Bicameral Mentality, Hypnosis, and the Theory of Mind In The Origins of Consciousness in the Breakdown of the Bicameral Mind Julian Jaynes argued that consciousness – our experience of monitoring and controlling our thought and action -- emerged relatively recently in human history. According to Jaynes, hypnosis is a “modern vestige” of an ancient “bicameral” mentality. Some hypnotic phenomena, such as trance logic, the hidden observer, and dissociations between explicit and implicit perception and memory, and the experience of involuntariness do contain hints of bicameralism. On the other hand, Jaynes exaggerated the authoritative role of the hypnotist as a charismatic Svengali-like figure, and downplayed the implications of self-hypnosis. Jaynes also may have overly emphasized the role of the right cerebral hemisphere in hypnosis. In my view, however, Jaynes’s theory does not rely on its ability to explain hypnosis, or even on neuropsychological findings concerning hemispheric specialization and disconnection. In the final analysis, the theory stands or falls on the philological evidence provided by ancient literature concerning the minds of ancient people. I offer a reinterpretation of this evidence from the perspective of the “theory theory” of cognitive development: Odysseus had a theory of mind, but Achilles did not. The origin of consciousness comes with the acquisition and cultural proliferation of a folk psychology based on mental states of belief, feeling, and desire. The hypothesis is supported by findings of cultural variation in the theory of mind, such that “consciousness of consciousness” (Jaynes’s phrase) is not universal – or, at least, not universally found to be useful.