. Jaynes's theories In his book, Jaynes reviews what one of his early critics acknowledged as the “spectacular history of failure” to explain consciousness – “the human ability to introspect”. Abandoning the assumption that consciousness is innate, Jaynes explains it instead as a learned behavior that “arises ... from language, and specifically from metaphor.” With this understanding, Jaynes then demonstrated that ancient texts and archeology can reveal a history of human mentality alongside the histories of other cultural products. His analysis of the evidence led him not only to place the origin of consciousness during the 2nd millennium BCE but also to hypothesize the existence of an older non-conscious “mentality that he called the bicameral mind, referring to the brain’s two hemispheres”. In the third chapter of the book, "The Mind of the Iliad", Jaynes states that people of the era had no consciousness. Jaynes wrote an extensive afterword for the 1990 edition of his book, in which he addressed criticisms and clarified that his theory has four separate hypotheses: consciousness is based on and accessed by language; the non-conscious bicameral mind is based on verbal hallucinations; the breakdown of bicameral mind precedes consciousness, but the dating is variable; the