In his provocative but critically acclaimed theory about the origin of introspectable mentality, Julian Jaynes argued that until the late second millennium people possessed a different psychology: a "two-chambered" (bicameral) neurocultural arrangement in which a commanding "god" guided, admonished, and ordered about a listening "mortal" via voices, visions, and visitations. Out of the cauldron of civilizational collapse and chaos, an adaptive...